Computational Study of Inlet Active Flow Control

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.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 2007
Accession Number
ADA470860

Entities

People

  • Angela Scribben
  • Matthew Goettke
  • Sonya T. Smith

Organizations

  • Howard University

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Aerospace Craft
  • Air Force Research Laboratories
  • Aircrafts
  • Boundaries
  • Boundary Layer
  • Computational Fluid Dynamics
  • Flow
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Geometry
  • Layers
  • Mach Number
  • Propulsion Systems
  • Static Pressure
  • Unmanned Aerial Vehicles
  • Vehicles

Readers

  • Computational Fluid Dynamics (CFD)
  • Economics
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)