“A STUDY REPORT ON STAR RATING OF AN AIR CONDITIONER”
An Industry Oriented Mini Project Report Submitted to
Jawaharlal Nehru Technological University, Hyderabad
In partial fulfillment of the requirementsfor the award of the degree of
BACHELOR OF TECHNOLOGY
IN
MECHANICAL ENGINEERING
ByB. MOUNIKA REDDY C. RAJ SEKHAR(09881A0310) (09881A0321)
N.SINDHU K.SRIKANTH(09881A0338) (09881A0339)
Under the guidance ofMr. N.SRINIVASA REDDY(Ph.D)
Associate Professor Department of Mechanical Engineering
DEPARTMENT OF MECHANICAL ENGINEERING
VARDHAMAN COLLEGE OF ENGINEERING(Autonomous)
(Affiliated to JNTU Hyderabad, Approved by AICTE and Accredited by NBA)Shamshabad – 501 218, Hyderabad
2012 – 2013
VARDHAMAN COLLEGE OF ENGINEERING(Autonomous)
(Affiliated to JNTU Hyderabad, Approved by AICTE and Accredited by NBA)Shamshabad – 501 218, Hyderabad
DEPARTMENT OF MECHANICAL ENGINEERING
CertificateThis is to certify that an Industry oriented mini project
work entitled ” A Study Report on Star Rating of an Air
Conditioner” is the bonafide work done By
B. MOUNIKA REDDY C. RAJ SEKHAR(09881A0310) (09881A0321)
N.SINDHU K.SRIKANTH(09881A0338) (09881A0339)
at Tecumseh Products India Private Limited, Hyderabad. is submitted to Jawaharlal Nehru Technological University, Hyderabad in partial fulfillment of the requirements for the award of B.Tech degree in Mechanical Engineering during 2012-2013.
Project Guide: Head of the Department:
Prof. N. SRINIVASA REDDY Prof. N. SRINIVASA REDDYAssociate Professor Dept of Mechanical Engineering,Dept. of Mechanical Engineering Vardhaman College of Engineering,Vardhaman College of Engineering, Hyderabad.Hyderabad.
Viva-Voce held on……………………………………………
_________________ _____________________ Internal Examiner External Examiner
DECLARATION
We hereby declare that this project report titled “A Study Report on Star Rating of
an Air Conditioner” is a genuine project work and effort carried out by us in B.Tech
(Mechanical Engineering) degree course of Jawaharlal Nehru Technology University, Hyderabad
and has not been submitted to any other course or university for the award of our degree. Where
other sources of information have been used, they have been acknowledged
Signature of the Candidate
B. MOUNIKA REDDY (09881A0310)
C. RAJ SEKHAR (09881A0321)
N.SINDHU (09881A0338)
K.SRIKANTH (09881A0339)
ACKNOWLEDGEMENT
The satisfaction that accompanies the successful completion of the task would be put
incomplete without the mention of the people who made it possible, whose constant guidance and
encouragement crown all the efforts with success.
We avail this opportunity to express our deep sense of gratitude and hearty thanks to
Mr. Aditya Vishwanathan for granting us this great opportunity to do our project in this
esteemed research facility Tecumseh Products India Pvt. Ltd. despite their own schedule
constraints.
It was impossible for us to do our project outside our college campus if our beloved
principal has not granted us the permission. We, thereby express our deep sense of gratitude and
thanks to Dr. N. Sambasiva Rao, Principal, Vardhaman College of Engineering.
We would also like to express sincere thanks to Prof. N.Srinivasa Reddy, Head,
Department of Mechanical Engineering, for his expert guidance and encouragement at various
levels of our Project.
We are thankful to our guide ___________ , Assistant Professor, for his sustained
inspiring Guidance and cooperation throughout the process of this project. His wise counsel and
suggestions were invaluable.
We cannot forget to recall, with our deepest regards, the power of blessings of our parents,
and friends which gave us the courage and confidence to materialize our dream of completing this
project.
B. MOUNIKA REDDY (09881A0310)
C. RAJ SEKHAR (09881A0321)
N.SINDHU (09881A0338)
K.SRIKANTH (09881A0339)
TABLE OF CONTENTS
Candidates Declaration i
Acknowledgement ii
Abstract iii
Nomenclature iv
List of Figures vi
List of Tables vii
List of Plots viii
Table of Contents ix
CH.NO. NAME OF THE CHAPTER PAGE NO
1. Introduction 1
2. Literature Survey 3
2.1 Aerodynamic effects of wing leading edge ice contamination 3
2.2 Leading edge bluntness effects on aerodynamic heating and
drag of power law body in low density hypersonic flow 5
3. Wind Tunnel 6
3.1 Types of wind tunnel 7
3.1.1 Open circuit subsonic wind tunnel 7
3.1.2 Closed circuit subsonic wind tunnel 8
3.2 Components of wind tunnel & their functions 9
3.3 Features and capabilities of HAL wind tunnel 10
3.4 Instrumentation 11
3.5 Wind tunnel balance
11
3.6 Wind generation system 12
3.7 Model support system
12
3.8 Transducer – strain gauge type balance 13
3.9 Signal conditioning amplifier
13
3.10 Analog to digital converters
13
3.11 Data processing computer connected to ADC 13
3.12 Data acquisition system 14
4. Models and their Design, Material & Fabrication 15
5. Boundary layer and Sensitiveness of leading edge 18
5.1 Boundary Layer 18
5.1.1 Boundary layer control
18
5.1.2 Methods of Boundary layer control
19
5.2 Sensitiveness of Leading Edge 19
6. Testing 21
7. Results and Discussions 22
8. Conclusion and Future Scope 25
9. Bibliography 26
INTRODUCTION
Right from the “Flyer-I” to the latest state-of-the-art airplanes, rotorcrafts, missiles, space
launch vehicles and other innovative aircrafts WIND TUNNELS are being used to solve the
basic aerodynamic problems. Testing newly designed aircraft in appropriate real-time weather
conditions are needed in order to properly asses its capabilities during real time flying, which is
achieved in a most accurate, rapid and economical way by using wind tunnels.
The quantum leap in computer technology in the 20th century has led to the development
of techniques such as CFD, CFX and other hi-tech simulation software for the analysis of
aerodynamic problems and generation of useful data for the design and development of
aircrafts, but still wind tunnels are considered as the most reliable source for gathering required
data and information necessary for the design of an aircraft. Hence wind tunnels need to be
calibrated to achieve this reliability.
The Wright Brothers built a wind tunnel, first a simple one and then a large and a more
sophisticated tunnel with 16x16 sq. in a test section which was successful with the addition of
rudder to counteract the adverse yaw from the wrapped wing roll control. The value of wind
tunnel in aerodynamic design was conclusively demonstrated in 1903. It is a research tool used
in aerodynamic research to study the effects of air moving past solid objects.
Wind tunnels are often the most rapid, economical and accurate means for conducting
aerodynamic research and obtaining aerodynamic data to support design decisions. The
aerodynamic characteristics of an aircraft is achieved by the force and moment measurements
using a six component strain gauge balance and the quality of these forces and moments
mainly depend on the quality of flow in test-section, instrumentation and model design and
consideration. The test section flow condition can be qualitatively seen by tufting the entire test
section and observe fluctuations or disturbances.
Aerodynamicists use wind tunnel to test the models of proposed aircrafts and engine
components. The main aerodynamic objective for most wind tunnels is to obtain a flow in the
test section that is as near as possible to a parallel steady flow with uniform speed through out
the test section. During the test, the model is placed in the test section of tunnel and air is made
to flow past the model
LITERATURE SURVEY
2.1 AERODYNAMIC EFFECTS OF WING LEADING EDGE ICE
CONTAMINATION:
The cleanliness of leading edge is very important factor for an aircraft and has a great
impact on its performance. The most significant effect of snow or ice on the wing surface is its
influence on the smooth flow of air over the surface contour. Changes in the contour shape and
roughness of the surface will cause the airflow to begin to separate from the wing at lower angle of
attack than normal and cause a reduction in the lift which will normally be developed by a wing at
a given angle of attack and a given airspeed. Both the maximum lift, which can be developed, and
the angle of attack at which it will be developed will be reduced significantly. Stall buffet and stall
will be encountered at higher than normal airspeeds.
LIFT AND DRAG EFFECTS OF WING CONTAMINATION:
Ice contamination of an aircraft wing also has a significant detrimental effect on the
aircraft’s total drag, that is, the force that resists the aircraft’s forward motion through the air. The
total drag has two components, parasite drag and induced drag. Induced drag is that drag which is
produced by the generation of the lift. Induced drag increases as the angle of attack increases.
Therefore, since a contaminated wing must fly at higher angle of attack at a given airspeed will be
higher than the induced drag of an uncontaminated wing. Furthermore, since ice contamination
causes the airflow to separate earlier from the upper surface of the wing, its results in a higher
induced drag value at any angle of attack. The increase in parasite drag as a result of ice
contamination is small in comparison to the increase in induced drag.
The leading edge portion of the wing is most sensitive to contamination. The effects of the
contamination decrease as the forward most extent of the contamination moves farther aft of the
leading edge. Glaze ice accretions, which occur at temperatures just below freezing, provide the
largest aerodynamic penalty.
Ice accumulation, in particular, the detrimental effects on lift and drag associated with wing
surface roughness has been identified as a casual factor in a number of take-off accidents involving
jet transport aircraft.
EFFECTS OF ICING ON ROLL CONTROL:
Ice on the wings forward of the ailerons can affect roll control. Wings on general aviation
aircraft are designed so that stall starts near the root of the wing and progresses outward, so the
stall does not interfere with roll control of the ailerons. However, the tips are usually thinner than
the rest of the wing, so they are the part of the wing that most efficiently collects ice. This can lead
to a partial stall of the wings at the tips, which can affect the ailerons and thus roll control. If ice
accumulates in a ridge aft of the boots but forward of the ailerons, this can affect the airflow and
interfere with proper functioning of the ailerons. If aileron function is impaired due to ice, slight
forward pressure on the elevator may help to reattach airflow to the aileron.
WING STALL:
The wing will ordinarily stall at a lower angle of attack, and thus a higher airspeed, when
contaminated with ice. Even small amounts of ice will have an effect, and if the ice is rough, it can
be a large effect. Thus an increase in approach speed is advisable if ice remains on the wings. How
much of an increase depends on both the aircraft type and amount of ice. Stall characteristics of an
aircraft with ice-contaminated wings will be degraded, and serious roll control problems are not
unusual. The ice accretion may be asymmetric between the two wings. Also, the outer part of a
wing, which is ordinarily thinner and thus a better collector
of ice, may stall first rather than last. [7]
2.2 LEADING EDGE BLUNTNESS EFFECTS ON AERODYNAMIC
HEATING AND DRAG OF POWER LAW BODY IN LOW DENSITY
HYPERSONIC FLOW
A numerical study is reported on power law shaped leading edge situated in a rear field
hypersonic flow. The sensitivity of the heat flux and drag coefficient to the shape variation of such
leading edge is calculated. Calculations shows that the stagnation point heating on power law
leading edge with finite radius of curvature follows the same relation for classical blunt body in
continuous flow. It scales inversely with the square root of the curvature radius at the nose. Those
leading edge with zero or infinity radii of curvature, the heat transfer behavior is in surprising
agreement with that for classical blunt body far from the nose of leading edge. [8]
REFERENCES
1. HAL- ARDC Wind Tunnel reference material.
2. Canadian Aviation Safety Board, Majority report.
3. W. F. N. SANTOS JOURNAL, Combustion and Propulsion Laboratory,
National Institute for Space Research
4. ALAN POPE, WILLIAM H. RAE, Jr and JEWEL B. BARLOW:
“LOW SPEED WIND TUNNEL TESTING” Third ed., John Wiley and sons Inc.
New York-USA.
5. JOHN D. ANDERSON, Jr (2007) : “FUNDAMENTALS OFAERODYNAMICS” Fourth
ed., Mc Graw-Hill Inc. Singapore.
6. L. J. CLANCY (1975) : “AERODYNAMICS” First ed., Pitman Publishing Corporation.
7. A C KERMODE: “MECHANICS OF FLIGHT” Eighth ed., New Delhi
8. http://windtunnelengr.ucdavis.edu/research
UC DAVIS AERONAUTICAL WIND TUNNEL FACILITY,
UNIVERSITY OF CALIFORNIA, CALIFORNIA, USA.