auxi.tools.transportphenomena.dimensionlessquantities module

This module provides functions to calculate dimensionless quantities used when doing transport phenomena calculations.

auxi.tools.transportphenomena.dimensionlessquantities.Gr(L: float, Ts: float, Tf: float, beta: float, nu: float, g: float)

Calculate the Grashof number.

Parameters:
  • L – [m] heat transfer surface characteristic length.
  • Ts – [K] heat transfer surface temperature.
  • Tf – [K] bulk fluid temperature.
  • beta – [1/K] fluid coefficient of thermal expansion.
  • nu – [m2/s] fluid kinematic viscosity.
Returns:

float

\mathrm{Gr} = \frac{g \beta (Ts - Tinf ) L^3}{\nu ^2}

Characteristic dimensions:
  • vertical plate: vertical length
  • pipe: diameter
  • bluff body: diameter
auxi.tools.transportphenomena.dimensionlessquantities.Nu(L: float, h: float, k: float) → float

Calculate the Nusselt number.

Parameters:
  • L – [m] heat transfer surface characteristic length.
  • h – [W/K/m2] convective heat transfer coefficient.
  • k – [W/K/m] fluid thermal conductivity.
Returns:

float

auxi.tools.transportphenomena.dimensionlessquantities.Pr(nu: float, alpha: float) → float

Calculate the Prandtl number.

Parameters:
  • nu – [m2/s] fluid kinematic viscosity / momentum diffusivity.
  • alpha – [m2/s] fluid thermal diffusivity.
Returns:

float

auxi.tools.transportphenomena.dimensionlessquantities.Ra(L: float, Ts: float, Tf: float, alpha: float, beta: float, nu: float) → float

Calculate the Grashof number.

Parameters:
  • L – [m] heat transfer surface characteristic length.
  • Ts – [K] heat transfer surface temperature.
  • Tf – [K] bulk fluid temperature.
  • alpha – [m2/s] fluid thermal diffusivity.
  • beta – [1/K] fluid coefficient of thermal expansion.
  • nu – [m2/s] fluid kinematic viscosity.
Returns:

float

Ra = Gr*Pr

Characteristic dimensions:
  • vertical plate: vertical length
  • pipe: diameter
  • bluff body: diameter
auxi.tools.transportphenomena.dimensionlessquantities.Re(L: float, v: float, nu: float) → float

Calculate the Reynolds number.

Parameters:
  • L – [m] surface characteristic length.
  • v – [m/s] fluid velocity relative to the object.
  • nu – [m2/s] fluid kinematic viscosity.
Returns:

float

auxi.tools.transportphenomena.dimensionlessquantities.Sh(L: float, h: float, D: float) → float

Calculate the Sherwood number.

Parameters:
  • L – [m] mass transfer surface characteristic length.
  • h – [m/s] mass transfer coefficient.
  • D – [m2/s] fluid mass diffusivity.
Returns:

float