manual of basic air flow bench

8/10/2019 Manual of Basic Air Flow Bench

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SOLTEQ BASIC AIR FLOW BENCH (MODEL: FM 21)

1.0 INTRODUCTION

The SOLTEQ Basic Air Flow Bench (Model: FM 21 has been designed todemonstrate the principles of the flowing compressible fluid. Ability to study the boundarylayer growth, the behavior of jet dispersion, aerodynamics studies and flow visualization..

The unit comes with a motor driven centrifugal fan and various of interchangeable optionaltest sets such as multi-tubes manometer test set, venturi, orifice and pitot tube test set,Bernoullis theorem test set, flow around a bend test set, pressure losses in pipes test set,aerodynamics studies accessories, smoe generator for flow visualization, jet dispersiontest set and boundary layer growth test set. The air flow rate through the duct is adjustable.

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2.0 !"N"RA# D"$CRI%TION

The SOLTEQBasic Air Flow Bench (Model: FM 21 is a mobile unitconsisting of anepo!y coated steel frame, motor driven centrifugal fan and necessary accessories. "arioustest sets can be supplied with the unit for students to e!periment on the principles of

compressible fluid flow.

The accessories supplied with the bench comprise the optional #et $ispersion Test %et, theBoundary &ayer 'rowth Test %et, Aerodynamics studies set and smoe generator for flowvisualization stidies. A differential pressure transmitter is supplied for the differentialpressure measurements.

The inlet and outlet ducting of the centrifugal fan is designed with flow straightness, outputpressure tapping and a flow regulating valve (damper) at the air outlet. The ductingsections and the test sections can be easily assembled together using the latch clamps.*ubber + ring used to seal the connecting ducting sections.

!perimental setup for the jet dispersion re/uires the plenum chamber and the pitot tubeassembly that comes with vertical and horizontal scales . Thus the traverse pitot tube headcan be determined in relationship to the air jet stream. The plenum is connected to the sideoutlet port at the centrifugal fan outlet duct. 0hen the jet dispersion test set is not inoperation, close the side outlet port with the 1"2 cap provided. The pitot tube is used withthe differential pressure transmitter supplied.

!periment for boundary layer growth re/uires a transparent wind tunnel with slots for theinstallation of the boundary layer test plates and the pitot tubes. The studies involve thedetermination of the thicness of the boundary layer and the velocity profile within it. Theseparameters will vary with velocity of the fluid flowing over the surface, the distance from theleading edge of the surface and the degree of roughness of the surface. Two test platesare supplied, one with blunt leading edge and the other one with sharp leading edge. Twopitot tubes are supplied for the measurements of the total pressure and the dynamicpressure in the boundary layer.

!periments for aerodynamics studies re/uire an aerofoil unit, a cylinder unit and the twocomponents balance. The studies involve the determination of lift and drag coefficient as

well as the pressure profile around the test body.

!periments for flow visualization re/uire a smoe generator and the test specimens(aerofoil and cylindrical body). The smoe generator generates stream lines to visualize theflow pattern around a test specimen.

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2.1 Uni& Asse'l)

Figure 1:Assembly for Basic Air 3low Bench

4. 3low *egulating "alve ($amper) 5. 1lenum 2hamber (ptional)

6. utlet $uct 7. Bell 8outh

3

9

:

;

4

10

nlet $uct :. 1itot Tube

9. %ide utlet 1ort

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2.2 "*+eri'en&al Ca+aili&ies

- $emonstration of the variation of velocity of an air stream emitting from acircular pipe into free surroundings, at different distances along its central a!is(with optional #et $ispersion ?nit)

- %tudy the velocity profile of an air stream emitting from a circular pipe into freesurroundings, at various distances from the emission point (with optional #et$ispersion ?nit)

- $etermine the velocity profile of a boundary layer at specified distance from@blunt leading edge of a @ smooth test plate (turbulent flow condition) (withoptional Boundary &ayer ?nit)

- $etermine the velocity profile of a boundary layer at specified distance from@sharp leading edge of a @smooth test plate (laminar flow condition) (withoptional Boundary &ayer ?nit)

- To study the pressure profile around a transverse cylinder and derivation ofdrag force coefficient (with optional 0ind Tunnel $emonstration and &ift and

$rag 3orces ?nit)- To study the pressure profile around an aerofoil section and derivation of lift

and drag forces and coefficients (with optional 0ind Tunnel $emonstrationand &ift and $rag 3orces ?nit)

- "ariation of lift and drag forces and coefficients and lift and drag ratio withaerofoil incidence (with optional 0ind Tunnel $emonstration and &ift and $rag3orces ?nit)

2., $+eci-ica&ions

A bench unit designed to allow e!periments on boundary layer and jet dispersion.

a) Bench8ade of epo!y coated steel frame constructed with castors.

b) Fan1ower supply 6; C =" ;D3re/uency 9Ezutput .990*ated 2urrent 4.= F 4.9 A

8otor speed 6nlet : mm long G 6 H diameterutlet 64 mm long G 6 H diameter2alibrated %cales

Eeight positioning arm F 9 mm*adial movement arm F 6 mm

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d) Boundary Layer Growth Test Set (Optional)

Boundary &ayer 'rowth $uct8aterial Transparent Acrylic with aluminium bell mouth2ross %ection 59 mm ! 69 mm

Test 1osition from the test plate leading 9mm, :mm, 49mm, 69mm1itot Tubesi) Total 1ressure Tube with calibrated traverse scale (-49mmI .4mm)ii) 1itot %tatic TubeTest 1latesi) %mooth surface sharp leading edgeii) %mooth surface blunt leading edge

e) Differential Pressure Transitter (optional)1ressure *anges - 4 1a

Accuracy J 4K of full scale

f) !erofoil Section (optional)8aterial Acrilic2ord &ength, c 59 mmThicness, t < mm%pan, b 59 mm

") #ylinder Section (optional)8aterial Acrilic$iameter, d 4; mm&ength, & 59 mm

h) Two #oponents Balance (optional)>ndependent measurement of lift and drag by uni/ue vertical and horizontalbalance beamsBalance *ange 9 g

i) So$e Generator (optional)%moe utput F 4= m;Cmin

%moe 1article %ize .6 F .; micron1ower 6.6 0

2. O/erall Di'ensions

Eeight 6.69 m$epth .79 m0idth 4.79 m

2. !eneral Reire'en&s

lectrical =49"A2C;-phaseC9 Ez

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,.0 $UMMAR3 OF T4"OR3

,.1 5e& Dis+ersion Measre'en&

*eferring to 3igure 6, a jet of air emerging into free surroundings from an outlet

nozzle locate in a plenum chamber. Air will emerge from the chamber with avelocity voand for some distance from the end of the nozzle, a conical core of airhaving this velocity e!ists. The initial mass of emitted air m o is added to by acontinuous ingress of air form the surroundings, and hence the total mass of airinvolved increases progressively as the distance from the nozzle end increases.But, as the distance from the nozzle end increases, the velocity of the air jetprogressively decreases.

Figure 2:#et %tream

8omentum can be defined as Lmass in motion.L All objects have mass, so if anobject is moving, then it has momentum. The amount of momentum is dependentupon two variables how much and how fast it is moving. The 8omentum Theorystate that the momentum of the fluid stream will remain constant along its pathfrom the nozzle, and will be e/ual to the air emergent momentum,

vo mo

Thus at a plane @a, some distance from the nozzle

8omentum M Aa

vadm M vo mo

where Aais the area of the jet stream at a plane @a

8omentum M R

0

va 6!d! va

M 6 R

0

va6! d!

M constant

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>f velocity profiles are drawn for the jet stream at various distances from theemission point, the total mass of the stream in any plane can be obtained bysummation

.

m M 6

1

1

n

++

2

)1()( iviv

++

2

)1()( ixix

[ ])()1( ixix

+

%imilarly the momentum can be obtained

8omentum M 61

1

n2

2

)1()(

++ iviv

++

2

)1()( ixix[ ])()1( ixix +

,.2 Bondar) #a)er !row&h

0hen a fluid flows over a stationary surface, e.g. the bed of a river or the wall of asolid, the fluid touching the surface is brought to rest by the shear stress t oat the

wall. The velocity increases from the wall to a ma!imum in the main stream of theflow.

&ooing at the 3igure ;, we get the above velocity profile from the wall to thecenter of the flow. This profile does not just e!it, it must build up gradually from thepoint where the fluid starts to flow past the surface - e.g. when it enters a pipe. >f

we consider a flat plate in the middle of a fluid, we will loo at the build up of thevelocity profile as the fluid moves over the plate.

Figure 3:"elocity 1rofile

The region, where there is a velocity profile in the flow due to the shear stress atthe wall, we call it the boundary layer. The stages of the formation of the boundarylayer are shown in the 3igure =. The flow in the section of the boundary layerimmediately after the leading edge is always laminar irrespective of whether themain flow is laminar or turbulent. The laminar layer is characterized by a fairlyuniform increases in velocity with increasing distance from plate. But, turbulent

flow shows much more rapid increase in velocity near the surface. 0e define thethicness of this boundary layer as the distance from the wall to the point where


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the velocity is ::K of the Lfree streamL velocity. Boundary layer thicness ( ), d M

distance from wall to point where u M .:: u .

Figure 4:3ormation of Boundary &ayer

3or a laminar flow, its value of * e(!) is below 6and for values above = , the

flow is turbulent. The *e(!) for transition region is higher than laminar but lowercompare to turbulent, *e(!) &aminar N *e(!) Transition N *e(!) Turbulent.

3ormulae to calculate the *eynolds number is given below

*eynolds number, *e(!) M u ! C

where

u M velocity of free air stream (mCs)! M distance from leading edge (m) M density of air (gCm;) M viscosity of air (OsCm6)

A further definition of the boundary layer thicness is given by the definition ofdisplacement thicness, . 2onsidering a flow pattern as shown in 3igure 9, urepresents the velocity of air stream parallel to the surface and at a perpendiculaydistance @y from it. the volume flow rate per unit width through an element ofthicness, y in two dimensional flow is u y. >f however there had been no

boundary layer the value would have been u .

Eence,

reduction in flow M dyuu )(

0

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The @displacement thicness P is defined as that distance which the surfacewould have to be displaced to modify the flow to the same e!tent.

i.e. PM 4Cu dyuu )(

0

M dyu

u)(

10

Figure 5:$isplacement Thicness

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,., #i-& and Dra6 Force

The resistance of a body as it moves through a fluid is of obvious technicalimportance in hydrodynamics and aerodynamics. >n this e!periment we place acircular cylinder in an air stream and measure its resistance, or drag, by three

methods. 0e start by introducing the ideas which underline these methods.

2onsider the cylindrical body shown in cross-section in 3igure 5.

Figure 6:%chematic *epresentation of 3low *ound a 2ylinder

The reader may be unfamiliar with the idea of a non-circular cylinder. >n thepresent conte!t the word LcylinderL is used to describe a body which is generatedby a straight line moving round a plane closed curve, its direction being alwaysnormal to the plane of the curve. 3or e!ample, a pencil of he!agonal cross-sectionis by this definition a cylinder. The curve shown in 3igure 6 represents a section ofan oval cylinder. An essential property of a cylinder is that its geometry is two-dimensionalI each cross-section is e!actly the same as every other cross-section,so that its shape may be described without reference to the dimension along thecylinder a!is. 0e shall use the term circular cylinder to denote the particular andimportant case of the cylinder of circular cross-section. 8otion of the cylinderthrough stationary fluid produces stresses on its surface which give rise to aresultant force. >t is usually convenient to analyze these stresses from the point ofview of an observer moving with the cylinder, to whom the fluid appears to beapproaching as a uniform stream. At any chosen point A of the surface of the

cylinder, the effect of the fluid may conveniently resolved into two components,pressure p normal to the surface and shear stress tangential to the surface. >t is

convenient to refer absolute pressure p to a reference static pressure p atm in theoncoming streamI 1 is then a gauge pressure.

atmppP =

&et ?denote the undisturbed uniform speed of the motion upstream of the

cylinder and the density of the fluid. QOote, we will use other ? or ? to denote

the free stream speed.

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The dynamic pressure in the undisturbed stream2

2

1U is then given by

= pPU 2

2

1

where 1is the total pressure in the oncoming stream. The dynamic pressure is auseful /uantity by which the gauge pressure p and shear stress may be non-

dimensionalised, yielding the following dimensionless terms

2

2

1

=U

pcp

2

2

1

=U

cf

where cp is the (local) pressure coefficient and cf is the (local) sin frictioncoefficient.

The combined effect of pressure and shear stress (sometimes called sin friction)gives rise to a resultant force on the cylinder. This resultant may conveniently beresolved into the following force and tor/ue components (acting at any chosenorigin 2 of the section as shown on 3igure 5)

A component in the direction of ?, called the drag force, $.

A component normal to the direction of ? called the lift force, &.

A moment about the origin 2, called the pitching moment, 8.

These components may be e!pressed in dimensionless terms by definition of drag,lift, and pitching moment coefficients as follows

dlU

DCD

2

2

1

=

dlU

LCL

2

2

1

=

dlU

MCM

2

2

1

=

where 2$is the drag coefficient, 2& is the lift coefficient, and 28 is the pitching

moment coefficient. Oote that d is a length that characterizes the cross-sectionalsize of the cylinder while l is the length of the cylinder. >n 3igure 5, d is shown as

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the width measured across the cylinder, normal to ?, which is the usual

convention. (An important e!ception is the aerofoil, where the length in thedirection of flow or LchordL of the section is used instead). The coefficients 2$, 2&,and 28 are of prime importance, since they are invariably used for correlatingaerodynamic force measurements.

,. Flow 7isali8a&ion

3low visualization in air may be broadly divided into surface flow visualization andoff-the-surface visualization. %urface flow visualization involves tufts, fluorescentdye, oil or special clay mi!tures which are applied to the surface of a model. "isualinspection of such tufts and coatings as a function of time, or after some time, willgive valuable information on such things as the state of the boundary layer(laminar or turbulent), transition, regions of separated flow and the lie. >t must beremembered in such visualization that what is observed on the surface is notalways indicative of what is happening away from the surface.

The second type of visualization is off the surface and involves the use of suchtracers as smoe particles, oil droplets or helium-filled soap bubbles. Thevisualization medium must faithfully follow the flow pattern or it is not conveying thecorrect information. The smoe particles and oil droplets are very small and arelight enough that they will follow the motion of the flowI the soap bubbles are smalland are filled with helium to mae them neutrally buoyant. ach of these methodsre/uires appropriate lighting and some device for recording the image such as astill or video camera. >f the flowfield is illuminated in a plane by appropriatemasing of the light source it is possible to e!amine discrete sections or slices of

the flow. 3or e!ample, a laser light beam can be e!panded into a thin sheet bypassing it through a cylindrical lens. This sheet then can be used to illuminate anycross-section of an airflow that has been seeded with particles. The laser light willreflect from the particles, but dar images will be observed where there is anabsence of particles, such as in the center of a vorte!. A vorte! core is almost voidof particles since they have been spun out by the action of centrifugal force.

>n addition to flow visualization using tracer particles or surface coatings, opticalmeans can be used to visualize flows or flow features. 3or e!ample, laser lightsystems are used to produce holographs that can be used for densitymeasurement and flow visualization even at low subsonic 8ach numbers. 3or

compressible flows, %chlieren systems, which respond to density gradients, areused to optically determine the locations of shoc waves and e!pansion regionsbut they will not accurately provide the values of flow properties. An optical methodthat will accurately yield the magnitude of the density anywhere in the flow isbased upon the principle of interference. A light ray is split into two optical paths,one passing through the test section and the other through a reference air column.The two beams then are merged and refocused on a screen. The screen showsareas of light and dar (fringes) because there is a phase difference between thetwo beams which depends upon the difference in the lengths of their light paths.By taing pictures with and without flow in the test section, fringe shifts will beobserved from which an e/uivalent change in optical path may be determined.

This change, in turn, can be related to a change in density so that contours of

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nown density in the test section can be found. This optical measuring device iscalled an interferometer.

3low visualization is also carried out in water flows because the visualization iseasier, although it must be recognized that the *eynolds number of such a flow

may be /uite different from that of the air flow under study. The water may beinjected with dyes of different colors either through small orifices in the modelsurface or upstream so as to act as streamline tracers. *egions of the flowfieldalso may be visualized by generating small hydrogen bubbles in the water which

will move with the water flow. >n this techni/ue, a fine wire cathode is positioned inthe water and connected to a $2 power supplyI the anode is located elsewhere inthe water. The circuit thus is completed through the water (the water conductivitycan be enhanced by the addition of a salt, for e!ample, if necessary). 0hen thecircuit switch is closed, small hydrogen bubbles are emitted from the wire cathode

which then is swept along with the water flow. These bubbles may be viewed withproper lighting.

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.0 "9%"RIM"NTA# %ROC"DUR"$

.1 "*+eri'en&al %rocedres -or 5e& Dis+ersion $&d) (O+&ional

.1.1 "*+eri'en& 1: De&er'ina&ion o- /eloci&) +ro-ile alon6 cen&ral a*is

O#$e%&i'e:To determine the variation in velocity of an air stream emitting from acircular pipe, into free surroundings, at different distance along its centrala!is

r%e*ure+:4. 1osition the pitot tube so that its nose is mm above the outlet pipe

and on the pipeRs center line. No&e:The nose of the pitot tube should point vertically downwards into the air stream

6. Adjust the fan outlet flow regulating valve so that the dynamicCvelocitypressure reading taen from the pilot tube is appro!imately ; 1a.

;. Then, record the e!act reading obtained.=. Seeping the fan outlet flow regulating valve in the same position, record

the pressure readings along the pipes e!tended center line atincrements of 6 mm from F 9 mm.

,-+.:1lot the reciprocal values of velocity against distance from the datum (i.e.air e!it point) and comment.

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.,.2 "*+eri'en& 2: $&d) &he /eloci&) +ro-ile o- an air s&rea' e'i&&in6-ro' a circlar +i+e in&o -ree srrondin6s a& /arios dis&ances -ro'&he e'ission +oin&

O#$e%&i'e:

To determine the velocity profile of an air stream, emitting from a circularpipe into free surroundings, at various distances from the emission point.

r%e*ure+:4. 1osition the pitot tube so that its nose is 4 mm above the outlet pipe

and on the pipeRs center line.No&e:The nose of the pitot tube should point vertically downwards intothe air stream.

6. Adjust the fan outlet flow regulating valve so that the dynamicCvelocitypressure reading taen from the pilot tube is appro!imately ; 1a.

;. btain a velocity profile at this 4 mm plane by taing a series of

readings of dynamicCvelocity pressure at radial increments of 4 mm,from the central position ( mm) to a ma!imum distance from thiscentral position where it is still possible to obtain a valid reading.

=. *epeat this procedure to obtain the velocity profiles at planes of 6,; and = mm from the outlet pipe.

,-+.:1lot the values of velocity against radius for each value of distance awayfrom the emission point.

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.2 "*+eri'en&al %rocedres -or Bondar) #a)er !row&h $&d) (O+&ional

.2.1 "*+eri'en& 1 : De&er'ina&ion o- /eloci&) +ro-ile o- &he ondar) la)era& s+eci-ied dis&ances -ro' &he ln& leadin6 ed6e o- a s'oo&h &es&+la&e in &rlen& -low condi&ions

O#$e%&i'e+:To determine the velocity profile of the boundary layer at specifieddistances from the blunt leading edge of a smooth test plate in turbulentflow conditions

r%e*ure+:4. >nstall the blunt leading edge test plate into the slot provided.6. 1osition the total pressure tube (1itot 6) in slot = of the tunnel.;. 1osition the pitot static tube assembly (1itot 4) in slot 4 and direct the

nose of the pitot static tube upstream, and locate the measurement

position appro!imately midway between the plane of the top surface ofthe test plate and the under surface of the top of the tunnel.No&e %lots not occupied by the static pressure tapping plate must beclosed with the transparent plates provided.

=. %tart the fan and then adjust the fan outlet flow regulating valve until apressure of appro!imately 65 1a is obtained as measured by thepitot static tube (1itot 4).

9. *ecord the value of static pressure for slot number 4. *epeat the staticpressure measurement for the other three slots.

5. Then, position the total pressure tube which measures the totalpressure (1itot 6) into slot 4.

7. Adjust the pitot tube until the nose just touches the surface of the testplate and note the reading on the micrometer scale.

t is important to re-establish the datum for verniermeasurement each time the slot position is changed.

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.2.2 "*+eri'en& 2 : De&er'ina&ion o- /eloci&) +ro-ile o- &he ondar) la)era& s+eci-ied dis&ances -ro' &he shar+ leadin6 ed6e o- a s'oo&h &es&+la&e in la'inar -low condi&ions

O#$e%&i'e+:

To determine the velocity profile of the boundary layer at specifieddistances from the sharp leading edge of a smooth test plate in laminarflow conditions

r%e*ure+:4. >nstall the sharp leading edge test plate into the slot provided.6. 1osition the total pressure tube (1itot 6) in slot = of the tunnel.;. 1osition the pitot static tube assembly (1itot 4) in slot 4 and direct the

nose of the pitot static tube upstream, and locate the measurementposition appro!imately midway between the plane of the top surface ofthe test plate and the under surface of the top of the tunnel.

No&e %lots not occupied by the static pressure tapping plate must beclosed with the transparent plates provided.

=. %tart the fan and then adjust the fan outlet flow regulating valve until apressure of appro!imately 9 1a is obtained as measured by the pitotstatic tube (1itot 4).

9. *ecord the value of static pressure for slot number 4. *epeat the staticpressure measurement for the other three slots.

5. Then, position the total pressure tube which measures the totalpressure (1itot 6) into slot 4.

7. Adjust the pitot tube until the nose just touches the surface of the testplate and note the reading on the micrometer scale.

and 6)

.9 F ;. mm in .4 mm increments (1osition ;).9 F =. mm in .4 mm increments (1osition =)

4. *epeat steps 9-< for the other three slots.No&e: >t is important to re-establish the datum for verniermeasurement each time the slot position is changed.

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,-+.:4. 2alculate the dynamicCvelocity pressure for each position of the pitot

tube by subtracting the relevant value of static pressure from the valueof total pressure.

6. The ratiou

uis given by

u

uM

( )

21

ma!statictotal

statictotal

pp

pp

where ( )ma!statictotal

pp is the velocity pressure of the free air

stream at ma!imum distance from the plate.

2onstruct the boundary layer velocity profiles.

;. 2hec the type of flow occurring at the boundary layerCplaneintersections by checing the *eynolds Oumber.

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., Aerod)na'ic $&dies o- an Aero-oil Bod) (O+&ional

O#$e%&i'e+:4. To obtain drag force and drag coefficient for cylinder body.6. To obtain pressure distribution as a function of the angle to the direction of

flow.

r%e*ure+:4. >nsert the aerofoil body into the duct.6. %et up the two components balance properly with the counter force strings

attached to the electronic balance. 8ae sure that the assembly is balancedusing the counter weights and record the initial balance readings.

;. 1osition the 1itot tube to center of the duct.=. 2onnect the aerofoil to the water manometer using a tubes at 1oint 4 until

1oint 4= (1lease refer to Appendi! A for >llustration $iagram).9. Turn on the radial fan and obtain a static pressure reading of -49 1a.

5. Oow the wind will create a lift as well as a drag force.7. 1osition the aerofoil at an attac angle of -9 deg, record the reading on the lift

and drag forces balance and calculate the lift and drag force by applying thefollowing factor

$rag 3orce, $ (O) M1000

)(Re gadingBalance! .9 ! :.


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. Aerod)na'ic $&dies o- a C)lindrical Bod) (O+&ional

O#$e%&i'e+:4. To obtain drag force and drag coefficient for cylinder body.6. To obtain pressure distribution as a function of the angle to the direction of

flow.

r%e*ure+:4. >nsert the cylinder body into the duct.6. %et up the two components balance properly with the counter force strings

attached to the electronic balance. 8ae sure that the assembly is balancedusing the counter weights and record the initial balance reading.

;. 1osition the 1itot tube to center of the duct. Turn on the radial fan and obtain astatic pressure reading of -6 1a.

=. Oow the wind will push the front part of the cylinder bac and create a dragforce.

9. *ecord the reading on the drag force balance and calculate the drag force byapplying the following factor

$rag 3orce, $ (O) M1000

)(Re gadingBalance! .9 ! :.


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. Flow 7isali8a&ion $&dies

O#$e%&i'e+:To study the flow lines around different bodies.

r%e*ure+:

4. 3or smoe generator, move power switch to O (4) position. The @*ed>ndicator &ight will illuminate immediately. After appro!imately 9 F 4 minutesthe @'reen Temperature &ight will illuminate, indicating that the correct woringtemperature has been reached (For o+&i'' +er-or'ance i& isreco''ended &ha& &he 'achine e allowed &o war' + -or an addi&ional10 'in&es e-ore s'o;e is +rodced.

NOT": $o not attempt to generate smoe until the @'reen Temperature &ight

has come on, otherwise damage may be caused to the machine.

6. >nsert rotating wing into the viewing window. 1osition it pointing downwards.;. Turn on radial fan. 2ontrol the air flow velocity by adjusting the damper.=. 1ress @%moe Button on smoe generator.

N&e: >t is advisable to be operated9. bserve the flow lines through the viewing window and setch the stream

lines.5. 3or rotating wing only, fi! = different attac angles, observe and capture the

stream lines.7. !periment is repeated by using cylinder body and orifice.

,-+.:%tudy and analyze the flow lines produced.

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.0 MAINT"NANC" AND $AF"T3 %R"CAUTION

4. Always run the e!periment after fully understands the unit and procedures.6. Always wear protective clothing, shoes, helmet and goggles throughout the laboratory

session.

;. Be e!tremely careful when handling the pitot static tube as the sharp end may causeeyes injury.

=. The apparatus should not be e!posed to any shoc and stresses. The apparatusshould be stored properly to prevent damage.

9. 2lean and wipe the bench with damp cloth after every laboratory session.

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manual of basic air flow bench

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