A pipe and nozzle are attached to a reservoir as shown The i

A pipe and nozzle are attached to a reservoir as shown. The inlet to the pipe is not rounded, nor i the entrance to the final pipe section leading into the nozzle. The radius of curvature of both 90 degree bends is R = 0.06D. The only loss in the nozzle is due to the 60 degree contraction. The friction factor in the pipe is f = 0 0255 when the diameter is D, and f = 0.0200 when the diameter is 5/2 D. Determine the nozzle exit velocity, U, as a function of L and gravitational acceleration, g. Assume alpha = 1 throughout.

Solution

The ratio of L/D is not given, as it is needed in the friction pipe formula:

head loss = f*(L/D)* (V*V)/(2g)

assuming no gain in velocity due to the pipedrop, details of the friction loss are:

a) outlet velocity from reservoir (Vout)^2/2g`= h/rho

loss in first section of pipe: .0255*(L/D)*(h/rho)    (a)

loss due to 90 degree bend from tables, can be put as a factor of 0.9 to the velocity head

thus head after leaving the first bend is 0.9 times (1-(a))

Repeat fro second bend and second section of pipe.

Estimate friction in nozzle of dia 5/2D as above

Finaly velocity is obtained by subtraction of all the losses.