Prediction of Turbulent Skin Friction for Two-Dimensional, Rib-Type Surface Roughness Using a Discrete Element Approach.

Abstract

A discrete element model for turbulent flow over two-dimensional rib-type roughness is developed and validated. Surface roughness blockage effects and form drag are included as a constituent part of the differential equations. Separation and reattachment of the flow over rib roughness are identified as the dominant flow phenomena, and models are developed which incorporate the separated region geometry into the blockage. The form drag model is based on the pressure difference between the windward and leeward forces of the roughness. Predictions are compared with a variety of data sets. These comparisons indicate that the discrete element approach can be successfully applied for rib-type roughness. However, the model has a more narrow range of application for different surface geometries than the very broad range which has previously been demonstrated for three-dimensional, distributed roughness. Keywords: Two-dimensional roughness; Rib roughness; Boundary layer.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1985
Accession Number
ADA163165

Entities

People

  • B. K. Hodge
  • Hugh W. Coleman
  • Robert P. Taylor

Organizations

  • Mississippi State University

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aeronautical Laboratories
  • Air Force
  • Air Force Facilities
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Data Sets
  • Differential Equations
  • Equations
  • Experimental Data
  • Fluid Flow
  • Geometry
  • Skin Friction
  • Surface Roughness
  • Three Dimensional
  • Turbulent Flow
  • Two Dimensional

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Structural Dynamics.