Fluid Mechanics


Drag Equation

 , where:

F = Force due to drag.

 = Density of Fluid (kg/m^3)

v = Velocity (m/s)

A = Cross-Sectional Area (m^2)

C = Drag Coefficient (System Property)

Equation of Motion in Fluids

  is applicable at the boundary layer, where:

u = Velocity in x-direction

v = Velocity in y-direction

 = Kinematic Viscosity (m2/s)

Euler Number

 , where:

Eu = Euler number

p = Pressure (Pa)

 = Density (kg/m3)

v = Velocity (m/s)

Grashof Number

 , where:

Gr = Grashof Number

g = Gravity (m/s2)

 = Coefficient of Thermal Expansion (1/K)

Ts = Surface Temperature (K)

 = Bulk Temperature (K)

Hagen–Poiseuille equation

 , where:

P = Pressure drop in cylindrical tube (Pa)

 = Dynamic Viscosity (Pa*s)

L = Length of Pipe (m)

Q = Volumetric Flow (m3/s)

r = Radius of pipe (m)