Development of Filtered Rayleigh Scattering Velocimetry for Wind Tunnel Application.
Abstract
THIS REPORT DEVELOPED UNDER SBIR CONTRACT The goal of this SBIR program was to develop a FRS (filtered Rayleigh scattering) velocimetry instrument for the study of unsteady flow fields. During Phase I we constructed a single-velocity-component device for use with a single-mode Q-switched Nd:YAG laser. This ERS device included a custom wavemeter for recording accurately the laser wavelength on each pulse, two 16-bit, back-illuminated CCD cameras, and custom Windows-95 software for integrating the wavemeter and cameras. Initially, we tested and debugged the FRS system using a supersonic (Mach 1. 36) axisymmetric jet. These tests demonstrated that accurate mean (within 5%) and instantaneous (within 4%) velocities can be obtained with this technique. Subsequent to these tests, we implemented the FRS velocimetry instrument in the SARL (Subsonic Aerodynamic Research Laboratory) wind tunnel to test the feasibility of applying this advanced instrumentation in a realistic large-scale tunnel facility. We investigated the flow over a delta-wing model with and without tail fins; here, the freestream velocity compared well to the value derived from pitot probes, while FRS measurements over the delta wing provided new insight into complex, unsteady flows. Potential applications include the timely and cost-efficient testing of novel aerodynamic concepts and designs in large-scale wind tunnels.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1998
- Accession Number
- ADA359849
Entities
People
- C. D. Carter