Fluid Mechanics


Head Loss

 , where:

f = Darcy Friction Factor (or use Moody Diagram to find)

hf = Head Loss (m)

L = Length (m)

D = Hydraulic Diameter (m)

V = Velocity of Fluid (m/s)

g = Gravity (m/s^2)

Heat Capacity Ratio

 , where:

 = Heat Capacity Ratio is approximately:

  • 1.4 for Oxygen (Natural Gas)
  • 1.7 for Argon
  • 1.4 for Hydrogen
  • 1.3 for Water (Steam)

CP = Heat Capacity at a Constant Pressure (J/K)

CV = Heat Capacity at a Constant Volume (J/K)

Hydraulic Diameter

Used to obtain the diameter of non-circular pipes:

 , where:

DH = Hydraulic Diameter (m)

A = Cross-Sectional Area (m^2)

P = Wetted Perimeter (m) (Perimeter exposed to flow)

Hydrostatic Pressure

 , where:

p = Pressure (Pa)

 = Density of Fluid (kg/m3)

g = Gravity (m/s2)

h = Depth (m)

Impact Pressure

 , where:

Pt = Total or Stagnation Pressure (Pa)

P= Static Pressure (Pa)

 = Heat Capacity Ratio

M = Mach Number