Impulse of Jets Notes | Study Mechanical Engineering SSC JE (Technical) - Mechanical Engineering

IMPULSE OF JETS

• Jet Strikes normal to the flat stationary plate

Force exerted by the jet normal to the plate
P_n = ρaV²
a = area of jet
V = velocity of jet 

• Jet strikes on a inclined stationary plate

• Force exerted by the jet normal to the plate

•  Force exerted by jet on moving flat plate normal to jet.

u = plate velocity
P_n  = ρa(V – u)²
Work done per second (W) = P_n × u = ra[V – u]² × u 

• Jet strikes on series of flat plat mounted on the periphery of wheel

P_n = ρaV(V – u)
Work done by the jet = P_n × U
W = ρaV(V – u)u

Efficiency of the work done of wheel h =
at ,

•  Jet striking on a symmetrical stationary curved plate

P_n = ρaV² (1 + cos q)
Force exerted by a jet in its direction of flow on a curved vane is always greater than that exerted on a flat plate.
Force Exerted By a jet on a Hinged Plate

•  Force due to jet of water, normal to the plate
  P_n = ρaV² sin (90º –θ) 
• For equilibrium of plate