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Design and Fabrication of Wind Tunnel.

Dept of Mechanical Engineering, BMIT, Solapur. Page 1

CHAPTER NO: 1

INTRODUCTION


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1.1 Introduction

A wind tunnel is an equipment designed to generate air flows of various speed

and to visualize flow patterns on object under test. Wind tunnel is design to perform

various tests on and get the information about the performance of aerodynamically

shaped object. Wind tunnel is design for specific purpose with speed range. Wind tunnels

are typically used in aerodynamic research to analyze the behavior of flows and effect of

air resistance under varying conditions, both within channels and over solid surfaces. In

wind tunnel we use the controlled environment (i.e. speed and flow) to measure flow

pattern and forces on proposed models as they are being designed. Being able to collect

diagnostic information from models allows engineers to inexpensively tweak designs for

aerodynamic performance without building numerous fully-functional prototypes. In thecase of this project, the wind tunnel will serve as an educational and research tool to

analyze basic flow principles.

The students required to apply the theoretically developed engineering concepts to

overcome the practical problems, wind tunnel is useful for conceptualization of flow

pattern and determination of drag and lift .In this process we have an opportunity to test

the concepts by carefully designed experimental set up and various tests were carried out

by appropriate facilities. While the observing wind tunnel operation the students will becapable for understanding of practical situations and remedies over it. The best solution is

to ensure that the experimental facilities are adequate enough to test and verify basic

concepts in fluid dynamics so that the learning experience of the student leads to a good

foundation on which they build a successful engineering career.

A wind tunnel means concept of venturi for using this concept we designed the

only venturi on this we are concentrated.


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1.2 Definition of Problem:

It is difficult to understanding aerodynamics theoretically only. With only theoretical knowledge and principles it is difficult to understand actual

concepts, we require some equipment to visualized and understand the actual real

life problems.

There is no such equipments or facility available in institutes campus or innearby institute for practical demonstration of flow patterns over aerofoil shapes.

Establishing facilities like CFD softwares at the teaching institution is oftenexpensive as far as knowledge expertise and service is concerned.

Required to carry out flow visualization for demonstrations purpose and aworking knowledge of the basic flow patterns is the need of an hour for any

engineering student.


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CHAPTER NO: 2

LITERATURE REVIEW


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2.Literature Review:

Wind engineering is a field that has been evolving over centuries. The first step in

wind engineering was over 350 years ago when Torricelli invented the barometer to

measure air pressure (Cochran 4). There have been many changes over the years, but at

its core wind engineering is based on using measurements of actual wind flows to predict

the forces transferred to engineered structures and machines

At the end of 1901, the Wrights brother was frustrated by the flight test of their

1900 and 1901 gliders. The airfoils were flown frequently up to 300 feet in single glide.

In 1901 Wright brother built a wind tunnel to test their aero plane wings & Tuft

baal wind tunnel to suited classroom environment.

The Baals wind tunnel, designed by NASA Engineer Donald D. Baals, is a 4-foot

long open loop or suction wind tunnel.The Baals wind tunnel is used for this projectbecause it is simple, easy to build and operate, and is ideally suited to the classroom

environment.

Fig 1: Baals wind tunnel

A wind tunnel is a device used to producing a moving air stream for experimental

purposed. The Stevenson (1969) stated that the main purpose of wind tunnel is to provide

a uniform and turbulent free stream of air.


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Anderson (1989) stated that wind tunnel is ground based experimental facilities

designed to produce flows of air that simulate natural flows occurring outside the

laboratory.

Konstantin Tsiolkovsky also experimented with the study of fluid movement, in

1992. He developed prototypes of wind tunnels that he used to study and measure

aerodynamics concepts. His contributions helped lead to the understanding of

aerodynamics employed by race car drivers, pilots and engineers today.

In 1998, Mike Fitzgerald built a wind tunnel in small size to education purpose

Roberts (2001) describes hydrodynamics as the study of how fluids and gases

move around an object. He further states that the study of hydrodynamics is important in

that fluid movements help determine the shape and function of many vehicles.

.


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CHAPTER NO: 3

THEORY


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3.1 Definition of A Wind Tunnel:-

A wind tunnel is a specially designed and protected space into which air is drawn,

or blown, by mechanical means in order to achieve a specified speed and predetermined

flow pattern at a given instant. The flow so achieved can be observed from outside the

wind tunnel through transparent windows that enclose the test section and flow

characteristics are measurable using specialized instruments. An object, such as a model,

or some full-scale engineering structure, typically a vehicle, or part of it, can be

immersed into the established flow, thereby disturbing it.

The objectives of the immersion include being able to simulate, visualize, observe

or measure how the flow around the immersed object affects the immersed object.

3.2 Scope of study:

We designed wind tunnel on the basis of principle of venturi so we concentrated

on the venturi design as wind tunnel. We designed the part of venturi i.e. conversion,

diversion and throat. We considered throat as test section and did the calculations.


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3.3 Types of Wind Tunnel

The main types of wind tunnel are,

Low Speed Wind Tunnel & High Speed Wind Tunnel.

Low Speed Wind Tunnel

Open loop wind tunnel Close loop wind tunnel Subsonic wind tunnel (neglecting effect of compressibility ) Transonic(considering effect of compressibility ) Supersonic or hypersonic(consider effect of compressibility with nitrogen or

helium as working fluid)

Wind tunnel using water stream(in case of Boats and submarines) Icing tunnels (including refrigeration devices to cool air in tunnel and water spry

devices to provide liquid droplets in test section).

Both (open & close) designs have their own advantages and disadvantages. The

open system has a much lower capital investment, but requires larger more powerful fans.

The closed loop system requires a larger capital investment, but uses less powerful fans

because the loop maintains the net circuit pressure.

Subsonic or low-speed wind-tunnels are the most common type and the wind

tunnel described in this paper is of this type. Transonic wind-tunnels are common in the

aircraft industry since most commercial aircraft operate in this regime. Supersonic wind-

tunnels can be used to investigate the behavior of jet engines and military aircraft.

Hypersonic wind-tunnels find their applications in rockets and space vehicles.

A further way to categorize low-speed tunnels is by dividing them into open

circuit or closed circuit wind-tunnels. In open circuit wind-tunnels there is no use forcorners and long diffusers but the power needed to drive the wind-tunnel is high because

of the loss of energy in the out- flowing air. Closed circuit wind-tunnels reticulate the air

and thus normally need less power to achieve a given flow speed.


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3.4 Main Parts of Wind Tunnel:

The main components of the proposed wind tunnel in order from intake to outlet

are the axial fan, contraction,Honey comb section, test section and Diverging part. All

these details are shown in layout with dimensions for this project in Figure 9.

Fan:

There are many different fans that can be used in the wind tunnel to achieve the

required dimensional similarity. Electric axial fans were selected for their low cost and

efficiency in producing high wind velocities.

The cost of the added flow conditioning for the axial fan is much less than the cost

of blowers, which produce a more uniform velocity distribution. Axial fan speeds can be

adjusted by using the dimmer.

The axial fans selected are electric driven. These electric fans have the advantage

less fluctuations, lower operating costs, and have shown to be more reliable in practice.

The fan is used to create the flow. At the back side of fan smoke is generated, this

smoke is sucked by air and pass through convergent, Test and divergent sections of wind

tunnel. We can adjust the speed of air flow by dimmer.

Specification

Diameter: 420mm

Motor hp: hp

Speed: 0 to 2800 rpm

Converging part:

This is 1st

part of wind tunnel, in this the pressure drop takes place and velocity of

air increases. This air passed through the honeycomb section to get stream lines of air. Inthis we get turbulent flow so we use honey comb section after this, velocity of air

increases in this part.


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Honey comb section:

It is very essential for the testing purpose. It create different flow pattern. This

used to create laminar stream lines to pass over the model. Due to honey comb we can

see flow visualization on the model because of the clear stream lines.

Test section:

Test section is to visualize the air flow, effect of air on the model, angle of attack,

eddies formation on the model. By this we can observe the flow over the model. This is

made up of glass for transparency purpose.

The test section size was limited to minimize the fan size required the larger the

test section the larger and more powerful the fans required to create the same mean wind

speed. For the final design turntables will be used in the test section to change the

directionality of the prevailing wind on the test models.

Diverging part:

After passing flow over the model, air speed is decreased again in the diverging

part.

The wind tunnel diffuser section is used to reduce the wind speed velocity while

minimizing losses using a diffuser before the settling chamber decreases the speed of the

air flow for screens and flow strengtheners, thus minimizing the power losses because the

power losses through the wind tunnel are related to the speed of the fluid cubed.

For this wind tunnel design an equivalent conical expansion angle of six degrees

was chosen along with an area ratio of 2:1.

The most wind tunnel designs the most efficient expansion angle is five degrees.


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3.5 Theory

3.5.1 Venturi:-

The first test object created was a venturi. A venturi is defined as a short tube with

a constricted throat that is used to determine fluid pressures and velocities by

measurement of the differential pressures generated at the throat, as fluid traverses the

tube. The venturi was chosen as the first test object because it could be used to verify that

accurate data could be obtained from the tunnel. If the readings obtained from the tunnel

closely matched theoretical calculations, verification, that the wind tunnel and

instrumentation were functioning properly, would be obtained.

3.5.2 Laminar Flow

In laminar flow the motion of the particles of air is very orderly with all particles

moving in straight lines parallel to the flow direction.

Fig 2: Laminar Flow

Laminar flow (or streamline flow) occurs when air flows in parallel layers, with

no disruption between the layers. At low velocities the air tends to flow without lateral

mixing, and adjacent layers slide past one another like playing cards. There are no cross

currents perpendicular to the direction of flow, nor eddies or swirls of air. In laminar flow

the motion of the particles of air is very orderly with all particles moving in straight lines

parallel to the flow direction. In fluid dynamics, laminar flow is a flow regime

characterized by high momentum diffusion and low momentum convection.


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When a air is flowing through a closed channel such as a pipe or between two flat

plates, either of two types of flow may occur depending on the velocity of the fluid:

laminar flow or turbulent flow. Laminar flow tends to occur at lower velocities, below the

onset of turbulent flow. Turbulent flow is a less orderly flow regime that is characterized

by eddies or small packets of air fluid particles which result in lateral mixing. In

nonscientific terms laminar flow is "smooth", while turbulent flow is "rough".

3.5.3 Turbulent flow

In turbulent flow vortices, eddies and wakes make the flow unpredictable.

Turbulent flow happens in general at high flow rates.

Turbulent is Opposite of laminar, where considerable mixing occurs,

velocities are high.

Fig 3: Turbulent Flow

Turbulent flow (also called turbulence) is airflow resulting from the breakup of

laminar flow, resulting in tumbling, swirling or violently agitated motion. In a wind

tunnel using the vapor tracks, turbulence shows up when the smoke swirls or dissipates.

Turbulent flow is created when the direction of laminar air flow is changed too

drastically, and/or flows past an edge or corner of an object.

This includes low momentum diffusion, high momentum convection and rapid

variation of pressure and velocity in space and time.


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3.5.4 Force Balance:-

Besides lift, drag and pitching moment, the airplane is subject to rolling moment,

yawing moment and side force. The wind tunnel force balance is machine that separates

these forces and moments and accurately presents the small differences in large forces.

Drag:-

Drag is a force that is parallel to the motion of an object and directly opposes its

motion. In other words, drag is a force that pushed back against an object in motion.

Drag is affected by:

Shape Surface finish Body protrusions Projected frontal area Speed.

Anytime an object moves through the air, drag is generated. T he more air that is

turned and the more that the air is turned (read that again slowly) the more drag is

generated. This is because the size and shape of the object affects drag.

Figure 4:Four Forces Acting on the Plane


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Drag is the aerodynamic force that opposes an airfoil's motion through the air. It

is a mechanical force that is by the interaction and contact of a solid body with a fluid

(liquid or gas). It is not generated by a force field, in the sense of a gravitational field or

an electromagnetic field, where one object can affect another object without being in

Physical contact. For drag to be generated, the solid body must be in contact with the

fluid. If there is no fluid, there is no drag.

Drag is generated by the difference in velocity between the solid object and the

fluid. There must be motion between the object and the fluid. If there is no motion, there

is no drag. It makes no difference whether the object moves through a static fluid or

whether the fluid moves past a static solid object. Drag acts in a direction that opposes

the motion. (Lift acts perpendicular to the motion).

LIFT

An airplane in flight is the center of a continuous tug of war between four forces:

lift, gravity force or weight, thrust, and drag. Lift and Drag are considered aerodynamic

forces because they exist due to the movement of the airfoil through the air. The weight

pulls down on the body opposing the lift created by air flowing over the airfoil. During

first thrust must overcome drag and lift must overcome the weight before the airfoil can

become airborne. In level flight at constant speed, thrust exactly equals drag and lift

exactly equals the weight or gravity force. For landings thrust must be reduced below the

level of drag and lift below the level of the gravity force or weight.

Lift is produced by a lower pressure created on the upper surface of an airfoil's

wing compared to the pressure on the wing's lower surface, causing the wing to be

"lifted" upward. The special shape of the airplane wing (airfoil) is designed so that air

flowing over it will have to travel a greater distance faster, resulting in a lower pressure

area (see illustration) thus lifting the wing upward.

Lift is a force that acts 90 to the direction of travel of an object. Usually we think

of lift when we think of an airplane. T he plane travels forward (horizontally), and lift

acts 90 to that motion of travel UP!

Lift can only exist where there is laminar flow present.


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Angle of Attack:-

Fig 5: Angle of Attack

The angle of attack is the angle at which the wing is permanently inclined to the

airplanes longitudinal axis. Choosing the right angle of incidence can improve flight of

plane, enhance take-off and landing characteristics and reduce drag in level flight.

The angle of incidence that is usually chosen is the angle of attack at which the

Lift-drag ratio is optimum as shown in fig 9. In most modern airplanes, there is a small

positive angle of incidence so that the wing has a slight angle of attack when the airplane

is in level cruising flight.


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3.5.5 Air through wings

The wing is stationary in the middle of the wind tunnel; air flows past it from right

to left. A little ways upstream of the wing (near the left edge of the figure) I have

arranged a smoke injectors. The smoke is carried past the wing by the airflow, making

visible streamlines.

Figure 6: Air Flow through the Wing

For one thing, we notice that the air just ahead of the wing is moving not just left

to right but also upward; this is called upwash. Similarly, the air just aft of the wing is

moving not just left to right but also downward; this is called downwash. Downwash

behind the wing is relatively easy to understand; the whole purpose of the wing is to

impart some downward motion to the air.

The upwash in front of the wing is a bit more, air is a fluid which means it can

exert pressure on itself as well as other things. The air pressure strongly affects the air,

even the air well in front of the wing.


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CHAPTER NO: 4

DESIGN OF PART


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4.1 Design:

The wind tunnel contains five main parts, the contraction cone at the front of the

tunnel, the test section in the middle of the tunnel, and the diffuser at the back of the

tunnel.

Wind tunnel consisting of following parts

1. Conversion part2. Diffuser3. Test section4. Fan5. Flow conditioning

As our aim to visualization of stream lines over various aerofoils shapes

(vehicle). We used the principle of the venturimeter.

As per standards the venturimeter dimensions are as below:

Test section:

Diameter of test section (d1) or side of test section

d1 = L = 220 mm.

Total length of test section = 220+20+20.

= 260 mm.

20 mm for angle width.

We designed test section is cubic shape, therefore

L = B = H =260 mm.


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Fig 7: Drawing Of Test Section (all dimensions in mm)

Converging part:

We designed wind tunnel is square not circular, therefore the dimensions of

converging parts are

Converging part width = height = 2 *d1

Dimensions are

W1 = H1 = 2* 220 + 20

= 460 mm

tan1 = 1/3

1 is angle

Size for fan spacing =150 mm.

Size for flow conditioning =100 mm.


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Length of converging part (L1) = 3 *100

L1 = 300 mm

Total Length of converging part = 3 *100 + 150 + 100.

Total length of converging part = 550 mm.

Fig 8: Drawing Of Converging Part (all dimension in mm).

Diverging part:

Diverging part width (W2) = height (H2) = 2 * d1

W2 = H2 = 2 * 220 + 20.

= 460 mm.

We have taken 50 mm at the end of diverging part extra, therefore

Length of diverging part (L2) = 500 mm

Total length = 550 mm.


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Fig 9: Drawing of Diverging Part (all dimensions in mm).

Fan:

Dimensions of Fan are

Length of blade = 200 mm.

Diameter of fan cover = 440 mm.

Glass:

Glass thickness = 3 mm

Glass dimension = 240 * 240 mm2.


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As per above standard dimensions with respective fan specification we fabricated

wind tunnel and it is convenient for fabrication and dimensions are as follows

H = L =B = 260 mm

H1 = W1 = 460 mm.

L1 = 300 mm

H2 = W2 = 460 mm

L2 = 500 mm

Size for fan = 150 mm

Flow conditioning length = 100 mm

Fan specification:

Power: 1/2 HP.

Speed: 2800 RPM.

Power supply: 2.7A, 110V AC, 60 Hz

Photograph 1: fan


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4.2 Part List:-

Part Name Material Quantity

Converging part Mild Steel 01

Diverging part Mild Steel 01

Test section Mild Steel/ glass 01/03

Flow conditioning /

honeycomb sectionMild steel 01

Bolt Mild Steel 04

Nut Mild Steel 04

Table No. 4.1 part list


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CHAPTER NO: 5

FABRICATION/ ASSEMBLY


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5.1Fabrication:

Fig 10: Drawing Of Wind Tunnel

We used materials are

CRC sheet of 20 gauges.

L shape angle of 2 cm width of MS material.

We purchased glass for test section from Maharashtra glass

3mm glass used for test section of dimension 24 * 24. We used 3 glasses for top and 2

sides of test section.


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First As per dimension we made the frame with MS angle by using the spot

welding. We made 3 different parts i.e.

1 converging :

As per dimensions we cut the L shape angle and made the frame of conversion

part by using spot welding.

Photograph 2: Frame of Converging Section & Test Section

2 diverging

As per dimensions we cut the L shape angle and made the frame of diversion part

by using spot welding.

Photograph 3: Frame of Converging Part With Fan.


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First of all we made frame of converging part, by using cutter we cut the angle as per

dimension and joined by using spot welding. For cutting purpose we used cutter machine

and welding machine for welding. In converging part fan is situated at start, the fan is

placed at centre and fixed by spot welding.

By the same way we made diverging part and test section.

After forming frame we joined three sections permanently by nut & bolt joint. The total

frame of wind tunnel is now ready.

After that for packing the frame for no flow went outside the sheet metal is

covered on the wind tunnel frame by using seam welding. The CRC sheet metal of 20

gauge is used for covering. The sheet cut as per dimension and requirement. The

converging and diverging part sides are packed and the inlet and outlet of converging and

diverging part kept open for flow purpose. Bottom of test section also packed with sheet

metal.

Remaining part of test section is packed with 3mm glass. One side and top is

fixed and one side kept movable. By using BONDTITE the glass is stick to frame. For

sides special arrangement is made by using welding.

Honey comb section:

As flow of air is turbulent but as per our requirement we need laminar flow so We

made three different arrangement for this

1. CRC plate with holes on it. By using drill machine. This arrangement is placedbetween the assembly of converging and test section.

2. Bunch of plastic pipes or straws are used kept between the end of converging partand test section.

3. CRC plate with hole and on each hole MS pipe same diameter is welded forlaminar flow.

This assembly is joined with Nut- bolt joint


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Photograph 4: Honeycomb


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5.2 ASSEMBLY:

Photograph 5: wind tunnel

The assembly made by fasteners because it is easy to assemble and dissemble.

The frame conversion and test sections are 1st

assembled with fasteners of M12 fastener.

The diversion is joined to test section by M12.

We made stand to mount wind tunnel of height 600mm,

Length= 1400mm, width= 750mm.

As per dimension we made the stand by welding. And then wind tunnel mounted on it.

Two sides of glass are fixed i.e. one side and top. The top glass is joined with

BONDTITE( glue) and bottom is welded by CRC sheet. One side glass is fixed with

welding of angle by sides of the glass, remaining side is movable i.e. can be remove

easily to mount the models.


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Specification:

Length of wind tunnel = 1410 mm.

Height of wind tunnel = 460 mm.

Width of wind tunnel = 460 mm.

Test section size = 260 260 mm2.

Length of stand = 1400 mm.

Height of stand = 600 mm.

Fan speed = 0- 2800 rpm.

Motor = hp.

Fan diameter = 420 mm.


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CHAPTER NO: 6

WORKING/TESTING


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6.1 Working Principle:

The wind tunnel is basically long narrow duct with open circuit with suction

facility where the fan and motor assembly is located at the exit plane of the tunnel

inducing the flow to enter the inlet smoothly and pass through the test section.

A fan creates a steady and straight stream of air that can be controlled. To measure

effect of moving air on the model.

The effect of moving air on the various shapes, understanding of flow through

wind tunnel & air flow pattern can be visualized by this apparatus using smoke

generation method. The ability to calibrate the wind tunnel including pressure and

velocity mapping in the test section.Test instrumentation measures the aerodynamic

forces and moments acting on the model. The three basic forces are lift, drag and side

force as measured in an axis system referenced to the direction of movement of the

model. The drag force is along (but reversed to) the flight path. The lift and side forces

are at are right angles to it.

We use the wind tunnel to the models of proposed airfoil and engine components.

During test the model is placed in the test section of wind tunnel and air is made to flow

past the model.

In wind tunnel test the following should done

1) Calculation of aerodynamic forces on model.2) The model is instrumented to provide diagnostic information about flow of air

around the model. Flow visualization techniques are used to provide diagnostic

information about flow around the model.

3) Decision on angle of attack.


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We can use various visualization techniques that are used in wind tunnel,

1) Smoke generation2) Tufts3) Laser sheet4) Surface oil flow5) Schlieren photography

But tufts and surface oil flow are use to provide information about state of the

boundary layer on the surface to detect flow separation and re-attachment, which is not

our objective. Thats why we use smoke for visualization purpose.

In this experiment assumption is made that the smoke particles are move exactly

with the flow and therefore gives some indication of how the flow moves around the

model. Various types of instrumentation are used during test to determine the forces on

the model and to better understand movement of air around and through the model.

Diagnostic test does not determine forces on the airfoil, but helps the engineer to

better understand how the fluid moves around and through the model. In this case we use

steady state type of flow.


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6.2 Working

We generate the smoke at back side of the fan and starting the fan, fan sucked air

with generated smoke, as flow is passing through the converging part its speed is

increases (we neglect the effect of compressibility). After this the flow passes through the

honeycomb section to reduce turbulence effect and flow becomes linear. As this flow

passing over the test object we observe the stream lines according to shape of object. At

some part of object flow passing over object restricted and eddies forms due to resistance

to the flow of smoked air. The air changes its direction of flow or stream lines passing

over or through the model. Due to moving body eddies forms and flow of air resist the

speed of body or model and get change direction of flow. From this we can change the

shape of model where eddies formed.

By changing the speed of fan using dimmer we can observe the effect of air for

different speeds of air. By using different flow condition we can observe different effects.

We may observe effect of oil and water on the model.

By this we can study or observe the different model and design the different

model shape for different vehicle at different speed

Fig 11: Wind Tunnel Testing Of Passenger Car


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We can measure the lift and drag of several different airfoils using a force balance

In wind tunnel and they compare the results to published data and theoretical

expectations.

Wind tunnel is utilized to study airfoils in free flight. The majority of testing is done on a

scaled down model.

In the automotive industry, wind tunnels are used to study the effects of moving air on

the drag forces and energy consumption of a vehicle moving on the road.

To find the coefficients of lift and drag, CL and CD, respectively.

These coefficients are defined as follows:

CL = 2L/(dV2A) (1)

CD

= 2D/ (dV

2

A)... (2)Where, L is the lift force in N.

D is the drag force in N.

d is the density of the air in kg/m3

v is the velocity of the air in m/s and

A is the horizontal area of the wind (honeycomb section) in m2.

The first step was to find the velocity of the airflow.

The velocity could then be calculated using the equation:

V = 4.3*(h)1/2. (3)

h is difference in height.


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6.3 Testing:

1.Flow conditions:

1. 1.Flow visualization method:Many flows are invisible without any technique. Therefore, various methods have

been created to make the flow visible to human eyes. The prinicipal flow

visualization methods

2. Oil film and oil dots method:The flow on the body surface is visualized by observing a mixture of oil and

pigments or paint spread along the body surface streams due to the flow.

2.Leak test

We test the wind tunnel for leakage. We passed smoke over the wind tunnel and

we observe the leakage of smoke from various part. We controlled the leakage by using

the paper stick or transparent stick.

Testing

Photograph 6 : Testing of Vehicle


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CHAPTER NO: 7

RESULT & DISCUSSION


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7.1 Results: -

We have observed how air flows over the model. We used the smoke to visualize

the air flow through the model. How the drag and lift act on the model. By this we can

design the new model or modify the model. By finding the angle of attack we can

calculate the drag and lift force.


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7.2 Project Expenditure:-

Parts supplier Quantity Amount(Rs.)

CRC sheet Laxmi

fabrication

2 sheets 2500

L Shape MS angle Laxmi

fabrication

25 kg 2500

Fabrication charges Laxmi

fabrication

- 1500

Glass and bonding agent Maharashtra

glass

3 250

Model( wooden) - 2 50Paint Asian paint 150

Straws Mahesh plastic 50 30

Fan Sinni 1 1200

Dimmer and electric charges Wish light 150

MS pipe hollow 5 mm Scrap 1 kg 100

Other 1500

Total 9930

Table No. 5.2 : Project Expenditure

Total cost of project= Rs. 9930/-


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7.3 Applications/Uses: -

To determine aerodynamic loadsWind tunnels are used to determine aerodynamic loads on the immersed structure.

The loads could be static forces and moments or dynamic forces and moments.

Examples are forces and moments on airplane wings, airfoils, and tall buildings.

To study how to improve energy consumption by automobilesThey can also be used on automobiles to measure drag forces with a view to

reducing the power required to move the vehicle on roads and highways.

To study flow patternsTo understand and visualize flow patterns near, and around, engineering

structures. For example, how the wind affects flow around tall structures such as sky

scrapers, factory chimneys, bridges, fences, groups of buildings, etc. How exhaust

gases ejected by factories, laboratories, and hospitals get dispersed in their

environments.

Other uses includeTo teach applied fluid mechanics, demonstrate how mathematical models

compare to experimental results, demonstrate flow patterns, and learn and practice the

use of instruments in measuring flow characteristics such as velocity, pressures, and

torques.


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CHAPTER NO: 8

CONCLUSION & FUTURE SCOPE


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8.1 Conclusion

Wind tunnel is set up is very convenient way for understanding concept of fluid

dynamics and aerodyanamics. It is helpful to carry out qualitative analysis and effect of

air resistance on aerodynamicly designed shape with help of wind tunnel we can visualize

flow pattern and refine the concept of vehicles shape and aerodynamic design .

It is more useful for student to understand the streamlines flow over various

aerofoil shapes and effect of aerofoil shape on minimizing the air resistance and optimize

the operating speed.


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8.2 Future Scope:-

Provision for instrumentation to monitor air speed, angle of attack, chord lengthof new model or different shapes of model.

Scope of design new models. By designing various honeycomb section structure we can observe different flow

patterns.

Recycling of smoke can be done. Blower can be installed to get accurate result. Provision of instrumentation / consol panel to get various results like air speed,

angle of inclination, angle of attack by using angle protract or mechanical /

electronic instrument.

Different Object mounting arrangements can be done


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CHAPTER NO: 9

REFERENCES


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References:-

Books

1. R.K.Bansal, Fluid mechanics, Laxmi publication, new delhi, 5th edition, pageno: 428-459, 651-686.

2. R.K.Rajput, Fluid Mechanics and Hydraulic Machines, S. Chand & companyltd., New delhi , 2005

Web references

1. www.nasa.arc.gov/www/wright/airplane.html2. www.nasa.arc.gov/k-12/airplane/tuncret.html3. www.wikipedia.com/windtunnel.html4. www.wikipedia.org/wiki/Wind_tunnel5. www.users.acsol.net/~nmasters/External_airfoil_flaps.htm,6. www.aerodyn.org/WindTunnel/ttunnels.html7. www.nascar.com/2003/kyn/tech/ccc/02/26/jince_vegas/8. www.windtunnels.arc.nasa.gov/40ft1.html9. www.grc.nasa.gov/WWW/K-2/WindTunnel/history.html10.

www.wrightflyer.org/WindTunnel/testing1.html)


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