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BLOWER BALANCE FOR SMALL ASPECT RATIO

DESCRIPTION:

The equipment has been designed as an experimental unit to study

the Co-efficient of Lift and Co-efficient of Drag for different aspect ratios of the

model. The test rig essentially consists of axial blower handling the air as the

medium of flow and is driven by AC otor. The test rig has provisions for

varying the parameters! vi".! and speed! in turn flow and head. The specially

designed AC electric drive facilities the accurate calculations of input horse

power to blower.

Aspect ratio # b$%s & b # breadth of the model!

s # span of the model

SPECIFICATIONS:

'. (L)*+, T+ / a0 Axial with circular duct for 1Delivery 2 3uction0

b0 )perated at 456".

$. )T), / AC otor with thyristor speed controller 1AC Drive0

7. D,89+ / AC. type

:. +L+CT,8CAL / 3ingle ph.! $$5 9! AC supply with ;eutral and

8;

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;ote/ During the adBustment of angle the direction of Angle is ositive towards

down and ;egative towards top.

DIAGRAM:

(-)

b

3 (+)

GRAPHS:

'. Angle of attac@ v%s co-efficient of lift

$. Angle of attac@ v%s co-efficient of Drag

TABLE OF READINGS AND CALCULATION(GUIDANCE ONLY):

Aspect

ratio

odel Angle of

attac@10

Lift

in

=g

Drag

in

=g

Coefficient

of Lift

CL

Coefficient

of Drag

CD

velocity

FORMULAE USED: *here!

L L # Lift force in =g

Coefficient of Lift CL# ----------------- D # Drag force in =g

'%$9$A 9 # 9elocity of air m%sec

A # Area of the model

D # Density of air

Coefficient of Drag CD# ----------------

'%$9$

A

$

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TABLE OF READINGS AND CALCULATION:

Veloc!" # $%& ' A*ec! ,!o # %&&. S#%/.

3+T,8CAL A+,))8L ) 3#5.'45

Aspect

ratio

odel Angleof

Attac@

C)3

9elocity Liftorce

1A0

=g

Dragorce

=g

A# sEcs#5.'4m

c#5.'m

T in =g CL CD

%001

SYMMETRIC

AL

AEROFOIL

/ $%& %& %2 %/. %0./ %3/ %0/

5.5F -4 5.GG H.$ -5.5' 5.54 5.5'45 5.:H -5.5'4 5.5FF

5.5F -'5 5.GH: H.$ -5.57 5.54 5.5'45 5.:5 -5.5:F 5.5FH

5.5F -'4 5.G4 H.$ -5.5F 5.5H 5.5'45 5.$H -5.''$ 5.'$F

5.5F 4 5.GG H.$ 5.54 5.5: 5.5'45 5.:H 5.5FF 5.5$5.5F '5 5.GH: H.$ 5.' 5.54 5.5'45 5.:5 5.'4 5.5FH

5.5F '4 5.G4 H.$ 5.'F 5.5G 5.5'45 5.$H 5.$F' 5.':7

Veloc!" # $%& ' A*ec! ,!o # %/ S#%/

3+T,8CAL A+,))8L ) 3#5.'55

Aspect

ratio

odel Angleof

Attac@

C)3

9elocity Liftorce

1A0

=g

Dragorce

=g

A# 3ECb#5.'55m

c#5.'55m

T in=g

CL in =gf CD in=gf

5.'555

3+T

,8CAL

A+,))8

L

5 ' H.$ 5.57 5.5' 5.5'55 5.:57 5.5F: 5.5$4

5.'555 -4 5.GG H.$ -5.5' 5.57 5.5'55 5.:5$ -5.5$4 5.5F4

5.'555 -'5 5.GH: H.$ -5.5$ 5.5: 5.5'55 5.7GF -5.545 5.'5'

5.'555 -'4 5.G4 H.$ -5.5: 5.54 5.5'55 5.7HG -5.'57 5.'$H

5.'555 -$5 5.G7G H.$ -5.54 5.5 5.5'55 5.7FG -5.'7$ 5.'4H

5.'555 4 5.GG H.$ 5.5$ 5.57 5.5'55 5.:5$ 5.545 5.5F4

5.'555 '5 5.GH: H.$ 5.5 5.5: 5.5'55 5.7GF 5.'4' 5.'5'5.'555 '4 5.G4 H.$ 5.5G 5.5: 5.5'55 5.7HG 5.$7' 5.'57

5.'555 $5 5.G7G H.$ 5.'' 5.54 5.5'55 5.7FG 5.$G5 5.'7$

GRAPHS:

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SAMPLE CALCULATION/

A 9$

Theoretical force t# -------------

$

L

Coefficient of Lift CL# -----------------

t

L L # Actual Lift force in =g

Coefficient of Lift CL# ----------------- D #Actual Drag force in =g

'%$9$

A

5.5$

# ----------------------------------------------- # %3/ 45

5.4 I '.$G I 1H.$0$I 5.'45 x 5.'55

*here!

9 # 9elocity of air m%sec

A #Area of the model#b x C

b # length of aerofoil ! C # Chord of the aerofoil

# Density of air # '.$G =g%m

7

D

Coefficient of Drag CD # ------------

'%$9$3

%2

# ----------------------------------------------- # %0/ 45

%.I'.$G I 1H.$0$ I 5.'45I5.'55

Aspect ratio # b$%s & b # breadth of the model! # 15.'0 $% 5.'4 s # span of the model

# %001

4