Accession Number:

ADA470860

Title:

Computational Study of Inlet Active Flow Control

Descriptive Note:

Final rept. 6 Feb 2005-11 May 2007

Corporate Author:

HOWARD UNIV WASHINGTON DC DEPT OF MECHANICAL ENGINEERING

Report Date:

2007-05-01

Pagination or Media Count:

11.0

Abstract:

A study was performed using the Air Vehicles Unstructured Solver AVUS to solve internal flow fields for diffusing S-ducts with separated flow. The study examined various boundary conditions, inflow, outflow and initial conditions, and grid sizes. The effort struggled to find an overall setup that agreed well with previously published results on the chosen geometry. In the end, it was discovered that several key issues were the cause. These issues included lack of a refined, structured, boundary layer grid region high CFL numbers and improper boundary conditions. The case was re-run with more appropriate conditions and a grid better suited to capture the boundary layer impact. The key issues encountered are documented here as well as the setup for the successful test case. This study demonstrated the criticality of proper boundary conditions, the benefit of initializing the flow field, and the importance of understanding critical solution health parameters such as y. Additionally, the importance of a well constructed grid has been demonstrated. This is of particular importance for solutions that involve or may potentially involve separated boundary layers. Other parameters that may prove crucial are CFL number and sweeps per iteration.

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE