1. IMPACT OF JETS ON THE MOVING
PLATE
Prepared by:
Binod poudel
069/BME/409
1
2. FORCE EXERTED ON MOVING FLAT
PLATE HELD NORMAL TO JET
Let a fluid of density ρ moving with velocity V be striking a plate moving in the
same direction with the velocity of u.
So, relative velocity of jet = V-u
And mass of fluid striking jet per second = ρa(V-u)
Force exerted by jet = mass of fluid striking per sec * change in velocity
= ρa(V-u)*(V-u – 0)
=ρa(V-u)2
2
3. FORCE EXERTED ON A MOVING PLATE HELD
INCLINED TO THE DIRECTION OF JET
The angle between the jet and plate is θ as shown in the figure.
Relative velocity with which jet strikes the plate is (V-u)
Mass of fluid striking plate per second is ρa(V-u)
Force exerted in the direction normal to the plate is ρa(V-u)[(V-u)sinθ-0]
Fn = ρa(V-u) 2sinθ
Component of this force in the direction of jet = Fn sinθ
= ρa(V-u) 2sin2θ
3
4. FORCE EXERTED ON A CURVED PLATE
MOVING IN THE DIRECTION OF JET
Let, V be the absolute velocity of the jet, a be the area of jet and u be the velocity
of the vane in the direction of jet.
So, relative velocity of the jet is (V-u) and after striking the component of this
velocity in the direction of jet is -(V-u)cosθ (opposite in direction) as shown in
figure.
Mass of fluid striking the plate per second = ρa(V-u)
Force exerted by the jet in the direction of jet = ρa(V-u)[(V-u)-{-(V-u) cosθ}]
= ρa(V-u)2(1+ cosθ)
4
