Progress in molecular based thermometry and velocimetry for the ZBOT experiment*

We report on our progress in the development of whole-field molecular based optical techniques for velocimetry and thermometry in the NASA Zero Boil-off Tank (ZBOT) experiment. ZBOT is a small-scale experiment aimed at study of heat transfer and phase change of cryogenic fluids under microgravity condition. The experiment on the International Space Station uses a transparent  simulant fluid, Perfluoropentane (PnP), a saturated fluorocarbon with unique physical properties that make application of optical diagnostic methods challenging. We present the feasibility of molecular tagging velocimetry (MTV) and Laser Induced Fluorescence (LIF) thermometry in PnP medium. Results of single component velocimetry and planar thermometry are shown in a simple ground test experiment involving the discharge of a hot/cold PnP jet into ambient PnP fluid.