Aerodynamic/Acoustic Splitting Technique for Computation Aeroacoustics Applications at Low-Mach Numbers

The Multiple Pressure Variables Method for Fluid Dynamics and Aeroacoustics at Low Mach Numbers

The incompressible limit of a compressible fluid, when the Mach number tends to zero, is a singular limit due to the fact that the governing equations change their type. The propagation rate of the pressure waves become infinite. Based on asymptotic results the multiple pressure variables (MPV-) method is reviewed as it may be used for the construction of numerical methods in this low Mach numb...

Direct Numerical Aeroacoustics for Low Mach Numbers Using One Unstructured Grid

Using an unstructured grid, for which the mesh size is adapted to the local flow and acoustic solution, one can reduce the number of unknowns needed for a direct aeroacoustic simulation. The compressible Navier-Stokes equations for Mach numbers 0 < M < 1 are considered. However, the unstructured grid together with the increasing stiffness of the problem for M → 0 reveals new numerical challenge...

Entropy Splitting for High Order Numerical Simulation of Vortex Sound at Low Mach Numbers

A preconditioned solver for sharp resolution of multiphase flows at all Mach numbers

A preconditioned five-equation two-phase model coupled with an interface sharpening technique is introduced for simulation of a wide range of multiphase flows with both high and low Mach regimes. Harten-Lax-van Leer-Contact (HLLC) Riemann solver is implemented for solving the discretized equations while tangent of hyperbola for interface capturing (THINC) interface sharpening method is applied ...

Computation of Airfoils at Very Low Reynolds Numbers

We discuss a new numerical scheme involving adaptive boundary conditions which allows to compute, at very low Reynolds numbers, drag and lift of airfoils with rough surfaces efficiently with great precision. As an example we present the numerical implementation for an airfoil consisting of a line segment. The solution of the NavierStokes equations is singular at the leading and the trailing edg...