Determining Optimum Conditions For Dual Time Stepping Using Convergence Acceleration Techniques in Computational Aeroacoustics

Open Access
Author:
Rout, Vikram
Graduate Program:
Aerospace Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
December 15, 2014
Committee Members:
  • Philip John Morris, Thesis Advisor
Keywords:
  • DRP
  • Dual Time Stepping
  • Implicit Residual Smoothing
  • Multigrid
Abstract:
Computational Aeroacoustics(CAA) involves a large quantity of complex calculations. Thus like any other computationally intense problems, the computational time and costs are of primary concern. The flow problem in the present thesis consists of a small disturbances superimposed with a uniform mean flow. These disturbances comprise of acoustic, entropy and vorticity waves. Two types of boundary conditions, namely radiation and outflow boundary conditions, are applied to the waves exiting the domain. Low-dispersion, high-efficiency numerical schemes called Dispersion-Relationship-Preserving(DRP) schemes are used for highly accurate numerical results$^{[7]}$. Three different convergence acceleration techniques have been used in this thesis. These are Dual Time Stepping(DTS), Implicit Residual Smoothing(IRS) and Multigrid technique. Each of these convergence acceleration methods have been implemented individually as well as along with the other two methods to determine the most numerically accurate and cost efficient combination of these techniques.