blower balance
TRANSCRIPT
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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
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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
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