Versatile Sensor for Transition, Separation, and Shock Detection

The proposed innovation is a simple, robust, sensor array for the detection of laminar/turbulent transition location, areas of flowfield separation, and shock wave locations. The system can be used in both ground and flight test facilities. The proposed system uses a very robust and proven sensor technology combined with a novel mounting and manufacturing technique. The sensor array is reusable and can be produced in a configuration that requires no external power, acquisition or viewing, for flight test applications. The system combines an array of small, surface flush, sensors embedded in an extremely thin, flexible polyimide strip. The system operates by sensing changes in local heat transfer within the boundary-layer. Variations in heat transfer coefficients due to the state of the boundary layer (laminar, transitional, turbulent, separated regions) produce changes in the sensor output. Other flowfield features where heat transfer is affected will also be discernable, such as shock waves. The flush mounted sensors, embedded in a smooth, thin polyimide sheet, conform to the local surface contour and produce minimal aerodynamic interference, allowing non-intrusive measurements. The system will be quantitatively accurate across the low-speed through supersonic flow regime. After testing, the system can be quickly removed and reused. Compared to current systems designed for similar measurements, the proposed system promises to provide a significantly more robust and efficient system in a relatively simple, cost effective package.