Static flow and Its Application Coulson & Richardson, Chapter 6

Fluids: Statics vs Dynamics

Fluid Statics Basic Principles: Fluid is at rest : no shear forces Pressure is the only force acting What are the forces acting on the block? Air pressure on the surface - neglect Weight of the water above the block Pressure only a function of depth

Section 1: Pressure

Variation of pressure in an compressible fluid (gas) for liquids: r is variable, e.g. for an ideal gas: need to know T=T(z)

case of linear temperature variation: case of uniform temperature: T=To case of linear temperature variation: T=To+bz at z1=0 (sea level) T=To p1=po

Example 2.4 Consider a tank containing mercury, water, benzene, and air as shown. Find the pressure (gauge) over the benzene. If an opening is made in the top of tank. Given SG of mercury, benzene and water are 13.55, 0.879 and 1.00 respectively. Use the density of water equal to 999 Kg/m3

Solution

Example 2.5

Solution

Example: Find PA- PB

Example 2.6 (self study) Find expression of