A fluid is placed in the area between two parallel plates. The upper plate is movable and
connected to a weight by a cable at shown. Calculate the velocity of the plate for three cases.
Assume the fluid to be linseed oil. Assume the fluid to be water. Assume the fluid to be grease
having tau 0 = 4 N/m2 and mu = 0.004 N.sec/m2. In all cases take m = 0.001 kg, delta y = 5
mm. g = 9.81 m/sec2, and the area of contact A-0.5 m2. Assume that steady state is achieved.
Solution
For case 1 and 2, Simple formula can be used to calculate the velocity.
F/A = * Velocity gradient = * (V/y) ; [F=force = m*g, A=area]
=> V = (F * y)/(A * ).......(1)
For case 3, Subtract the value of o from force before putting it in the equation (1). This minimum
force is required for the plate to move, then the normal case continues.
connected to a weight by a cable at shown. Calculate the velocity of the plate for three cases.
Assume the fluid to be linseed oil. Assume the fluid to be water. Assume the fluid to be grease
having tau 0 = 4 N/m2 and mu = 0.004 N.sec/m2. In all cases take m = 0.001 kg, delta y = 5
mm. g = 9.81 m/sec2, and the area of contact A-0.5 m2. Assume that steady state is achieved.
Solution
For case 1 and 2, Simple formula can be used to calculate the velocity.
F/A = * Velocity gradient = * (V/y) ; [F=force = m*g, A=area]
=> V = (F * y)/(A * ).......(1)
For case 3, Subtract the value of o from force before putting it in the equation (1). This minimum
force is required for the plate to move, then the normal case continues.
