Sutherland's equation is a useful model for the temperature dependence of the viscosity of gases. I give a few details about it in this post: https://curiosityfluids.com/2019/02/15/sutherlands-law/ The law given by: $latex \mu=\mu_o\frac{T_o + C}{T+C}\left(\frac{T}{T_o}\right)^{3/2}&s=1$ It is also often simplified (as it is in OpenFOAM) to: $latex \mu=\frac{C_1 T^{3/2}}{T+C}=\frac{A_s T^{3/2}}{T+T_s}&s=1$ In order to use these equations, … Continue reading Solving for your own Sutherland Coefficients using Python
Category: CFD from Scratch
Establishing Grid Convergence
Establishing grid convergence is a necessity in any numerical study. It is essential to verify that the equations are being solved correctly and that the solution is insensitive to the grid resolution. Some great background and details can be found from NASA: https://www.grc.nasa.gov/WWW/wind/valid/tutorial/spatconv.html First, here is a summary the equations and steps discussed here (in case … Continue reading Establishing Grid Convergence
Numerical Solution of the Compressible Laminar Boundary Layer Equations
In this post I go over the numerical solution to the compressible boundary layer equations. This is very useful when a quick estimate of shear stress, wall heat flux, or boundary layer height if necessary. The sections of this post are: Introduction Compressibility transformation Using the general parabolic form Numerical solution using Crank-Nicolson Results and comparison … Continue reading Numerical Solution of the Compressible Laminar Boundary Layer Equations
Solving the cavity flow problem using the streamfunction-vorticity formulation
The classic lid-driven cavity flow problem is solved using the vorticity streamfunction formulation and compared to a solution using OpenFOAM.