Gas Surface Interaction Reactant and Product Characterization in High Enthalpy Air Plasma Flows via nsTALIF/LIF Imaging in the UIUC 350 kW Plasmatron X Facility

In this work, experimental and numerical efforts to determine radial temperature and density distributions of reactant and product species above reactive copper samples of varied geometries in the 350 kW Plasmatron X facility operating an air plasma are presented. Experimental approaches made use of spectrally resolved nanosecond two-photon and single photon absorption laser-induced fluorescence (nsTALIF and nsLIF) imaging strategies to extract radial distributions of reactants (O atoms and N atoms) and products (NO). These radial beam images were acquired at various locations, spanning from the boundary layer edge to the sample surface, with sufficient spatial resolution to capture critical sub-millimeter temperature and species density gradients near the material surface. Latest results have shown a level of agreement that have helped guide in-house CFD development and validation efforts capable of modeling facility physics from the induction zone to the material surface.