Lv 6

# fluid power

solution:

how do you get this equation??

thanks~

rate of "work done on moving from A to B"

why do you multiply the

force at A and the velocity at A?

the area and velocity are different

at points between A and B

also, is the pressure at any point between

A and B the same?

if yes, what is the pressure at point between A

and B ???

Rating
• AAA
Lv 4

Consider the forces at X and Y be Fx and Fy.

Fy is in the opoosite direction of Fx at Fy opposes the motion of fluid.

Let Pressure at X and Y be Px and Py.

Px = Fx / Ax => Fx = PxAx

Py = Fy / Ay => Fy = PyAy, A is the area

As the volume of fluid leaving X is same as the volume of fluid entering Y,

Work done at X

= Fx*x1 (x1 is the displacement caused by force Fx)

= PxAx*x1 = PxV , V is the volume of fluid displaced.

Similarly, work done at Y = -PyV (opposes the motion)

Rate of total work done

= (Px-Py) V / t , t being the time

= (Px-Py) Ax* x1/t

= (Px-Py) Ax*vx, v being the velocity at X.

Source(s): /