Validation of characteristic boundary conditions implemented in computational aeroacoustics large eddy simulations of wall bounded flows

Matthew Edward Louis, Purdue University

Abstract

Continual advancements in computational power have made it possible to conduct, within a reasonable length of real time, accurate aeroacoustic large eddy simulations (LES) of turbulent jets with enough grid points to include the physical nozzle geometry. Moving from a tool that only simulates the free turbulent jet to a tool that can simulate the nozzle and the jet requires introducing an implementation of a viscous wall boundary condition. Characteristic-type boundary conditions are of great interest in computational aeroacoustics because they attempt to properly reflect or absorb the acoustic and entropic waves moving through the boundary. An implementation of characteristic boundary conditions and the application of these conditions to a viscous wall were added to a large eddy simulation tool. Before utilizing the new tool for simulations of a turbulent jet, extensive validation is necessary to ensure that the new boundary conditions are performing correctly and accurately. Three simulations of viscous flow past a circular cylinder were conducted: a quasi-2-D simulation and a 3-D simulation, both at Re = 400, and a 3-D simulation at Re = 3900. All three simulations were compared with other numerical and experimental results. The current simulations agree very well with these other results, especially the Re = 3900 case. The LES tool is shown to produce accurate simulations of these three cases and is thereby validated for use in accurately simulating other exterior flows.

Degree

M.S.A.A.

Advisors

Lyrintzis, Purdue University.

Subject Area

Aerospace engineering

Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server
.

Share

COinS