Three-Component Particle Image Velocimetry: Low-speed Jet Measurements and Preparation for Scramjet Combustor Experiments

Abstract

Principles of three-component Particle Image Velocimetry (PIV) and the application of this technique to a low-speed jet are discussed. For this bench-top experiment, the low-speed jet was provided by a 5.97 W centrifugal blower that produced a steady flow of air through a honeycomb structure with an average axial velocity of 7.87 m/sec as measured with a Pitot tube. The axial to cross-plane velocity component ratio was estimated to be 10:1 and flowstraightening was accomplished by way of the honeycomb structure. The three-dimensional velocity field was determined by seeding the flow with oil particles provided by a commercial fogger and performing 3D Particle Image Velocimetry (3D PIV) on the low-speed jet. The average axial velocity as measured with the Pitot tube was later compared to the axial velocity found using the PIV technique. This bench-top experiment was completed in preparation for three-component PIV measurements on the dual-mode scramjet combustor at the University of Virginia. The challenges of employing the 3D PIV technique to this dual-mode scramjet combustor and the work currently underway to facilitate PIV measurements in this situation are discussed.