NASA aero-science ground test facilities, including transonic, supersonic and hypersonic wind tunnels, provide critical data and fundamental insight required to understand complex phenomena and support the advancement of computational tools for modeling and simulation. In these facilities, real-time, high-repetition-rate (10 kHz–1 MHz) 2D or 3D measurement techniques are needed to track the high-speed turbulence dynamics. Current state-of-the-art measurement capabilities in harsh wind tunnelenvironments are effective but limited to sample rates of 10 hertz, which is insufficient to track the dynamic of the turbulent reacting and non-reacting flows. This proposal offers an integrated package of truly cutting-edge, high-repetition-rate (up to 1 MHz rate), narrow-linewidth, burst-mode Optical Parametric Oscillator (OPO) system for multi-species laser induced fluorescence (LIF) detection in NASA ground test facilities. The concepts and ideas proposed are ranging from proof-of-principles demonstration of novel methodologies using a pulse-burst laser pumped OPO system for multi-parameter measurements (density, temperature, species concentration, and flow visualization, etc.) in realistic tunnel conditions. The proposed high-repetition-rate OPO-based LIF technique which is suitable for 2D and 3D multi-parameter measurements is a state-of-the-art technique for analysis of unsteady and turbulent flows.
The proposed research effort will provide new instrumentation capabilities and methodologies, together with a convenient and user-friendly software package for the burst-mode OPO system control, data analysis and interpretation, for tracking turbulence evolution that is required as inputs to model and predict complicate turbulence flow behavior in NASA supersonic and hypersonic large-scale wind tunnels.
The high-speed OPO and PLIF system could also be applied in various large test facilities in many universities, research institutes and aviation companies for accurate flow and combustion measurements. Potential customers could be from research facilities in DoD, DARPA, DOE, and companies, such as SpaceX, Blue Origin, GE, Pratt-Whitney, and other industrial aerospace interests.