ISSN 1310-8271 том 19, книга 2, 2013 Volume 19, Book 2, 2013

ISSN 1310-8271

-

,

19, 2, 2013

OF THE TECHNICAL UNIVERSITY - SOFIA

PLOVDIV BRANCH, BULGARIA

Volume 19, Book 2, 2013

Journal of the Technical University Sofia

Plovdiv branch, Bulgaria

Fundamental Sciences and Applications Vol. 19, Book 2, 2013

International Conference Engineering, Technologies and System

TECHSYS 2013

BULGARIA

EDITORIAL BOARD

:

. ..., ... EDITOR-in-chief

Prof. Marin Nenchev, DSc

Eng., DSc Phys., PhD

. -

SCIENTIFIC SECRETARY

Assoc. Prof. Bogdan Gargov, PhD

EDITORS

1. . - 1. Prof. Sonia Tabakova, PhD

2. . - 2. Prof. Michail Petrov, PhD

3. . - 3. Prof. Angel Vachev, PhD

4. . - 4. Prof. Andon Topalov, PhD

5. . - 5. Prof. Dimitar Katsov, PhD

6. . - 6. Prof. Grisha Spasov, PhD

7. . - 7. Prof. Angel Zumbilev, PhD

EDITORIAL BOARD

1. . - 1. Prof. Angel Vachev, PhD

2. . . . ... 2. Prof. Venelin Zhivkov, DSc

3. . ... 3. Prof. Georgi Andreev, DSc

4. . ... 4. Prof. Georgi Totkov, DSc

5. . ... 5. Prof. Emil Nikolov, DSc

6. . ... 6. Prof. Ivan Iachev, DSc

7. . - 7. Prof. Marin Hristov, PhD

8. . - 8. Prof. Ognian Nakov, PhD

9. . ... 9. Acad. Nikola Sabotinov DSc

10. . ... 10. Prof. Marc Himbert DSc

11. . ... 11. Prof. Yasser Alayli DSc

12. . ... 12. Prof. Tinko Eftimov DSc

13. . ... 13. Acad. Yuriy Kuznietsov DSc

Copyright 2013 by Technical University - Sofia, Plovdiv branch, Bulgaria. ISSN 1310 - 8271



Fundamental Sciences and Applications Vol. 19, Book 2, 2013


TECHSYS 2013

BULGARIA

CONTENTS

1 YURIY KUZNIETSOV, HAMUEYLA GERRA, ANGEL POPAROV

GENETICMORPHOLOGICAL APPROACH TO CREATING ANDFORECASTING THE DEVELOPMENT OF CLAMPING MECHANISMS FOR

ROTATING PARTS (PLENARY REPORT-PAPER)

7

2 ABDULKAREEM A.WAHAB ALBIHIGE ......

DESIGN AND FLOW ANALYSIS IN CENTRIFUGAL PUMP15

3 ABDULKAREEM JALIL KADHIM, AHMED WALEED HUSSEIN .. THREE-DIMENSIONAL UPPER BOUND AND FINITE ELEMENT SOLUTIONS FOR

FORWARD EXTRUSION OF RHOMBOIDAL AND SQUARE SECTIONS FROM ROUND

BILLETS THROUGH STREAMLINED DIES

21

4 ALEKSANDAR OSMANLI, ATANAS ILIEV EMPLOYEE-BRAND RELATIONSHIP RESEARCH IN MACEDONIAN

TELECOMMUNICATION COMPANY

29

5 AMIR HOSSEIN DAEI SORKHABI, MAHTALA RASAEI, SOHEILA RAFEI NUMERICAL STUDY OF THICKNESS EFFECT ON RESIDUAL STRESS IN 304L

STAINLESS STEEL WELDED PLATES

35

6 ANGELINA POPOVA, MIHAI CHRISTOV, ALEXEI VASILEV, ANTONINA DJAMBOVA, TODOR DELIGEORGIEV ...

IMPEDANCE STUDY OF QUATERNARY AMMONIUM DIBROMIDES AS ACID

CORROSION INHIBITORS

41

7 ANTONIA LAZAROVA . PRACTICAL AND APPLIED IMPLEMENTATION OF DYNAMIC STATISTICAL

METHODS IN ONLINE BASED QUESTIONNAIRE FOR RESEARCH OF THE

IMPACT OF THE MAIN STRATIFICATIONAL FACTORS ON CONSUMER

BEHAVIOUR IN BULGARIA

45

8 ANTONIO ANDONOV, ZOYA HUBENOVA, VLADIMIR GERGOV ... ANALYSIS OF HUMAN FACTORS IN AUTOMATED CONTROL SYSTEMS

49

9 BONCHO ALEKSANDROV .. IT OUTSOURCING FEATURES AND DEVELOPMENT TRENDS

55

10 BORYANA DIMITROVA, BOYAN IVANOV, DRAGOMIR DOBRUDHZALIEV, NIKOLAY STOYANOV .

OPTIMAL SYNTHESIS AND MANAGEMENT ON SUPPLY CHAIN OF BIODIZEL PRODUCTION AND DISTRIBUTION IN BULGARIA

59

11 BOYCHO BOCHEV ... MARKETING CHANNELS IN TIMES OF ECONOMIC TURBULENCE

65

12 CHAVDAR PASHINSKI, ROUMEN KAKANAKOV, LILYANA KOLAKLIEVA ... SUPERHARD nc-(Al1-xTix)N/a-Si3N4 GRADIENT NANOCOMPOSITE COATINGS FOR

MACHINING TOOLS

71

13 CONSTANTIN ROTARU, MATEI GABRIEL PERICLE, AMADO STEFAN .. AN ANALYTICAL EVALUATION OF NONLINEAR AIRFOIL CHARACTERISTICS FOR

HELICOPTER ROTOR BLADE

77

- 3 -

14 DANIEL DELCHEV, NIKOLAY TONTCHEV .. RELATION BETWEEN THE COEFFICIENT OF WORKABILITY AND THE TYPE OF

MATERIAL FOR PROCESSING STEELS WITH SWARF-FORMATION

83

15 DECHKO RUSCHEV, DIMITAR KATSOV, STILIYANA TANEVA . COMPUTER-BASED AUTOMATED SYSTEM FOR PNEUMATIC TYRES

CHARACTERISTICS DETERMINATION

89

16 DECHKO RUSCHEV, RAYCHO RAYCHEV, DEYAN ZHELEV .. HYDRAULIC STAND FOR TESTING AUTOMOTIVE SHOCK ABSORBERS

95

17 DELYANA DIMOVA .. STUDYING THE DYNAMICS OF THE AVERAGE SALARY AND EMPLOYEES BY

ECONOMIC ACTIVITIES

101

18 DIMITAR DECHEV, NIKOLAI IVANOV, PETER PETROV . OBTAINING AND STUDYING THE PROPERTIES OF ALUMINIUM THIN FILMS

105

19 DIMITAR KATSOV, STILIYANA TANEVA, PEPO YORDANOV, DECHKO RUSCHEV HYDRAULIC SYSTEM FOR TESTING OF PNEUMATIC WHEELS

109

20 DIMITAR STOYANOV .. CURRENT -VOLTAGE CHARACTERISTIC OF A PHOTO RESISTANSE. A PLANE CASE

115

21 DIMO CHRISTOZOV, KIRIL KOLIKOV, BOGDAN GARGOV ... MODELING OF STRATIFICATION IN LIQUID DISPERSE SYSTEMS AT RIGHT AND

OPPOSITE SEDIMENTATION

119

22 DIMO ZAFIROV, HRISTIAN PANAYOTOV UAV RESEARCH AND DEVELOPMENT IN THE PLOVDIV BRANCH OF TECHNICAL

UNIVERSITY-SOFIA (A SURVEY)

123

23 GENNADY MAKLAKOV, PETAR GETSOV . FORCE FEATURES OF THE USE IN THE INFORMATION AND EDUCATIONAL SPACES FOR PREPARATION OF YOUNG SCIENTISTS IN THE AEROSPACE TECHNOLOGIES

129

24 GEORGI P. PASKALEV NONLOCAL BOUNDARY VALUE PROBLEM IN THE CYLINDRICAL DOMAIN - THE

CASE WHEN THE NONLOCAL CONDITION DEPENDS ON THE SPATIAL VARIABLES

135

25 GEORGI P. PASKALEV SHALOVS VARIATIONAL METHOD FOR THE MULTIDIMENSIONAL WAVE EQUATION

141

26 IMAD SHUKRY ALI, ALI HAMZAH NEAMAH .. HEAT TRANSFER ENHANCEMENT USING AIR JET / IMPINGEMENT COOLING

147

27 IVAILO BAKALOV, RUMEN STOYANOV ... MATHEMATICAL MODELING FOR VISUALIZING THE SHIP COMBUSTION ENGINE

(KDVG) - ABC, MODEL V-DZ

153

28 IVAN BARZEV, NIKOLAY ANGELOV . INVESTIGATION ON THE DEPENDENCE OF THE DEPTH OF THE MELT FROM SPEED

AND POWER DENSITY WITH LASER IMPACT ONTO ELECTRICAL STEEL

159

29 IVAN KRALOV ... METHOD FOR REDUCTION OF THE DYNAMIC LOADS AND NOISE, GENERATED IN

THE SPUR-GEAR MESHING OF CYLINDRICAL GEARS

165

30 JIVKO ILIEV, NIKOLAI IVANOV . ANALYSIS OF VIBRATIONAL STATE OF MINE CAGE FOR WINDING MACHINE IN

BABINO COAL MINE, MINE COMPLEX BOBOV DOL

171

31 KONSTANTIN METODIEV, HRISTIAN PANAYOTOV . SUBSTRATUM WATER POTENTIAL MEASUREMENTS UNDER CONDITIONS OF

INDUCED MICROGRAVITY

177

- 4 -


32 MAYA MANASYAN, SERGEY MANASYAN IMPROVED DESIGN OF DRYERS MINE TYPE

183

33 MILCHO TASHEV, PAVLINKA KACAROVA, VASIL TASHEV . KINEMATIC ANALYSIS OF GEARED MECHANISM IN WATER INSTALLATIONS

187

34 MILKO ENCHEV, SVETLANA KOLEVA . PRELIMINARY DIMENSIONAL SETTING UP OF CNC LATHES

193

35 MUSA AJETI, IVAN BADEV, GEORGI KOSTADINOV . COMPOSITIONS GENERATED BY COUPLE OF CONJUGATE COMPOSITIONS IN

EVEN-DIMENSIONAL AFFINE CONNECTED SPACES WITHOUT A TORSION

197

36 NEDYALKA MARKOVA .. ASYMPTOTIC BEHAVIOR OF THE NONOSCILATORY SOLUTIONS OF DIFFERENTIOAL

EQUATIONS OF SECOND ORDER WITH MAXIMA

203

37 NELI KERANOVA, NAKO NACHEV . COVERING RADIUS OF BINARY CYCLIC CODES

209

38 NIKOLA NACHEV, STANISLAV ALEKSIEV, STOYCHO STOEV .. GENERAL TYPES OF ROTARY HYDRAULIC MACHINES

213

39 NIKOLAI ANGUELOV ..... ANALYSIS ON THE PROCESS OF DISBURSEMENTS IN OPERATIONAL PROGRAMS OF

THE EUROPEAN UNION

219

40 NIKOLAI IVANOV, DIMITAR DECHEV, PETER PETROV, POLINA MILUSHEVA .......... STUDYING MEHANICAL PROPERTIES OF TI AND CR - NI THIN FILMS

223

41 NIKOLAJ GANEV .. ABILITIES AND LIMITATIONS FOR X-RAY DIFFRACTION RESIDUAL STRESS

ANALYSIS USED IN MATERIALS SCIENCE AND MECHANICAL ENGINEERING

227

42 NIKOLAY ANGELOV ... NUMERICAL CALCULATIONS FOR DETERMINING OF INTERVALS ON AMENDMENT

OF THE POWER DENSITY ON LASER MARKING OF METALS BY MELTING AND

EVAPORATION

233

43 PETAR DASKALOV, RUMEN MITEV ... FLOW-TURNING USING THE CNC MACHINES

237

44 PLAMEN ROGLEV, DIMO ZAFIROV ... METAMODELS FOR MULTIDISCIPLINARY DESIGN OPTIMIZATION OF UAV

241

45 RADOSTIN DOLCHINKOV, PENKA GEORGIEVA ... SPHERICAL EPY- AND HIPOCYCLOIDS FROM SPACE TOOTH GEAR

247

46 ROSSITZA SARDJEVA, TODOR MOLLOV . APPLICATION OF FREQUENCY MODULATED SCREENING IN DIGITAL

ELECTROPHOTOGRAPHY

253

47 SAMER MOHAMMED ABDULHALEEM, ALI MEERALI AL-ZAMILY, REHAB NOOR AL- KABY

EFFECT OF RADIATION HEAT TRANSFER ON THE TURBULENT NATURAL

CONVECTION AND FLOW IN A BUOYANCY-INDUCED FLOW INSIDE

PARALLELOGRAMIC ENCLOSURE

259

48 SILVIA SALAPATEVA .. ROLE OF TECHNOLOGICAL CONTROL FOR INCREASING THE RELIABILITY OF

PROCESS IN CNC MACHINE TOOLS

265

49 STANKA HADZHIKOLEVA, EMIL HADZHIKOLEV COMPASS-P AN APPROACH TO THE USE OF A CONSOLIDATED MODEL OF A CLASS

OF PROCEDURES

271

- 5 -

50 STEFAN KRUSTEV ... A PHYSICAL MODEL DEMONSTRATING ACHILLES TENDON RUPTURE

277

51 STEFAN KRUSTEV ... VIRTUAL REALITY IN MEDICAL PHYSICS AND BIOPHYSICS

EDUCATION - POSSIBILITIES AND CHALLENGES

281

52 STEFAN STEFANOV, IVAN PRODANOV . STUDY OF EXPLOSION-PROOF PROPERTIES OF INDUCTIVE NEUTRALIZERS

285

53 STILIYANA TANEVA ... INVESTIGATION OF THE LATERAL SLIP OF PNEUMATIC TYRE

289

54 SVETLOZAR ASENOV, ANGELINA CHOZHGOVA .. IMPROVE ON TECHNICAL MAINTENANCE OF AIRCRAFT THROUGH MANAGING THE

OPERATIONAL RELIABILITY

293

55 SVETLOZAR ASSENOV, ANGELINA CHOZHGOVA ... TECHNICAL RESOLUTIONS FOR INCREASING EFFICIENCY OF SOURCES OF PRESSURE OF HYDRAULIC SYSTEM OF MILITARY AIRCRAFT

299

56 TANYA GIGOVA THE STATUS OF THE BULGARIAN INDUSTRY WITHIN THE FRAMEWORK OF THE

GLOBAL ECONOMIC CRISIS

303

57 TEOFIL IAMBOLIEV INTERCRYSTALLINE CORROSION OF 1.4301 AUSTENITIC STAINLESS STEEL WELD

JOINTS

309

58 TEOFIL IAMBOLIEV PROPERTIES OF STAINLESS STEEL 1.4404 (AISI 316L) GTA WELDS

315

59 TODOR TODOROV ... ANALYSIS OF SIMPLICIAL REFINEMENT STRATEGIES IN SPHERICAL TYPE DOMAINS

321

60 TONI MIHOVA, HRISTINA DAILIANOVA .. ECONOMIC RECOVERY THE EXPERIENCE OF SMALL AND MEDIUM-SIZE

ENTERPRISES IN EUROPE

325

61 TONI MIHOVA ... SMALL AND MEDIUM ENTERPRISES ECONOMIC DEVELOPMENT AND

COMPETITIVENESS

331

62 TRAYAN STAMOV PERSPECTIVES IN RESEARCH AND USING OF EMOTIONS IN CONTEMPORARY

TRANSPORT DESIGN

335

63 VAHIDEH VAHDATPANAHI SH., AMIR HOSSEIN DAEI SORKHABI, SIAMAK HAGIPOUR .

PREDICTION OF IRON RATIO IN METAL INTER GAS WELDING WITH COPPER AND BRASS WIRES USING FUZZY LOGIC MODEL

341

64 VALYO NIKOLOV . MECHANICAL MATHEMATICAL MODELING OF THE TILTING PROCESS OF LIFTING

MASTS OF FORKLIFT TRUCKS WITH LOAD

347

65 VASIL PETKOV . TRADE RELATIONS BETWEEN TAIWAN AND BULGARIA

351

66 VIARA SLAVIANSKA ... REDUCTION OF LABOR EXPENSES A STRATEGY FOR SURVIVAL IN CONDITIONS OF

CRISIS?

357

67 YURIY KUZNETSOV, SERGEY SAVITSKY, BOGDAN GARGOV, ANGEL POPAROV . WORKING MACHINE-STAND FOR THE PROCESSING OF THE POLYGONAL HOLES

363

- 6 -


Journal of the Technical University Sofia Plovdiv branch, Bulgaria Fundamental Sciences and Applications Vol. 19, 2013 International Conference Engineering, Technologies and System TECHSYS 2013 BULGARIA

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GENETICMORPHOLOGICAL APPROACH TO CREATING AND FORECASTING THE

DEVELOPMENT OF CLAMPING MECHANISMS FOR ROTATING PARTS

YURIY KUZNIETSOV, HAMUEYLA GERRA, ANGEL POPAROV

Abstract: The problem about creating new technical schemes can be successfully solved inmodern science by using a new methodological approach which includes systematic analysis,

principles of evolution, morphological analysis, and other methods for searching technical

solutions.

In the present work problems connected with the evolution, development and synthesis of the

clamping devices (chucks) for parts with different forms are considered. Different principles and

laws of mechanics are used in the suggested classification of the interaction nature between the

clamping element and the object of clamping. Amongst them are the principle of the topological

invariance of the field sources, the symmetry principle, the principle of equality, the principle of

conservation of the basic mechanical and other transformation energy, the law of conservation of

energy, D'Alembert's principle, and the Hooke's law.

Keywords: clamping devices, clamping elements, collets chuck, power (force) flows

- 7 -

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Kuznyetsov Yuriy Nikolaevich National Technical University of Ukraine Kyiv Polytechnic Institute 37 Prospect Peremogy, 03056 Kiev, Ukraine E-mail: [email protected] Hamueyla Gerra Agostinho Neto University Avenida 4 de Fevereiro 7 Luanda 3350, Angola E-mail: [email protected] Department of Mechanical Engineering Technical UniversitySofia, Branch Plovdiv 25 Tsanko Dystabanov St. 4000 Plovdiv BULGARIA E-mail: [email protected]

29.01.2013 .

- 14 -

mailto:[email protected]://mail80.abv.bg/app/servlet/sendmess?ac=sab&[email protected]

Copyright 2013 by Technical University Sofia, branch Plovdiv, Plovdiv, BULGARIA. ISSN 1310 - 8271



Fundamental Sciences and Applications Vol. 19, 2013


TECHSYS 2013

BULGARIA

DESIGN AND FLOW ANALYSIS IN

CENTRIFUGAL PUMP

DR.ABDULKAREEM A.WAHAB ALBIHIGE

Abstract: This research deals the flow analysis in the centrifugal pump and design of

centrifugal pump. Centrifugal pump is analyzed by using single stage end suction.

The research proposes a design method which may be used to evaluate the detailed of an

impeller and volute of pump. The design of a centrifugal impeller can be used the layout of the

impeller for the selected angles and areas.

The design depends upon the skill and experience of the designer for the best results. The

basic design elements necessary to define the impeller proportions. The design of centrifugal

pump involves a large number of interdependent variables so there are several possible designs

for the same design point. Specific speed is used to classify impellers on the basis of their

performance, and proporations regardless of their actual size or the speed at which they

operate.

.

Key words: impeller, volute, specific speed, head, velocity.

1. Introduction

The pump is converting of mechanical energy to

hydraulic energy of the handling fluid to get it to

required place or height by the centrifugal force of

the impeller blade. A pump transfer mechanical

energy from some external source to the fluid

flowing through it and losses occur in any energy

conversion process. [1]

The energy transferred is predicted by the

Euler equation. The kinds of loss of centrifugal

pump can be differentiated in internal losses and

external or mechanical losses. The internal losses

are hydraulic losses or blade losses by friction,

variations of the effective area or changes of

direction losses of quantity at the sealing places

between the impeller and housing at the rotary shaft

seals. The external or mechanical losses in sliding

surface losses by bearing friction or seal friction. [1]

The difference in design details is dictated

mostly by the application and mechanical

requirements. Every pump consists of two principle

parts, an impeller, and pump casing. As a result of

the impeller action, liquid leaves the impeller at a

higher pressure and higher velocity than exist at its

entrance. The velocity is partly converted into

pressure by the pump casing before it leaves the

pump through the discharge nozzle. This conversion

of velocity into pressure is accomplished either in a

volute casing or in a diffusion casing of the pump.

[2]

The choice of a suitable flow path for a

centrifugal impeller is almost prerequisite for

completely defining the entire passage geometry.

The boundary values of the relative velocity

components are known from the inlet and outlet

velocity vector diagrams (analysis carried out

assuming zero prewhirl) which resulted from the

previous preliminary design stage. For a specified

value of the impeller length along its axis of

rotation a desirable total relative velocity schedule

is prescribed. The choice is mainly based on

achieving acceptable uniform rate of diffusion. [4]

2. Specific speed (Ns&Nsm)

Specific speed is very useful parameter for

engineers involved in centrifugal pump design and

For application. For the pump designer an intimate

knowledge of the function of specific speed is

the only road to successful pump design. For the

application, specific speed provides a useful means

of evaluating various pump lines. For the user

specific speed is a tool for use in comparing various

pumps and selecting the most efficient and

economical pumping equipment for his plant

application.

- 15 -

Specific speed is always calculated at the best

efficiency point with maximum impeller diameter

and single stage only, there are two formula of

specific is:

Nsm = (1)

Which is calculated the base of operating

conditions (rpm, m3/s, and m). And the other

formula of specific speed is:

Ns=3.65 (2)

Which is calculated the base of operating

conditions (rpm, 0.075 m3/s, m). The equations

1&2 shows that a fixed value of the specific speed

described all operating conditions ( N ,Q ,and N )

that can be satisfied by similar pumps . This

physical significance of equations 1 &2 is also the

most useful definition for the specific speed itself.

Although it has thus been demonstrated that

the specific speed can be presented in different

forms, all these expressions have the same physical

significance, any fixed value of the specific speed

describes a combination of operating conditions that

permits similar flow conditions in geometrically

similar pumps. [6

For the practical application of the concept of

specific speed, it is equally important to consider

the physical significance of differences in specific

speed. From the given definition, it follows that

operating conditions of different specific speeds

cannot be satisfied by similar pumps with similar

flow conditions, i.e., any change in specific speed

definitely requires a corresponding change in the

geometric form of the pump and/or in the flow

conditions. This important relation between the

specific speed and the geometric design of the

pump. [6]

3. Flow analysis

Two- dimensional models for centrifugal or

radial pump begin with analysis of the flow in a

radial cascade (Fig.1).There exist simple conformal

mappings that allow potential flow solutions for

linear cascade to be converted into solutions for the

corresponding radial cascade flow, though the

proper interpretation of these solution requires

special care. The resulting head/flow characteristics

for frictionless flow in a radial cascade of infinitely

this logarithmic spiral blade. [3]

Potential flow solution in which the vorticity is

zero. This solution would be directly applicable to

static or nonrotating radial cascade in which the

flow entering the cascade has no component of the

voracity vector in the axial direction. This would be

the case for a nonswirling axial flow that is a

deflected to enter a nonrotating, radial cascade in

which the axial velocity is zero.

But, relative to a rotating radial cascade, such an

inlet flow does have vorticity, specifically a

vorticity with magnitude 2 and a direction of

rotation opposite to the direction of rotation of the

impeller.

Consequently, the frictionless flow through the

impeller is not irrotational, but has a constant and

uniform vorticity -2.The rotation solution has no

through flow, but simply consists of rotation of the

fluid within each blade passage, as sketched in Fig.

(2). [3].

Fig. 1. Schematic of the radial cascade

Fig. 2. A sketch of the displacement component of

the inviscid flow through a rotating

radial cascade. [3]

4. Slip factor and incidence loss

In the derivation of Euler's pump equation it is

assumed that the flow follows the blade. In reality

this is, however, not the case because the flow angle

usually is smaller than the blade angle. This

condition is called slip. Nevertheless, there is close

connection between the flow angle and blade angle.

An impeller has endless number (infinite) blades

which are extremely thin, and then the flow lines

will have the same shape as the blades. When the

flow angle and blade angle are identical, then the

flow is blade congruent. [5]

The flow will not follow the shape of the

blades completely in a real impeller with a limited

- 16 -


number of blades with finite thickness. The

tangential velocity out of the impeller as well as the

head is reduced due to this. When designing

impellers, we have to include the difference

between flow angle and blade angle. This is done by

including empirical slip factors in the calculation of

the velocity triangles. It is important to emphasize

that the slip is not a loss mechanism but just an

expression of the flow not following the blade. [5]

Incidence loss occurs when there is a

difference between the flow angle and blade angle

at the impeller or guide vane leading edges, as

shown in Fig.(3).

Fig. 3. Velocity triangles where indicates the

velocity with slip. [5]

A recirculation zone occurs on one side of the blade

when there is difference between the flow angle and

the blade angle. [5]

The recirculation zone causes a flow contraction

after the blade leading edge. The flow must once

again decelerate after the contraction to fill the

entire blade channel and mixing loss occurs as

shown in Fig. (4a).

At off-design flow, incidence losses also occur

at the volute tongue. The designer must therefore

make sure that the flow angles and blade angles

match each other so the incidence loss is

minimized. Rounding blade edges and volute casing

tongue can reduce the incidence loss. The

magnitude of the incidence loss depends on the

difference between relative velocities before and

after the blade leading edge and is calculated using

the following model (pfleiderer 1990).

Hloss,incidence = (3)

Where, is empirical value which is set to

0.5 to 0.7 depending on the size of the recirculation

zone after the blade leading edge, and Ws is

difference between relative velocities before and

after the blade edge using vector calculation, as

shown in Fig.(4b).

Fig. 4a. Incidence loss at inlet to impeller.

Fig. 4b. Nomenclature for incidence loss model. [5]

Incidence loss is alternatively modeled as a

parabola with minimum at the best efficiency point.

The incidence loss increases quadratically with the

difference between the design flow and the actual

flow, as shown in Fig. (5).

Fig. 5. Incidence loss as function of the flow.

The centrifugal force creates a secondary vortex

movement because of the difference in rotation

velocity between the fluid at the surface of the

impeller and the fluid at the pump, as shown in

Fig.6

The secondary vortex increases the disk friction

because it transfers energy from the impeller

surface to the surface of the pump casing.

Fig. 6. Disk friction on impeller.

5. Procedure of design

Firstly, must be chose the design parameters for the

pump, head, discharge, rpm. We are taken the

values for these parameters: Q = 0.0167 m3/s, H =

- 17 -

70m, speed = 2900 rpm, liquid = water, Entry =

one, Stage = one.

1. Specific speed (Ns &Nsm )( equation 1

and equation 2)

The values of Ns for centrifugal pump with one

entry suction and with one stage are (40 300).

2. Volumetric efficiency (Q):

There is empirical equation for calculate Q

Q = (4)

3. Inlet discharge (Q'):

Q'= (5)

4. Diameter of inlet pipe (Do):

Do = Ko (6)

Ko is coefficient, the values of it from 3.5 to 6.5.

5. Velocity of liquid at the inlet pipe (Co):

Co = (7)

= (8)

is coefficient, the values of it from 0.06

to 0.08

6. Diameter of impeller at inlet (D1):

D1 =0.8Do to Do (9)

7. Hydraulic efficiency (H):

There is empirical equation for calculate

the H ,

H = 1 - (10)

Do in mm

8. Mechanical efficiency (m):

There are two types of mechanical

efficiency:

(8.1) Internal mechanical efficiency (mi):

There is empirical equation for

calculate mi

mi = (11)

(8.2) External mechanical efficiency (me):

This loss is due to coupling, bearing, and

sealing, and difficulty for estimate the value of

this efficiency, therefore assume the value of it

from 0.96 to 0.98.

Therefore, m = mi me (12)

9. Total (overall) efficiency (t):

t = Q H m (13)

10. Output power (Po):

Po= Q H = g Q H (14)

11. Input power (Pi):

Pi= (15)

12. Power of motor (Pm):

Pm = from 1.1Pi to 1.2Pi (16)

13. Diameter of shaft (d):

d= (17)

Mt is Tensional moment, is tensile stress

Mt =9950 (18)

Pmax in kW

The values of from 300X105 to 500X10

5

14. Diameter of hub (dB):

dB =from 1.2d to1.5d (19)

15. Meridian velocity of liquid before inlet of

impeller ( ):

= Co (20)

Meridian velocity of liquid after inlet of

impeller ( Cm1):

Cm1= k (21)

K1 is coefficient of constraint at inlet, the

values of k1 from 1.1 to1.2

17. Blade width of impeller at inlet (b1):

b1= (22)

18. Peripheral velocity of impeller at inlet ( u1):

U1= (23)

19. Angle of blade at inlet ( 1L):

The blade angle at inlet 1L is bigger than the

flow angle at inlet 1 , from the velocity diagram at

inlet (assume there is no prewhirl of flow at inlet)

that is mean, there is no inlet guide vanes, i.e. 1 =

90o , C1 = Cm1

tan 1 = (24)

1L = 1 + (25)

is angle of attack; the values of it are from 3o

to 8o.

20. Relative velocity of liquid at inlet of impeller

(W1):

From velocity triangle,

W1 = (26)

21. Peripheral velocity of impeller at outlet (u2):

u2 = (27)

is head coefficient, the values of it are from

o.45 to 0.65

22. Diameter of impeller at outlet (exit) (D2):

D2 = (28)

23. Meridian velocity of liquid at outlet of

impeller ( ):

= from 0.7 to (29)

24. Tangential component of absolute velocity

for liquid at outlet (Cu2):

Cu2 = u2 u2 (30)

25. Slip factor ( ): The slip is the difference between the

theoretical tangential components of absolute

velocity of liquid and the actual tangential

component of absolute velocity, because there is

- 18 -


difference between the angles 2&2L .

= 1 - = 1 (31)

26. Meridian velocity of liquid before outlet of

impeller (Cm2):

Cm2 = k (32)

K2 is coefficient of constaint at outlet; the

values of it are from 1.05 to 1.1

27. Angle of blade at outlet (2L):

Sin2L = . . sin1L (33)

Chose the value of from Fig. (7) according

the value of Ns

Fig. 7. Relation between w1/w2 and Ns [7]

28. Width of blade at outlet ( b2):

b2 = (34)

29. Number of blades of impeller (z):

Z = 6.5 sin (35)

30. Pitch of blades at inlet of impeller (t1):

t1 = (36)

31. Pitch of blades at outlet of impeller (t2):

t2 = (37)

32. Thickness of blade at inlet measure on the

circle of radius r1( 1):

k1 = (38)

33. Thickness of blade at inlet measure on the

middle line (1):

1 = 1sin 1L (39) 34. Thickness of blade at outlet measure on the

circle of radius r2( 2):

K2 = (40)

35. Thickness of blade at outlet, measure on the

middle line (2):

2 = 2 sin 2L (41)

36. Capacity Coefficient ():

= (42)

37. Head coefficient ():

= (43)

38. Net positive suction head required (NPSHr):

NPSHr = 0.001046 N3/4 Q2/3 (44)

39. Suction specific speed (Nss):

Nss= (45)

40. Diameter of inside of volute ( D3):

D3 = kH D2 (46)

KH is coefficient, estimated it by the values

of Ns.

41. Width of volute at inlet (b3):

b3 = b2 + (0.02 to 0.05) D2 (47)

42. Average velocity of liquid at volute (Cum):

Cum = kcum (48)

Kcum is coefficient, the values of it depends

on the values of Ns.

43. Design of Volute:

Athr = (49)

In which, Athr is throat area of volute; Cthr is

velocity of liquid at throat.

From Law of free vortex,

= C (50)

In Which C is constant of free vortex, the

value of C 0.9

r4 r2 + t + rthr (51)

t is thickness of tongue of volute.

Av = Athr . (52)

In which Av is the annulus area between the

impeller and outer diameter of volute for each

angle v ( v from zero to 360)

Cthr = . u2 (53)

Fig. 8. Nomenclatures of volute. [8]

- 19 -

Fig. 9. Relation between the values of Cthr/u2 and

Ns.

Av=Athr , r , rv = r3 + r

ro = rv + r

r is the radius of annular area between the

impeller and the outside diameter of volute

for each angle.

rv is the radius of center to the center of

annular area for each angle.

ro is outside radius of volute for each angle.

6. Conclusions:

1. In design flow, the wake or boundary layer on

the suction surface may be quite thin, but as the

flow coefficient is decreased, the increased

incidence leads to large wakes. Clearly, the

nonuniformity of the discharge flow implies on

effective slip due to these viscous effects.

2. The slip will not only depend on the geometry

of the blades but will also be a function of the

flow coefficient and the Reynolds number.

3. The design of centrifugal pump is difficult

subject, because the designer firstly must be

know and understand deeply the hydrodynamic

fundamentals of the centrifugal pump and

know becarfully the importance each

component of the pump.

4. The impeller of the pump is heart of the pump,

therefore the requirements for design of it is

very important.

5. The design of pump does not depend on thetheoretical relation only, but it depends on the

experience of the designer in the field of

application of the pumps, and also the design

depends on the experimental and empirical

relations. In these relations, there are various

coefficients and factors, the designer must be

choosing the correct values of them and in the

suitable ranges.

REFERENCES

1. Khin cho Thin, Mya Khaling, and Khin

Manng Aye (Design and performance Analysis of

centrifugal pump).World Acadency of Science,

Engineering and Technology 46 1946.

2. A.J.Stepanoff, PhD (Centrifugal and Axial

Pump)2nd

Edition 1957.

3. Christopher Earls Brennen (Hydrodynamic of

pumps). Concepts NREC 994.

4. Sarim Al-Zubaidy (Preliminary of Design of

centrifugal impellers using optimization

Techniques).Transations of the ASME, Journal

of fluids engineering, June 1994, vol.116.

5. GRUNDFOS, Researches and Technology, the

centrifugal pump 2005.

6. George F. Wislicenus (Fluid mechanics of

Turbomachinery) First Edition 1947.

7. Zlatariv (Turbopumps and Fans) Technical/

Sofia 1998.

8. J.Karassik ( Centrifugal pumps ) 1998

Department of Mechanical Engineering

University of Babylon / College of

Engineering

Hilla City

Iraq

e-mail: [email protected]

13.02.2013 .

- 20 -

mailto:[email protected]



Fundamental Sciences and Applications Vol. 19, 2013


TECHSYS 2013

BULGARIA

1. Introduction:

Extrusion is a metalworking process, in

which the raw material is forced through a die to

produce long, straight, semi-finished metal products

such as bars, solid and hollow sections, tubes, wires,

and strips .Non-symmetric extrusion means that

both the deformation process and outgoing product

is unsymmetrical in shape about the central axis and

mostly used to produce shaped sections in industry

such as square sections, L-shape, T-shape U-shape.

In extrusion, mechanical properties of the material,

frictional condition at the toolworkpiece interface,

extrusion ratio and die profile, are among the

important parameters that significantly affect the

desired characteristics of the product [1]. the

optimization of these parameters has been one of the

most important tasks attention of many researchers.

Extrusion die profile can be conical or curved. In

the past, due to the difficulty in manufacturing of

non-conical dies, most of research works concerned

with the optimization of rod extrusion die geometry,

focused on conical dies, such as that performed by

Avitzur [2] on the optimization of die angle by the

upper bound method. Nowadays, by use of

computer numerical control (CNC) machines, and

therefore, the case of manufacture of complex die

shapes, many pieces of research work have been

performed on the optimization of curved die

profiles. Chen and Ling [3] gave upper bound

solutions to axisymmetric extrusion problems; they

used three basic kinds of axisymmetric curved dies,

namely, the cosine, elliptical and the hyperbolic

types and transformation techniques used in order to

achieve a mathematically consistent analysis.

D.Y.Yang, C.M.Lee and J.H.Yoon [4] are used

finite element method to extrude the shape function

through curved dies. Lee et al. [5] designed the

optimal die profile for hot rod extrusion that could

yield more uniform microstructure. Nagpal and

Altan [6] presented new die designs, which had

curved surfaces and improved the upper bound on

extrusion pressure. In fact, the shape of the die

designed by theses authors was so good that it was

THREE-DIMENSIONAL UPPER BOUND AND FINITE

ELEMENT SOLUTIONS FOR FORWARD EXTRUSION OF

RHOMBOIDAL AND SQUARE SECTIONS FROM ROUND

BILLETS THROUGH STREAMLINED DIES

ABDULKAREEM JALIL KADHIM, AHMED WALEED HUSSEIN

Abstract: The increasing interest in the modeling of metal-forming processes in recent years has

brought the development of different analytical and/or numerical technique. In this paper, upper

bound and finite element solution are made for a steady-state three-dimensional extrusion of

rhomboidal and square sections through a streamlined dies to predict the required power and to

show the stresses and strains distribution in the die and billet through the extrusion process . A new

method of die surface representation using blending function, and trigonometric relationships, is

proposed by which smooth transitions of die contour from the die entrance to the die exit are

obtained. The upper bound extrusion pressure is obtained based on derived a general velocity felid.

The effects of area reduction, the optimum relative die length, the shape of stream function and

frictional conditions are also discussed. The results are in a good agreement with that obtained by

other research workers.

Keywords: Upper bound method; Finite element; Simulation; Streamlined dies; Extrusion process.

- 21 -

used in many other works to come. Gunasekera and

Hoshino [7] used upper bound solution for extrusion

of polygonal sections from bound billet through

converging and curved dies .Kiuchi et. al. [8]

introduces a new concept in the upper bound

analysis of extrusion and drawing of shape sections

where the rotational and axial velocity component

were approximately assumed. However, there are

very few reports of 3-D mathematical and FEM

models deals the extrusion of rhomboidal and

square sections from round billet throughout

streamlined dies so, in this paper, a 3-D upper

bound mathematical model and FEM simulation by

ANSYS software will consider in order to show the

effect of die length, area reduction, friction factor on

total relative extrusion pressure and also the stresses

and strain distributions throughout the extrusion

process.

2. Velocity Fields:

Figure (1) shows the schematic diagram of

the shape and dimensions of the general die in

cylindrical co-ordinate systems in which the y-

direction is coincident with the extrusion axis.

When the cross sectional shapes of both the

entrance and exit of the die are given by analytical

functions and , then intermediate

sectional contour can be blended as

follows:

------ (1)

The streamline function f(y) is given by:

------- (2)

(3)

Equation (3) satisfies the condition of zero slopes at

entrance and exit of the die respectively. The

boundary limits for the die surfaces are given by:

Therefore, Eq.(1) becomes,

(4)

For the exit rhombus section shown in

Fig.(2) let, (2w1) is the length of the rhombuss

diagonal that coincident with x-axis, (2w2) is

the length of the rhombuss diagonal that

coincident with y-axis, (DR) is the ratio of the

vertical to the horizontal diagonals

,and let (Ro) is the radius of the billet.

Figure (2) shows that when (=45o or DR=1), the

rhombus section has perpendicular sides hence, the

square sections are special case from rhombus

sections when DR=1.Due to the similarity of the die

about the x and -y axis, the first quarter will be

considered .Assuming that the sector AB is

gradually transferring to the straight line CD when

changes from 0 to , hence, the equation of exit

straight line is given by,

(5)

By knowing that x=r cos() and y=r sin() then the

last equation becomes:

(6)

From the trigonometric relationships, we note that:

(7)

By the comparison with Eq.(6), hence Eq.(6)

becomes:

(8)

Where:

the function that describes the exit section of

the die.

(In rad)

Hence, the surface equation of the die that

describes the extrusion the Rhomboidal sections

from the round billets i.e. Eq.(4),becomes,

- 22 -

(9)

Fig. 2. First quarter of the die.

Figure (3) shows the final die surface which drawn

in MATLAB 7.11 when area reduction

60%,Ro=20mm, L/Ro=1 and DR=0.8.

Fig. 3. The die surface.

Throughout this analysis, the following assumptions

are employing [8, 10, and 11]:

i. The work material i.e. the billet material is

isotropic and homogeneous and the die is

assumed rigid body.

ii. The elastic strain is neglected.

iii. Effect of temperature between the round billet

and the die is neglected and the process is

assumed isothermal.

iv. The longitudinal velocity, Vy, is uniform at each

cross-section of the material in the die.

v. The Von-Misses yield criterion is assumed

applicable.

vi. The rotational velocity component

is expressed as product of two functions as

follows:

(10)

The condition of volume constancy in cylindrical

co-ordinate system is expressed by next equation:

(11)

From here, the velocity fields equations are derived

as:

(12)

(13

(14)

Where vo is the billet velocity and is the angle of

symmetry.

3. The Strain Rates:

According to cylindrical co-ordinate system,

the strain rates components are defined as follows

[8,9]

(15)

Total effective strain rate according to Von-Misses

criterion is given by

(16)

4. Upper Bound Solution:

The upper bound formulation is described as

follows:

- 23 -

(17)

Where:

and,

Here, J1 is the work dissipated for internal

deformation; 0 is the yield stress in uniaxial

tension. J2 is the work dissipated at surfaces of

velocity discontinuity at the entrance and exits of

the die respectively due to change in metal velocity.

In this analysis this power will vanish because f(y)

has zero slop at inlet and exit of the die respectively,

J3 is the work dissipated due to friction at the die-

workpiece interface and is a friction factor. In

order to find the power losses due to plastic

deformation J1 and power losses against the friction

J3, the Gauss quadrature method used to evaluate the

above volume and area integrals. Finally the relative

extrusion pressure can be written as:

(18)

5. Finite Element Simulation:

The finite element method (FEM) is a

numerical approach by which a set of partial

differential equations can be solved approximately.

FEM modeling a body by dividing it into an

equivalent system of smaller bodies or units (finite

elements) interconnected at points common to two

or more elements (nodal points or nodes) and / or

boundary lines and/or surfaces is called

discretization . In the finite element method, instead

of solving the problem for the entire body in one

operation, we formulate the equations for each finite

element and combine them to obtain the solution of

the whole body. In this research the finite element

code ANSYS (V11) was used. It is powerful

software used to solve both linear and nonlinear

problems in engineering. Many steps are required to

build the geometrical model:

A- Solid model creation: - Solid model built by

using key points, lines, areas and volumes .In

this research the key points were determined by

using MATLAB 7.11 ANSYS interface.

B- Defining element type: - The Solid billet, the

die, and the container are all modeled by using a

3-D 20-node tetrahedral structural solid element,

named as SOLID95. It can tolerate irregular

shapes without as much loss of accuracy also it

has plasticity, creep, stress stiffening, large

deflection, and large strain capabilities [18].

Contact elements, namely CONTA174 and

TARGE170, have been created between billet-

die and billet-container interfaces. Coulombs

fiction was assumed. The number of element in

the case of SOLID95 was 11282 and elements

CONTA174 and TARGE170 were 652 and 1292

respectively.

C- Defining and editing the element real

constants: - The real constants are properties

that depend on the element type, such as gap

size and initial conditions...etc.

D- Material Properties for Die and Billet:- The die

is made from tool steel, which as is well-known,

has isotropic properties

.The billet material used in this simulation

is Aluminum alloy (AL) which assumed

bilinear isotropic hardening and has modulus of

elasticity (E) of 68 Gpa, tangent modulus (ET)

of 0.1 Gpa, yield stress (y) of 70.2 Mpa and

Poissons ratio of 0.3.

E- Meshing the model: Free meshing is applied

to entire model.

F- Apply Loads and obtain the nonlinear Solution: In this step, analysis type (static),

analysis options (large deformation, equation

solver, etc.), boundary conditions, and the

loading were conducted in the form of a

prescribed displacement. This was achieved in

this simulation by assuming that total

displacement of the Ram was (z =25 mm) in the

z- direction, One load step and a substep value

of 3000 with limits changing between 100 and

4000 have been employed during solution. The

entire model is shown in Fig.(5).

6. Results and Discussion:

Upper bound solution is theoretically

applied for predication of plastic deformation work

(J) for the extrusion of rhomboidal and square

sections from round billets. The numerical

calculations have been successfully performed

concerning the effect of area reduction, die length

- 24 -

and friction factor on the extrusion pressure and the

optimal die length. Through, in this paper, priority

is given to the analysis of the streamlines die

which produces no shear energy at inlet and outlet

of the velocity boundaries, the present method is

applicable to analyze other die profiles simply by

changing the profile function of f(y). The main

advantage of the present work is that it could easily

be applied to the extrusion of many different shapes

just by defining the entry and exit sections functions

and putting them into the general formulations.

Gunasekera and Hoshino [7] carried out similar

work for extruding the polygonal sections from

round billets. It is observed from Fig.(5) and Fig.(6)

that The relative extrusion pressure (PE/o)

decreases with increase in the relative die length

(L/Ro) up to certain optimal relative length and then

it increases. The frictional load has always an

increasing tend with relative die length, while the

deformation load gradually decreases with increase

in the relative die length. Figure (7) shows that the

extrusion pressure increases as diagonal ratio (DR)

degreases.

Fig. 4. Quarter meshed model.

The Von Misses stress and plastic strain contours,

are shown in Figs.(8: A , B ,C and D) for the cases

of DR=1 and DR=0.8 . It can be noted these figures

that the maximum values has been observed at die

exit and billet-die interface. Also it can observe in

these figures that the stresses of extrusion of

rhomboidal section are larger than the stresses of

extrusion of square section.

7. Conclusion:

Upper Bound and FEM Solution is obtained

for the Extrusion of Rhomboidal and Square

Sections from Round Billets through Streamlined

Dies. The effect of area reduction, the optimum

relative die length, the shape of die, frictional

conditions, stress and strain conditions in the die

and billet are also discussed.

Fig. 5. Comparison between the streamlined die

designed by Ref. [7] and authors.

Fig. 6. The effect of friction factor on total relative

extrusion.

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4

Re

lati

ve d

ie p

ress

ure

PE/

o

Relative die length L/Ro

80% Area Reduction,Round to Rhombus extrusion ,=0.12,DR=1

J-frictionJ-deformationJ-total (authors)J-total(Ref.[7])

0

1

2

3

4

5

6

7

0 0.5 1 1.5 2 2.5 3 3.5 4

Rel

ativ

e d

ie p

ress

ure

PE/

o


Round to Rhombus , DR=1 , 40% area reduction

J,=0

J,=0.05

J,=0.1

J,=0.2

J,=0.4

J,=0.6

J,=0.8

J,=1

Billet Die Container

Punch

- 25 -

Fig. 7. The effect of diagonal ratio (DR) on total

relative extrusion pressure.

Fig. 8. A&C: Von Mises stress contours.

B&D:Von Mises plastic strain contours

REFERENCES

1. Laue K, Stenger H. Extrusion: processes,

machinery, tooling. Metals Park, Ohio: American

Society for Metals; (1981).

2. B. Avitzur, Metal Forming: Processes and

Analysis, McGraw-Hill, New York, 1968.

3. C.T.Chen and E.F.Ling, Upper bound solution

to axisymmetric extrusion problems Int. J.Mech.

Sci, Vol.10, PP.863-879(1968).

4. D.Y. Yang C.M. Lee and J.H. Yoon ,Finite

Element Analysis of Extrusion of Section Through

Curved Dies, Int. J. Mech. Sci. Vol.31, No.2, pp.

145-156,(1989)

5. S.K. Lee, D.C. Koo, B.M. Kim, Optimal die

profile design for uni-form microstructure in hot

extrusion, International journal Mach. Tools

Manufacture.Vol. 40 , pp.14571478,(2000).

6. V.Nagpal and T.Altan,Analysis of the three-

dimensional metal flow in extrusion of shapes with

the use of dual stream functions, Proc. 3rd

NAMRC, Canegie-Mellor Univ., Pittsburgh, Pamay

(1975).

7. J.S.Gunasekera and S.Hoshino analysis of

extrusion of polygonal sections through streamlined

dies Journal of Engineering for

Industry,vol.107/229,(1985).

8. Kiuchi M, Kish H, Ishikawa M , Study on Non

symmetric extrusion and drawing, International

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4

Rel

ativ

e d

ie p

ress

ure

PE/

o


40% Area Reduction,Round to Rhombus extrusion ,=0.1

D.R.=0.6

D.R.=0.8

D.R.=1

DR=1

DR=0.8

DR=1

DR=0.8

A

B

C

D

- 26 -

Journal of Machine Tool, Design and Research

conference, 22nd proceedings, p. 52332,(1981).

9. C.M. Lee and D.Y. Yang and K. Lange

Numerical Analysis of Three Dimensional

Extrusion of Elliptic Sections by Method of

Weighted Residuals Int. J. Mech. Sci. Vol.31,

No.5, pp. 379-393,(1989)

10. R. Narayanasamy R. Venkatesan,upper

bound solution to extrusion of circular billet to

circular shape through cosine dies National

Institute of Technology 620 015,(2003).

11. S. Kumar and S.K. Prasad, A Finite Element

Thermal Model for Axisymmetric Cold and Hot

Extrusion using Upper Bound Technique

department of mechanical engineering, institute of

technology ,Banaras Hindu university ,Varanasi

221005,(2004)

12. Guide to the ANSYS Documentation Release

11.0.

Department of Mechanical Engineering,

University of Babylon, Babylon, Iraq.

E-mail: [email protected]

E-mail: [email protected]

14.02.2013 .

- 27 -

file:///C:/Users/User/Downloads/[email protected]:///C:/Users/User/Downloads/[email protected][email protected]

- 28 -


Journal of the Technical University Sofia, branch Plovdiv

Fundamental Sciences and Applications, Vol. 16, 2013

International Conference Engineering, Technologies and Systems

TechSys 2013

BULGARIA

EMPLOYEE-BRAND RELATIONSHIP

RESEARCH IN MACEDONIAN

TELECOMMUNICATION COMPANY

ALEKSANDAR OSMANLI, ATANAS ILIEV

Abstract. The purpose of the study is to examine internal branding in macedonian

telecommunication company as a high technology environment. Theoretical framework is

constructed to measure the current state of case companys employee-brand relationship.

Based on the literature review, a conclusion was made that the concepts of high technology,

internal branding and brand identity are closely connected with each other. Internal branding

is especially important for high-tech companies, because corporate brand is usually their driver

brand and every employee directly or indirectly represents the brand. At the same time, internal

branding is their biggest challenge. Brand identity, on the other hand, provides a basis for

internal branding strategy, but is also the source of brand equity for high technology

companies. Consequently, brand identity is the key concept, providing direction, depth, and

texture for the other branding dimensions.

The empirical study was conducted in a form of a quantitative questionnaire. It was found that

the level of brand knowledge and commitment in the case company was rather good, even

though certain weaknesses were identified. Based on the results, some improvement suggestions

were provided. The empirical results combined to the theoretical foundation can, thus, serve as

a preliminary groundwork for building up an internal brand management strategy for the case

company.

Key words: brands, branding, brand identity, high technology, internal branding, survey

1. Introduction

High technology companies around the

world are facing major challenges. Increasing

global competition, the accelerating pace of

technological development, the consolidation of

markets, and the increased speed with which

imitations turn up on the market have dramatically

shortened product lifecycles. As a result, it is not

enough to have efficient logistic capabilities or

unique production methods anymore; there must be

some completely new ways to make the difference

between company and ones competitors. The initial

concept of competitive advantage is getting

fundamentally new aspects as brands, instead of

products, are becoming the real source of

competitive advantage. [1]

Further, as the importance of brands and

branding is increasing, internal branding has risen

as a number one subject in the field of brand

research as well as business management [2]. So

that companies would be able to sell promises,

instead of mere products, employees should know

what they are doing and, more importantly, why

they are doing. Therefore, before selling the brands

promise to customers, companies need to sell it to

their employees.

The main assumption is that company

personnel should understand the brand meaning and

be committed to implementing it in their everyday

work. Brand in itself is a vast concept and,

therefore, the aim is to concentrate on studying the

most important branding concepts in relation to

high-tech environment as well as to dig into the

process of internal branding. To fully grasp the

issue, the following research objectives have been

set:

1. To discuss the special branding

implications of high technology environment.

- 29 -

2. To identify the characteristics of internal

branding and to define the dimensions concerning

internal branding process.

3. To measure the current state of the case

company's employee-brand relationship and to

evaluate the result in relation to the theoretical

background of the study.

Branding literature has traditionally focused

on the external communication of the brand [3].

Because of this, the internal branding research is

still lacking in clear and commonly accepted

structure, although plenty of different theories about

the subject can be found. Further, the external

branding research has often concentrated on the

branding of consumer products instead of industrial

branding and, as a result, the aspects of high-

technology branding have just recently been

emerging from the branding literature.

As the research problem is clearly

connected with a practical business aspect, the

research should be conducted by adding a practical

viewpoint to the research implementation. This is

why the literature review is supported by an

empirical study collecting and combining internal

branding information in the case company.

2. Internal branding in high technology

environment

The concept of high technology has become

increasingly popular after the boom of information

technology branch in the 1990s but still it lacks a

commonly accepted definition. The general view is

that high technology industries have great

dependence on science and technology innovation

that leads to new or improved products and

services. They often have a substantial economic

impact, fueled both by large research and

development spending and a higher than industry

average sales growth. New product development

and capital investment often go hand in hand,

making high technology companies an attractive

addition to local tax bases. Traditional high-tech

industries include, for example, computer and

information technology, biotechnology, and

telecommunications. During the last five years,

however, technological innovation has created

radical changes in some industries, such as waste

management, agriculture, automotive, and oil and

gas, and these industries are increasingly being

defined as high-tech industries. [4]

One could easily think that in highly

technological markets functionality and features are

what matters, not brands. Why would successful

brand management be so important to high-tech

companies, then? First of all, a strong brand helps

attract and keep customers. Further, it can form a

solid foundation from which to launch new

products, improve relationships with channel

partners, foster good communication among

employees within and across business functions,

and help a company better focus its resources.

Unfortunately, many technology

companies, usually managed by technologists, often

lack any kind of brand strategy and believe that

market success depends primarily on the price-

performance ratio [5]. At the same time, however,

their offerings are becoming commodities

products and services are highly similar and

competitors are fast to catch up the latest

innovations [6]. As a result, in many of the high-

tech markets, financial success is no longer driven

by product innovation alone and marketing skills

and branding are playing an increasingly important

role [6]. Although the lack of managerial interest

and understanding of branding is only one example

of the special characteristics of high-tech

environment, branding high technology is much

more than just promoting the pure product.

High-tech products are sold both in

consumer and industrial markets and the main

feature distinguishing them from traditional

consumer or industrial goods are the short product

life cycles [7]. This means that the products change

rapidly over time and better and renewed versions

come to the markets quickly. The speed and brevity

of these life cycles, caused by continuous

technological advances and research and

development breakthroughs, is the main source of

high-tech branding challenges [5]. Further, the

complexity of the products and the technical

sophistication of the target market often cause

difficulties in managing the relationship with

customers, and companies may find it hard to define

what the actual target market is. Therefore, Figure 1

suggests some specific branding guidelines for

companies operating in high-tech markets to tackle

these challenges.

As discussed earlier, brand awareness

means the extent to which a brand is recognized by

(potential) customers and is correctly associated

with a particular product. Brand image, on the other

hand, is the markets perception of companys

brand identity. For high-tech the importance of

these concepts arise, because customers are

increasingly buying into brands as much as

products, and although price and performance are

essential, they do not guarantee a successful high-

tech venture.

- 30 -


1. Establish brand awareness and a rich brand image.

2. Create corporate credibility associations.

3. Leverage secondary associations of quality.

4. Avoid overbranding products.

5. Selectively introduce new products as new brand and

clearly identify the nature of brand extensions.

Figure 1. Additional guidelines for high-tech

products

One common obstacle, however, is that

establishing positive brand awareness and brand

image requires money and time. High investments

in research and development are typical for high

technology industries [7], which often means that

marketing is running on a low budget. Investments

on branding can make a difference, though: the S

model of customer response to brand awareness

which clearly illustrates that the sales increase

incrementally as branding expenditure and,

therefore, the level of customer awareness increase,

forming an S-shaped curve.

The visibility and presence of the

organization behind a brand can create an image of

size, substance, and competence. This can hold

especially true in high-tech markets because of the

large number of small and medium size enterprises,

global orientation of the companies, and the often

complex nature of the products. The driver brand

for most technology companies is the corporate

brand, not the product brand, meaning that the

importance is on building favorable organizational

associations such as trustworthiness,

innovativeness, expertise, and quality [1]. The

whole organization should be committed to

empowering these associations, but in high-tech

especially the often visible CEO is the key

component performing an important brand-building

and communication function [5].

Customers may find it hard to judge the

quality of high-tech products, mainly because of the

technical sophistication of the products and the

possible lack of user references [1]. Leveraging

every possible positive secondary association may

help to improve the brand reputation and the

perception of product quality and, thus, reduce the

doubts that the customers possibly have. Methods

that are especially suitable in high-tech environment

are getting endorsements from top companies,

leading industry magazines, or industry experts and

gaining visibility by participating in trade shows

and seminars. Nonproduct related associations, such

as sponsorship of events or co-operation with

educational institutes, may prove to be valuable as

well.

To build a strong high-tech brand, managers

need to answer the following questions given on the

so called Brand pyramid. The pyramid consists of

five different levels, each containing strategic

questions regarding the brands tangible and

intangible characteristics (see Figure 2).

Figure 2. Brand pyramid

By answering these questions, from the

bottom to the top, managers of high-tech companies

should be able to form a solid basis for their

branding strategy.

The bottom level of the pyramid represents

the core product the tangible, verifiable product

characteristics. The tendency is moving from selling

just products to selling benefits or solutions,

which is the second level of the pyramid. Even

though this change is a step to the right direction,

the first two levels of the pyramid still represent a

product-centric point of view.

Knowing how the customers feel when

experiencing the tangible characteristics of the

offering and benefits of the brand is a key to true

differentiation and, further, provides direction and

meaning for the brand. The third level of the

pyramid represents the stage when managers

understand the importance of emotional reasons and

act accordingly. Getting to the third level of the

pyramid is already a big achievement for a company

operating in high-tech environment, but a promise-

centric business model is truly accomplished when

a company reaches the fourth and fifth stages of the

pyramid. The top two levels illustrate the idea that

powerful brands attract and hold customers with

their particular promises of value.

The fourth level describes the general

values that the brand reflects, and the fifth level

represents the personality of the brand itself. Brands

that reach the last two levels of the pyramid are,

first of all, able to generate a feasible promise of

value, consisting of functional benefits, emotional

benefits, and price. Second, the most importantly,

they are able to fulfill this promise, which gives

them a huge advantage compared to their

competitors. In short, these last two levels of the

pyramid define the relevant and differentiating

character of the brand.

LEVEL

1

LEVEL 2

What are the tangible, verifiable, objective, measurable

characteristics of products, services, ingredients, or components

that carry this brand name?

What is the

essential nature

and character of

the brand?

What does value mean for

the typical loyal customer?

What psychological rewards or emotional

benefits do customers receive by using this

brands products? How does the customer feel?

What benefits to the customer or solutions results from

the brands features?

LEVEL 3

LEVEL 4

LEVEL 5

- 31 -

The fundamental difference between a

product-centric and a brand-centric company lies in

the attitudes of the people throughout the

organization. Every person in a company should

recognize the brand strategy, be committed to it,

and understand specifically how their behavior

contributes to its execution [5]. This thesis

concentrates on internal matters, but it is important

to note that the brand experience should be

consistent across all the companys partners, as

well. Technology products are often composite

systems consisting of several products or

ingredients, and the partners of a high-tech

company may be responsible for installation,

delivery or support of these products [1]. Therefore,

companies have to ensure that the experience that

customers have with each partner is coordinated and

consistent with the official brand strategy.

A strong corporate brand that will endure

over time is highly depending on the internal

understanding of corporate identity. The biggest

challenge of high-tech branding is to get everyone

in the organization to understand the importance of

branding and what it means to sell promises instead

of just products - internal branding.

Internal branding has been directly linked to

employee satisfaction, which in turn is linked to

customer satisfaction, which is, naturally, linked to

business performance (Drake et al. 2005, 34). For

this thesis, the most significant conclusions of the

theoretical foundation are the following:

1. High-tech brands build equity through a

clear and well-defined brand identity.

2. The biggest challenge of high-tech

branding is to get everyone in the organization to

understand the importance of branding and what it

means to sell promises instead of products.

3. A clearly defined brand identity is the

initial source of internal branding.

4. Getting the employees to know and care

about the brand identity is one of the most

important objectives of internal brand management.

These conclusions clearly show that the

concepts of high technology, internal branding and

brand identity are connected with each other; Figure

3 present the most relevant linkages and

relationships between these three concepts. Internal

branding is especially important for high-tech

companies because corporate brand is usually their

driver brand and every employee directly or

indirectly represents the brand. At the same time,

internal branding is their biggest challenge. Brand

identity, on the other hand, provides a basis for

internal branding strategy, but is also the source of

brand equity for high technology companies.

Consequently, brand identity is the key concept of

this thesis, providing direction, depth, and texture

for the other branding dimensions.

Figure 3. Brand identity, high-tech branding and

internal branding relationships

By studying employee perceptions of brand

identity, it should be possible to assess the strengths

and weaknesses of the current state of employee-

brand relationship and whether there is a need for

better brand identity management.

3. Research process and data collection

The case company is leading macedonian

carrier of electronic communications, which offers

to its customers a wide array of top excellence

telecommunication services and amusing contents

within the scope of the fixed network, broadband

services and integrated solutions, also including TV

over Internet Protocol (IPTV). The Companys

product portfolio includes Internet Protocol based

services, data transfer, sale and lease of equipment

and services for system integration. The company

currently consists of eight different departments.

This thesis bases on deductive research approach,

which involves the development of a theory that is

subjected to a rigorous test. The study is executed

according to a holistic case-study strategy, which

also employs characteristics of survey strategy in

the form of a questionnaire. It is consisted from a 22

items in two main sections (Table 2).

The first section of the questionnaire,

questions from 1 to 12, measures whether the

employees know what their brand stands for, and

the second section, questions from 13 to 22,

measures whether they care. The measurement scale

used in the sections was a five-point Likert scale

reflecting agreement in the 1st section and

importance in the 2nd

section. In the 1st section, the

higher the level of agreement is, the better the

employees know: number 1 to the outcome of

strongly disagree, 2 to disagree, 3 to neither

agree nor disagree, 4 to agree and, finally, 5 to

strongly agree. In the 2nd

section, the higher the

level of importance is, the more the employees care:

number 1 to the outcome of unimportant, 2 to

less important, 3 to neither unimportant nor

important, 4 to important and, finally, 5 to very

important.

The biggest

challenge

R

e

l

a

t

i

o

n

s

h

i

p

Reflection

Personality Physique

Self-image

C

u

l

t

u

r

e

BRAND IDENTITY

Source of

brand

equity

Fondation

for strategy

HIGH-TECH

BRANDING

INTERNAL

BRANDING

- 32 -


Questions from 1, 2, 3, 4, 13 and 14 reflect

culture, questions 5, 6, 15 and 16 reflect personality,

questions 7, 8, 17 and 18 reflect physique, questions

9, 10, 19 and 20 reflect relationship, questions 11

and 21 reflect reflection, and, finally, questions 12

and 22 reflect self-image. Further, questions 5, 6, 7,

8, 15, 16, 17 and 18 represent issues related to the

company itself, whereas questions 11, 12, 21 and 22

reflect issues related to customers.

In order to reduce the possibility of getting

biased, misleading or wrong research results, it is

necessary to pay attention to two particular

emphases on research design reliability and

validity [8]. Both terms signify trustworthiness;

reliability tests how consistently a measuring

instrument measures whatever concept it is

measuring, whereas validity tests how well an

instrument that is developed measures the particular

concept it is supposed to measure.

A total amount of 574 responses was

received from the employees. The largest groups of

respondents were obviously from sales and service

departments, while finance, IT and marketing

departments were represented with smaller groups

of respondents (Table 1).

Table 1

Respondents according to departments

Department Number of

Respondents %

Sales 224 39.0%

Marketing 14 2.4%

Services 182 31.7%

IT 56 9.8%

Finance 98 17.1%

Total: 574 100.0%

Table 3 presents a summary of the research

results according the chosen level of agreement and

importance for every different question.

From the questions considering the culture

of the brand, there is high level of agreement and

importance, expect for Q2 considering the clear

understanding of the company's vision most of the

responders neither disagree nor agree.

The highest levels of agreement and

importance were noticed on every question

considering the brand personality. The same results

are received on the remaining groups of questions

considering physique, relationship, reflection and

self-image of the brand. Only the responses on Q7

shows that responders generally neither disagree nor

agree with this issue.

Table 2

Questionnaire

Section 1: Please indicate your level of agreement with

each of the following statements

(1 - stongly disagree, 5 - strongly agree)

Agreement

1

I have clear understanding of what the company mission

is

2 I have clear understanding of what the company vision

is

3 I have clear understanding of what the company values

is

4 Mission, vision and values of my company are reflected

in my everyday work

5 I understand how my company wants to be seen by

customers, competitors and media

6 I know what makes my company different from its competitors

7 I know what customer needs my company is fulfilling

with its products and services

8

I think that my company transmits a constant visual

image through its facilities, advertising and communication material

9 I know what I, as an employee, have to do in order to

deliver on my company's product promise

10 I know what I, as an employee, have to do in order to satisfy customers' needs and expectations

11 I have a clear idea of how the customers feel about my

company's products and services

12 I know what my company's customers are like

Section 2: Please indicate your level of importance with

each of the following statements (1 - unimportant, 5 - very

important)

Importance

13

A common, company-wide understanding of the

company mission, vision and values

14 Implementing the company mission, vision and values

in my everyday work

15 Other people's opinion of my company

16 Superiority of my company compared to its competitors

17 The offer of products and services of my company

18 A constant visual implementation of the company

facilities, advertising and communication material

19 Company's expectations of me as an employee

20 Customer's expectations of me as an employee

21 Customer perceptions of and attitudes towards the

company

22 Knowing who customers are

23

Circle your department:

Sales

Marketing Services

IT

Finance

- 33 -

Table 3

Summary of research results according the level of

agreement and importance

AGREEMENT 1 2 3 4 5

Q1

Culture 0 74 148 222 130

Q2

Culture 0 116 176 120 162

Q3

Culture 0 42 176 180 176

Q4

Culture 0 28 120 236 190

Q5

Personality 0 14 46 152 362

Q6


Q7

Physique 112 28 180 162 92

Q8

Physique 0 172 0 116 286

Q9

Relationship 0 0 0 106 468

Q10


Q11

Reflection 0 0 46 74 454

Q12

Self-image 0 0 46 130 398

IMPORTANCE 1 2 3 4 5

Q13

Culture 0 14 96 138 326

Q14

Culture 0 14 64 183 312

Q15


Q16


Q17

Physique 0 0 60 78 436

Q18

Physique 0 32 14 92 436

Q19


Q20


Q21

Reflection 0 0 14 88 472

Q22

Self-image 0 14 78 74 408

4. Conclusions

The level of brand knowledge and

commitment in the macedonian telecommunication

company was very good, even though some

weaknesses were identified company's vision and

fulfilling customer needs with products and

services.

References

1. Sawhney, M. 2005. Branding in Technology

Markets. Chapter 11 in Kellogg on Branding: The

Marketing Faculty of the Kellogg School of

Management. Eds. Tybout, A., Calkins, T. New

Jersey: Jon Wiley & Sons.

2. Davis, S. 2005. Building a Brand-Driven

Organization. Chapter 12 in Kellogg on Branding:

The Marketing Faculty of the Kellogg School of

Management. Eds. Tybout, A.,

Documents

ISSN 1310-8271 том 19, книга 2, 2013 Volume 19, Book 2, 2013