How do i relate pressure drop with h ?

[l2krence]

How do i relate pressure drop with "h"?

http://www.2shared.com/document/L4fH2kdT/HES_2340_Assignment_1.html

Homework Statement

Hi,
Regarding to the link above,
I have a question on my homework on Q2 and Q4. In Q4, What pressure shall i consider in this situation? Shall i include the P,atm? I know there's 1.334N from top and shall i convert this to pressure?
And related it to shear stress?

For the velocity distribution. How do I use Navier-Stroke Equation on here to get the velocity diagram to see whether it's a laminar flow or turbulent flow.

Homework Equations

Shear stress = viscosity x velocity profile
Pressure = Force/Area

The Attempt at a Solution

I want to sketch a velocity in Q2 and relate the pressure drop with clearance height,h includes the Length of cylinder and weight of piston.

 

[jbsteele]

For the Pressure, you can calculate it using the equation Pressure = Force/Area, where the Force is the 1.334N from the top and the Area is the cross sectional area of the cylinder. For the shear stress, you can use the equation Shear Stress = viscosity x velocity profile. The viscosity can be obtained from the table in the link and the velocity profile can be calculated using the Navier-Stokes equations. Once you have the velocity profile, you can then determine if the flow is laminar or turbulent depending on the Reynolds number.