Description: Ground-based testing resources are essential for the development of aerospace systems. While these facilities can be expensive to maintain and operate, the cost to acquire data can be significantly reduced by implementing measurement systems featuring high data capture per test while requiring limited modification or instrumentation of models. There has recently been a significant upturn in the use of fast responding Pressure-Sensitive Paint (PSP) technology. Fast PSP, which offers a means of acquiring unsteady pressure data at millions of locations on a model surface, has long been viewed as a disruptive technology. Recent advancements in fast CMOS camera and LED technology have facilitated the realization of this long promised capability. Data at an individual pixel can be extracted and processed as traditional pressure tap data to identify mean, rms, and spectral content and full data sets can be decomposed spectrally to present the amplitude of the pressure fluctuations spatially at a series of frequencies. Acquisition of the data is only one portion of an effective fast PSP system. Fast PSP systems generate thousands of images in seconds, and each of these images represents a sample of up to one million fast pressure sensors. For maximum productivity, the data must be collected, processed, and a preliminary analysis conducted in near real-time to allow users to identify flow features of interest, and modify the test plan to maximize tunnel test time. The data processing tools must include fast processing of the data and automated analysis tools to identify key flow features in near real-time. The objective of the Phase I and Phase II program is to both identify the fast PSP hardware for a large wind tunnel system, and develop and integrate the data processing tools that will result in a productive system. The proposed fast PSP system would improve wind tunnel utilization, enhance the performance of ground-based programs, and indirectly lower operational costs

Benefits: There is considerable interest in measurements of unsteady pressure for evaluation of computational models and study of flow physics on hypersonic inlets, compressors, aeroelasticity, and rotorcraft aerodynamics. The ability to acquire data from one million fast responding pressure transducers sprayed onto a model is a technological capability that is of interest to a variety of research wind tunnels, for example the TDT and Ames 11-foot tunnel. This proposal will provide advancement of the state-of-the-art in this field as the proposed research will develop a system that includes near real-time data presentation and data mining tools will improve productivity by allowing users to focus test resources on key flow features. The fast PSP technology could be deployed to wind tunnels at different NASA centers for testing on a variety of programs that have need of unsteady pressure measurements. The proposed fast PSP system would improve wind tunnel utilization, enhance the performance of ground-based programs, and indirectly lower operational costs. The installation of a productive fast PSP system would provide a marketable capability that could drive customers to the NASA facilities

Fast pressure-sensitive paint systems is under investigation for a variety of applications in aerodynamics. This program will provide advancement of the state-of-the-art in this field as the proposed research will develop a system for the measurement of continuous distributions unsteady pressure that require no physical modifications to the model and produces data with high spatial resolution. The addition of the near real-time data presentation and data mining tools will improve productivity by allowing users to focus test resources on key flow features. The final product of this program would be a very marketable system that should be of interest to both military and commercial wind tunnel facilities. The proposed fast PSP system would improve wind tunnel utilization, enhance the performance of ground-based programs, and indirectly lower operational costs. The installation of a productive fast PSP system would provide a marketable capability for any commercial wind tunnel customer