Accession Number:

ADA526851

Title:

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

Descriptive Note:

Research rept.

Corporate Author:

MIAMI UNIV FL ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE

Personal Author(s):

Report Date:

2009-01-01

Pagination or Media Count:

9.0

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. Particleturbulence 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.

Subject Categories:

  • Test Facilities, Equipment and Methods
  • Optical Detection and Detectors
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE