Comparison of Split-Film and X-Film Measurements in 2-D Flow
Abstract
The purpose of these experiments was to compare turbulence measurements using two types of velocity measurement probes: split-film and x- film. The goal is to determine the turbulent flow regimes where the split-film can be used to replace the x-film. The split-film sensor is composed of two independent films supported by a quartz filament. The split-film's larger diameter makes it less sensitive to high frequency fluctuations than the x-film, but is able to measure higher flow angles than the x-film. The objective of this thesis is to compare turbulence measurements of the split-film with the more established x-film over a range of turbulence levels. Results indicate problems using the split-film in regions of low velocity combined with low turbulence (Reynolds number based on film diameter less than 380 and turbulence intensity below 1.5%). The split-film provided better turbulence measurements than the x- film when used in regions of high turbulence (10 to 50%) with velocity fluctuations greater than 45 deg from the mean. The split-film is not capable of detecting flow reversals, but will give the proper direction of the velocity component normal to the split. This information is helpful because the magnitude of the Reynolds shear stress in reversing flow can still be determined using the split-film, but not the direction (sign). Keywords: Hot film anemometry, Hot wire anemometry. Theses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1988
- Accession Number
- ADA206023
Entities
People
- Timothy E. Fisk
Organizations
- Air Force Institute of Technology