Speaker
Description
Abstract file attached
Summary
The acquisition of laser, detector, optical, mechanical, and electronic hardware has supported the ongoing development and application of sensor strategies for the time-resolved measurement of species concentrations, state populations, and non-equilibrium gas temperatures within the NASA Ames Electric Arc Shock Tube (EAST) facility using tunable diode laser absorption spectroscopy (TDLAS). These measurements provide complementary data to existing emission spectroscopy instrumentation presently in use at EAST, and measurements have been used to help validate kinetic and radiation models applicable to hypersonic flight. TDLAS sensing enables quantitative, high-bandwidth, non-invasive measurements of species, temperature, and velocity in high-speed flow environments. Collaboration with research partners at EAST has extended the measured quantities in these vital ground tests and improved our fundamental understanding of complex hypersonic phenomena. Key scientific advancements from this work have enabled seven new TDLAS diagnostics that probe multiple rovibrational states of CN and NO as well as multiple electronic states of O and N atoms. Furthermore, the rapidly scanned measurements enable extensive comparisons to nonequilibrium simulation, both with NASA software and Stanford developed models. These new measurement strategies have advanced measurement strategies at EAST and uncovered key discrepancies between nonequilibrium models and measurements.
