Fluid Dynamics

Dimensionless Numbers

Reynolds Number

indsl.fluid_dynamics.Re(speed: Series, density: float, d_viscosity: float, length_scale: float) → Series

Reynolds Number.

The Reynolds number is the ratio of inertial forces to viscous forces within a fluid subjected to relative internal movement due to different fluid velocities.

Parameters:

speed – Flow speed.
density – Density. Density of the fluid.
d_viscosity – Dynamic viscosity. Dynamic viscosity of the fluid.
length_scale – Characteristic length. Characteristic linear dimension. A characteristic length is an important dimension that defines the scale of a physical system. Often, the characteristic length is the volume of a system divided by its surface.

Returns:

Reynolds number

Return type:

pandas.Series

Friction Factor: Haaland equation

indsl.fluid_dynamics.Haaland(Re: Series, roughness: float) → Series

Haaland equation.

The Haaland equation was proposed in 1983 by Professor S.E. Haaland of the Norwegian Institute of Technology. It is used to directly solve the Darcy–Weisbach friction factor for a full-flowing circular pipe. It is an approximation of the implicit Colebrook–White equation, but the discrepancy from experimental data is well within the accuracy of the data.

Parameters:

Re – Reynolds Number
roughness – Surface roughness

Returns:

Friction factor

Return type:

pandas.Series