Laboratory Verification of the Optical Turbulence Sensor (OTS): Particulate Volume Scattering Function and Turbulence Properties of the Flow

Abstract

Our aim is to test a robust and noninvasive measurement of particulate and turbulence for coastal applications. Our goal is an extensive tank validation of the Optical Turbulence Sensor (OTS). This sensor uses a Hartman optical wavefront sensor to determine turbulence characteristics and to characterize the particulate field. In our configuration the wavefront sensor has been able to quantify simultaneously turbulent and particulate scattering for particles larger >50 micrometers. Our laboratory studies were carried out in a well controlled fully turbulent convective tank. The optical measurements have been carried out with a number of neutrally buoyant spherical particles of diameter ranging from between 0.5 and 1000 micrometers. We have three main objectives: Turbulence characterization: in this part of the effort we have compared thermistor (the temperature dissipation rate and the temperature dissipation spectra) and Particle Imaging Velocimetry (PIV) measurements of the turbulent kinetic energy dissipation rate, with concurrent optical OTS measurements of the same variables. Particle field characterization: we have tested a new Volume Scattering Function (VSF) measurement method where we have used a wavefront sensor (OTS) to calculate large particles (particles larger >50 micrometers) VSF. Particle/turbulence interaction: in this part we have carried out simultaneous measurement of the particle VSF, the flow velocity and flow turbulent quantities using OTS. These optical derived parameters were then compared with same parameters obtained using PIV technique (energy dissipation rate, flow speed, flow shear), fast thermistor (temperature dissipation rate, temperature spectra), nephlometer (particle VSF).

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2009
Accession Number
ADA526851

Entities

People

  • Darek J. Bogucki

Organizations

  • University of Miami

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Boundary Layer
  • Equations
  • Flow
  • Flow Fields
  • Fluid Mechanics
  • Kinetic Energy
  • Light Scattering
  • Measurement
  • Particle Flux
  • Particle Size
  • Particles
  • Particulates
  • Scattering
  • Temperature Gradients
  • Turbulence
  • Turbulent Flow
  • Verification

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.