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….