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 … Continue Reading Establishing Grid Convergence

The Ahmed body is a geometric shape first proposed by Ahmed and Ramm in 1984. The shape provides a model to study geometric effects on the wakes of ground vehicles … Continue Reading The Ahmed Body

In this post I am going to simulate an oscillating cylinder in a cross-flow… just for fun… and to provide an additional tutorial case for those wishing to use some … Continue Reading Oscillating Cylinder in Laminar Crossflow – pimpleDyMFoam

Careful selection of TVD interpolation schemes is important for solving high speed compressible flows. In cases with discontinuities such as shockwaves and contact surfaces, these schemes help keep the simulations free of … Continue Reading Shocktube – rhoCentralFoam TVD Schemes Test

Recently I read a CFD Online forum post where the accuracy of rhoCentralFoam was called into question. The test case was the simple example of a converging diverging nozzle flow. … Continue Reading Converging-Diverging Nozzle v2- rhoCentralFoam

Here, I am going to go over the solution to fully developed laminar pipe flow. This is a canonical problem and provides an exact solution to the Navier-Stokes equations. It … Continue Reading Hagen-Poiseuille flow

In this post I am going to go through the solution to the moving wall Couette flow problem. An illustration of the problem is given below: In this problem, the fluid … Continue Reading Couette Flow (Moving Wall)

Deriving the speed of sound is a main component of any undergraduate textbook in gas dynamics and is very important to understanding more complicated concepts! Here, I will give an honest … Continue Reading Definition of the Speed of Sound

An excellent test case, and case to familiarize yourself with some of the turbulence models available in OpenFOAM is a 2D flat plate with zero pressure gradient. I will solve … Continue Reading Turbulent Zero Pressure Gradient Flat Plate – simpleFOAM, komegaSST

I have already done a post on supersonic flow over 23 degree wedge. In that post, we were intentionally creating a situation where the shock wave would be detached from the … Continue Reading Alternate Set-up: Oblique Shock in rhoCentralFOAM

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 … Continue Reading Numerical Solution of the Compressible Laminar Boundary Layer Equations

In this post I am going to derive the compressible Euler equations: (1) (2) (3)

In this post I go over the theory of oblique shocks by building on our understand of normal shockwaves! I will give a short overview of the theory and strategy … Continue Reading Oblique Shockwaves

In this post I will go over the set up and solution of a pressure driven nozzle flow with a shock located in the diverging section. This refers to the … Continue Reading Pressure Driven Nozzle Flow with Shock – rhoCentralFoam

In this post I will simulate inviscid Mach 1.5 flow over a 23 degree wedge of a finite height.

Here I have written a Matlab App for calculating compressible aerodynamics using the basic gas dynamics equations. The calculations available are: Isentropic Flow (including Prandtl-Meyer flow) Normal Shocks (See article) … Continue Reading Compressible Aerodynamics Calculator – Matlab