Luminescence-Based Surface Measurement Technique for Simultaneous Pressure and Temperature Measurements within Non-Oxygen Based Hypersonic Ground Test Facilities

Develop and validate a non-intrusive, luminescence-based surface measurement technique for simultaneous pressure and temperature measurements within non-oxygen-based hypersonic ground test facilities.

Within aerodynamic testing, pressure sensitive paint (PSP) provides crucial global surface pressure data that is utilized in calculating aerodynamic loads [1] and identifying small scale features within the flow. The working principle behind PSP involves luminophores that fluoresce at an intensity inversely proportional to the number of oxygen molecules present i.e., oxygen quenching [2].

While these paints/luminophores have been sufficiently researched, the use-case of these paints is severely limited due to the requirement of oxygen in the flow field. Advanced hypersonic wind tunnels such as the blowdown facility at AEDC Tunnel No. 9 which utilizes nitrogen as the working fluid, are unable to utilize PSP to capture global pressure data with this method and are therefore severely limited to discrete measurement techniques. It is required that a novel technique be developed to capture simultaneous global pressure and temperature measurements in nonoxygen-based hypersonic wind tunnels.

Phase I efforts outline technique/paint development and establish feasibility through thorough characterization of the paint properties/sensitivities and reduction process using benchtop testing and testing within small-scale (educational) supersonic/hypersonic facilities.

Phase II efforts outline full scale prototype demonstrations within a hypersonic test facility through either test probes or full-scale model testing on a well-known/standard test article. The completed technique and refined data reduction process will be delivered at this phase.

The technique can be marketed for non-intrusive simultaneous pressure/temperature measurements in non-oxygen-based high-speed wind tunnels.