Aero-thermal properties of gaseous flows by filtered Rayleigh scattering velocimetry

Abstract

The laser-optical measurement of flow velocity typically relies on techniques, which infer their measured signal by adding tracer particles to the flow. Despite the successful application of techniques like LDA, PIV, or DGV over the past decades, certain flaws such as window contamination by seed particles (resulting in reduced testing periods) or the provision of homogeneous seeding concentrations are still persistent. In this regard, the molecular scattering based filtered Rayleigh scattering (FRS) technique may prove a viable option. For the first time in the literature, an FRS velocimeter is reported, which has the capability to simultaneously acquire time-averaged pressure, temperature as well as three-component velocity fields.