impact of jet on a fixed curved plate
TRANSCRIPT
Gandhinagar Institute of Technology
Subject :- Fluid Power Engineering
MECHANICAL ENGINEERING 5th - B : 2
Impact of jet on curved plate
Prepared By – Pavan Narkhede [130120119111]
Guided By : Prof. Parth Panchal
Impact of liquid jet on a fixed curved plate
1) When the jet strikes at the centre of the symmetrical blade
The plate is smooth and there is no loss of energy due to impact of jet.
Force exerted by jet in the direction of jet,
Force exerted by jet on curved fixed plate in vertical direction,
]cos1[
)]cos([)(][V) water/secof mass(
2
21x
AVF
VVAVFVF
x
x
xx
sin
]sin0[)(
][)(
2
21
AVF
VAVF
VVAVF
y
y
yyy
2) When jet strikes tangentially at one end of symmetrical plate
2180diflection of Angle
0
]sinsin[)(
)( AV)( 21
y
y
yyy
F
VVAVF
VVF
cos2
)]cos(cos[)()( AV)(
2
21
AVF
VVAVFVVF
x
x
xxx
Consider a water jet striking on symmetrical curved plate tangentially at one end as shown in figure.
3) When jet strikes tangentially at one end of unsymmetrical plate
)(180 diflection of Angle
]sin[sin
]cos[cos2
2
AVF
AVF
y
x
Impact of liquid jet on a moving curved plate1) When jet strikes at the centre and plate moving in the direction of
jet.
The relative velocity between jet and plate = V – u. Force exerted by water jet on moving curved plate
Work done by the jet on the plate/second
]cos1[)(
)]cos1)()[(()]cos)(()[(Vplate) thestrikesjet ith which velocity w(
2
uVAF
uVuVAFuVuA
x
x
]cos1[)Au(V.
second moved distance 2
uDW
Fx
Impact of jet on a moving curved plate2) When jet strikes tangentially at one of the tips
1) Force exerted by the jet in the direction of motion
2) Work done per unit weight of fluid striking per second
][ , of any value Therefore,
][ ,90 If][ ,0 ,90 If
][ ,90, If
211
2
2112
1122
211221
wwrx
wwrx
wrxw
wwrx
VVAVF
VVAVFVAVFVthen
VVAVFuu
Nm/Kg ,][ 21 uVVWD ww
3) Power developed, P=work done in J/s
4) Blade efficiency or jet efficiency
5) Angle of Deflection
uVVAVP wwr ][ 211
31
211 ][2V
uVVV wwrb
)(180 21
The effect of angle of plat on forceWater leaves the nozzle at a velocity with force until it hits the plate, for a flat
plate the force generated is minimum return but maximum force moving that plate where it has minimal deflection. As the plate curvature increases the resultant deflection is smoother and less ‘beating’ of the plate, hence the force returning increases. The angle increase will improve force.
Newton’s 3rd law explains for every action there is a equal and opposite reaction and this is proved by the results table where the increase in force arrow increase’s with the plate’s angle. Please refer to diagram below to aid my best attempt of an explanation:
It is clear the hemisphere is more suitable, followed by the curved plated followed by the flat plate. By the statements above the oblique plate would have been more efficient than the flat plate and less efficient than the curved with it’s deflection angle at 60 degrees.
Experiment of impact of jet on curve plate
THANK YOU….