Compressible flow effects are encountered in numerous engineering applications involving high speed flows and/or flows with large pressure differences, e.g. gas turbines, steam turbines, internal combustion engines, Stirling engines, rocket engines, high-speed aerodynamics, high speed propellers, gas pipe flows, etc. In fact, modern society with its dependence on fast ground and air transportation as well as reliable electricity generation would not function without compressible flow. Special phenomena such as compression shocks, entropy layers, expansion fans, flow-induced noise etc are of fundamental scientific importance and directly affect the performance and endurance of these engineering applications.
Solving the compressible Navier-Stokes equations means that acoustic waves are included in the solution (if the resolution is fine enough and if the accuracy of the numerical scheme is high enough to be able to be able to represent the high-frequency low-amplitude acoustic perturbations). This implies that one can study sound generated by the flow itself - a branch of Computational Fluid Dynamics (CFD) often referred to as Computational Aeroacoustics (CAA).
The design of nozzles for space rocket nozzles is an example of an application where compressible flow simulation are of high value. Testcampaigns for rocket nozzles are extremely complicated and expensive, which means that input from simulations are needed to be able to make desisions in eraly design phases. Moreover, simulations can be used to analyze the nozzle flow at locations and flow conditions where measurements are impossible due to, for example, high temperatures and pressures.
Compressible Computational Fluid Dynamics (CFD) can be used for simulation of compressor stage performance and as data generation tool in a blade shape optimization workflow.
The picture shows a snap shot of the flow field generated when fluid leaves a convergent-divergent nozzle at supersonic conditions. The interaction of turbulence structures and shocks in the supersonic jet can be simulated using Computational Fluid Dynamics (CFD) based on the compressible form of the Navier-Stokes equations. In this specific case, the simulations have been done using Large-Eddy Simulation (LES).
The Compressible Flow course framework is stored and maintained using a private repository at GitHub.