LABORATORY OUTCOME BASED ASSESSMENT GUIDELINE

TOPIC EXPERIMENT: FLUID FRICTION TEST

PROGRAM LEARNING OUTCOMES (PLO)

Upon completion of this course, students should be able to: 1. Apply knowledge of mathematics, science and engineering fundamentals to well defined civil engineering theories

and procedures. 2. Use necessary skills and technique to conduct experiment and civil engineering practices 3. Communicate effectively both in written and spoken form with other collegue and community. 4. Provide effective solution to civil engineering problems. 5. Develop social responsibilities and humanistics values 6. Recognise the need and to engage in, lifelong learning and professional development. 7. Apply entrepreneurship skill for career development. 8. Adhere to professional codes of ethics to adapt in working environment. 9. Demonstrate effective leaderships skills and team work responsibilities.

COURSE LEARNING OUTCOMES (CLO)

Upon completion of this course, students should be able to:- 1. Explain clearly the fluid characteristics, fluid pressure and solve problems in flow of fluid using Bernoulli’s

Equation(C4) 2. Apply principles to solve problems in laminar and turbulent flow and relation to Reynolds number, Darcy’s and

Hagen-Poiseuille equation for problem solving (C3) 3. Apply appropriate knowledge in minor loss in pipe and uniform flow in open channel (C3) 4. Conduct correctly methods and procedures of hydraulics solution towards practical problems (P2) 5. Demonstrate positive team working attributes by contributing actively in group for laboratory tests that yield valid

results (A3)

No. Lab.Title Teaching Method

PLO CLO GSA / LD

1.0 Fluid Characteristics

Practical

2 & 9

4 & 5

LD 2 & LD 9

2.0 Bernoulli Theorem

3.0 Reynolds Number

4.0 Fluid Friction Test

5.0 Uniform Flow Generic Student Attributes (GSA): GSA 1 Communications Skills GSA 2 Critical Thinking and Problem

Solving Skills GSA 3 Teamwork Skills GSA 4 Moral and Professional Ethics GSA 5 Leadership Skills GSA 6 Information Management Skills and

Continuous Learning GSA 7 Entrepreneurship Skills

Learning Domain (LD): LD 1 Knowledge LD 2 Practical Skills LD 3 Communicatio Skills LD 4 Critical Thinking and Problem

Solving skills LD 5 Social Skills and Resposibilities LD 6 Continious Learning and

Information Management Skills LD 7 Menagement and Entepreneurial

Skills LD 8 Professioalism , Ethics and

Moral LD 9 Leadership and Teamwork Skiils

EXPERIMENT : 4

TOPIC EXPERIMENT : FLUID FRICTION TEST

OBJECTIVE : 1. Investigation of pressure losses in pipes

2. Influence of flow speed on pressure loss

3. Comparison of calculated and experimental values

APPARATUS : Hydraulic bench

Fluid Friction Test Apparatus

Stop Watch

Figure 1: Fluid Friction Apparatus

1- Shut-off valves for individual measuring

sections

2 - Double pressure gauge with connecting

hoses

3 - Infeed (covered)

4 - Steel tube support

5 - Measuring objects for flow

measurement

6 - Connections for measuring points

7 - Pressure tapping nipple

8 - Drain

9 - Measuring objects for shut-off devices

THEORY : Experimental conditions

With turbulent pipe flow, where the flow is considered steady at Reynolds’ numbers of

Re > 2320, pressure loss is proportional to the

- length, l of the pipe

- Coefficient of pipe friction λ

- Density, ρ of flowing medium

- Square of the flow speed, v.

In addition, the pressure loss increases as the pipe diameter reduces. It is calculated as

follows:

The associated head loss hv is calculated as follows:

For turbulent pipe flow (Re> 2320) the pipe friction coefficient λ depends on the pipe

roughness k and the Reynolds’ number Re. The pipe roughness k specifies the height of

the wall elevations in mm.

The relationship between Re, λ and k is shown in the Colebrook and Nikuradse diagram.

Here, the wall roughness k is related to the pipe diameter d. The Reynolds’ number Re is

calculated from the pipe diameter d, flow speed v and kinematic viscosity ν The

Reynolds’ number Re is calculated from the pipe diameter d, flow speed v and kinematic

viscosity.

The kinematic viscosity for water can be taken from the table as a function of the

temperature. The flow speed v is calculated from the volumetric flow V and the pipe

cross-section.

For hydraulically smooth pipes (Re < 65 d/k) and a Reynolds’ number in the range of

2320< Re < 105, the pipe friction coefficient is determined using the Blasius formula

For pipes in the transition range to rough pipes (65 d/k <Re < 1300 d/k, the range below

the limit curve in the diagram) the pipe friction coefficient is calculated according to

Colebrook

It is an implicit formula that has to be iteratively resolved. First of all estimate λ, place it in

the formula and calculate an initial approximation. This approximation is re-used in the

equation to calculatea second approximation.

If the estimated value is taken from the Colebrook and Nikuradse diagram, the initial

approximation is generally sufficiently accurate and the values only differ after the 3rd

decimal place. Table 1 Kinematic viscosity of water as a function of temperature (after

Kalide: Technische Strömungslehre [Technical Fluid Mechanics]).

Table 1: Kinematic Viscosity

Experimental method

In the following experiment, the pipe is investigated in measuring section II. The

measuring length is l = 800 mm. The series of measurements is carried out based

on the head loss hv, i.e. the ball cock before the measuring section is used to set certain

heights on the pressure gauge and determine the relevant volumetric flow. The pressure

gauge is connected and the measurements are carried out as described in section 2.

PROCEDURES: 1. Set up the HM 150 Basic Hydraulics Module experimental unit, with the drain above

the volumetric tank.

2. Unscrew rear star handle nuts for pressure gauge mounting and move pressure

gauge down one hole, tighten star handle nuts again.

3. Set up hose connections between HM 150 and the unit.

4. Open HM 150 drain.

5. Switch on the pump and slowly open the main valve on the HM 150.

6. Connect pressure gauge to the desired measuring points.

7. Slowly open ball cock before the desired measuring section and vent the pressure

gauge (see section 2.1) Dual pressure gauge.

8. By simultaneously adjusting the vent and drain valves on the pressure gauge, regulate

the water level such that both water columns are in the measuring range.

9. Determine the volumetric flow. To do this, stop for the time t required to top up the

volumetric tank on theHM150 from 10 to 20 or 30 liters. The drain valve below the

tank must be closed.

RESULTS:

Measuring section II PVC pipe 20x1.5

Measured head loss hvm ( m )

Volumetric flow ( liter )

Time (sec)

Flow rate, Q (m3/s)

Flow speed/velocity (m/s)

Reynolds’ number Re

Pipe friction coefficient according to Blasius, λ

Calculated head loss, hvT

Variance ( %)

QUESTIONS: 1. What conclusions can you draw from the data obtained? 2. What further assertions can you make after evaluating the diagram? 3. Plot the graph Head loss versus Flow rate.