Multifunctional Laser System for 1D and 2D Imaging Diagnostic for High-Enthalpy Test Facilities

There is an unsatisfied demand for instrumentation with capabilities for nonintrusive, accurate direct measurements of transport and thermodynamic parameters in the high-speed flow, hyperthermal environment of NASA Arc Jet Complex facilities. Atomic and molecular-based optical diagnostics have been demonstrated to provide unprecedent insight into the dynamics and transport phenomena of reactive and non-reactive flows at spatio-temporal scales inaccessible to traditional (mostly intrusive) flow probes. High repetition rate femtosecond (fs) lasers and high-speed imaging systems have equipped them with new capabilities and new laser-based diagnostics have emerged. However, no single measurement technique can capture and quantify all the phenomena and variables of interest over a wide range of operational conditions.nbsp;We will develop and deliver a mobile multifunctional optical diagnostic platform for non-intrusive, quantitative imaging of relevant gas parameters in arc driven and other high enthalpy ground testing facilities. The platform is powered by a single fs laser and implements and integrates three state-of-the art optical diagnostic techniques: Two Photon Absorption Laser Induced Fluorescence (TALIF), a coherent anti-Stokes Raman scattering (CARS) and Femtosecond Laser Electronic Excitation Tagging (FLEET). The core laser system enables kHz rate nonintrusive measurements of species density, nonequilibrium temperature and velocity. Multiple measurements can be achieved at reduced implementation and operational costs. Such direct experimental data are essential for validating predictions, and for the design and testing of thermal protection systems.