There is considerable interest in measurements of unsteady pressure for the study of shock wave boundary layer interactions, flow control, landing bay acoustics, and wing buffet. The proposed fast PSP system would give NASA and their test bed aircraft programs the ability to acquire continues distributions of unsteady pressure in flight using a sensor that can be sprayed onto a model and interrogated optically. This measurement capability is of interest to NASA programs such as the Subsonic Fixed Wing and Environmentally Responsible Aviation programs. SBLI impacts aircraft performance at transonic Mach numbers as the shock induced flow separation can cause buffeting and large-scale lift oscillations that can limit an aircraft's flight envelope. Landing bay acoustics are a significant source of aviation noise and flow control concepts are needed for noise reduction and drag reduction. Each of these applications would benefit from the proposed sensor. The Phase I system would establish the technical capability of the fast PSP system and provide data on the top surface of wings and flaps. The Phase II system would be packaged so that it could be integrated into a region such as the landing bay, and allow regions without optical access to be interrogated. The proposed fast PSP system would improve flight test utilization by allowing the flight test vehicle to be instrumented with unprecedented spatial resolution, and do so without physical modifications to the vehicle.
There is considerable interest in measurements of unsteady pressure for the study of fluid flows such as shock wave boundary layer interactions, flow control, landing bay acoustics, wing buffet, and supersonic inlets. Interest in unsteady pressure measurements in flight spans academic, commercial, and military research. Companies that offer flight testing services, such as Calspan, as well as several commercial aircraft companies such as Cessna, Hawker, and Embraer, have expressed interest in the proposed in-flight fast PSP measurement technology. The proposed fast PSP system would improve flight test utilization by allowing the flight test vehicle to be instrumented with unprecedented spatial resolution, and do so without physical modifications to the vehicle. Evolution of the system into a smaller package that could be mounted on inaccessible regions of the flight test vehicle such as the weapons bay will occur naturally as fast camera imaging technology evolves. This will further extend the commercialization of the technology. This system would enable the investigation of fluid flows at flight conditions, data that will advance the accuracy of numerical models and yield insight into evolving flow control concepts. Furthermore, the demonstration of a productive and validated fast PSP system for flight testing would provide a marketing tool for commercialization of the measurement technology.