Surface Roughness Effects in Low Reynolds Number Channel Flows (POSTPRINT)

Abstract

Rarefied helium and nitrogen flow expanding into vacuum through 150 micron high and 1.5 cm long channels is studied experimentally and numerically with the DSMC method. Different types of channel walls are examined, both polished and rough with well characterized roughness shaped as triangles and rectangles. The pressure varies from 200 to 13,000 Pa, with the gas mean free path being both much larger and much smaller than the roughness size of about 20 micron. A conical surface roughness model applicable for the DSMC method is proposed. An expression relating this model to the Cercignani-Lampis scattering model is derived. Good agreement between the numerical and experimental results is observed for the rough walled channel.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 2006
Accession Number
ADA473047

Entities

People

  • A. Ketsdever
  • I. Wysong
  • Jessie Duncan
  • N. Gimelshein
  • S. Gimelshein
  • T. Lilly

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Channel Flow
  • Distribution Functions
  • Gas Dynamics
  • Gas Flow
  • Knudsen Number
  • Mach Number
  • Mass Flow
  • Mean Free Path
  • Measurement
  • Monte Carlo Method
  • Rarefied Gas Dynamics
  • Roughness
  • Scattering
  • Stagnation Pressure
  • Surface Roughness
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering