The Role of Turbulence Intensity and Aerosol Stokes Number in Isokinetic Sampling Techniques

Abstract

Inlet efficiency measurements were made for a range of thin-walled tube sampling probes by comparing them with a probe of fixed size co-located in a uniform aerosol stream with a 10 mph wind velocity. Free-stream turbulence intensity was varied as part of the experimental matrix. The various levels of turbulence intensity were created using classical types of turbulence grids and a unique new class of "fractal grids", which are reported to have unique turbulence qualities. In our study, isokinetic sampling did not provide the same aerosol concentration across scales of probe diameter. Inlet efficiency increased with the increasing probe Stokes number. This result was more pronounced for low levels of free-stream turbulence.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2023
Accession Number
AD1190458

Entities

People

  • Daniel Weber
  • Daniel Wise

Organizations

  • United States Army Combat Capabilities Development Command

Tags

Communities of Interest

  • Autonomy
  • Counter WMD
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Flow
  • Aircrafts
  • Computational Fluid Dynamics
  • Flow
  • Fluid Dynamics
  • Fluid Flow
  • Free Stream
  • Guidance
  • Measurement
  • Particle Size
  • Particles
  • Reynolds Number
  • Statistical Analysis
  • Test And Evaluation
  • Test Facilities
  • Tubes
  • Turbulence
  • Unmanned Aerial Systems
  • Unmanned Aerial Vehicles
  • Wind Tunnel Tests
  • Wind Tunnels
  • Wind Velocity

Fields of Study

  • Environmental science

Readers

  • Aerosol Science/Aerosol Physics
  • Fluid Mechanics and Fluid Dynamics.