Calculation of Unsteady Aerodynamic Loads Using Fast-Response Pressure-Sensitive Paint

Ames Research Center, Moffett Field, CA

Raw camera view from uPSP high-speed camera. (Image: NASA)

Many important physical problems in aero-sciences involve unsteady, separated flows. The ability to measure and compute these flows has been a persistent challenge. Unsteady aerodynamics leads to unsteady loads which ultimately decrease system performance and shortens the system lifetime. Currently, dynamic pressure transducers are used to study unsteady flow in wind tunnel tests, which are expensive and do not provide accurate integrated unsteady loads on a wind tunnel model.

NASA Ames has developed a new state-of-the-art method for measuring fluctuating aerodynamic-induced pressures on wind tunnel models using unsteady Pressure Sensitive Paint (uPSP). The technology couples recent advances in high-speed cameras, high-powered energy sources, and fast response pressure-sensitive paint.

The unsteady pressure-sensitive paint (uPSP) technique has emerged as a powerful tool to measure flow, enabling time-resolved measurements of unsteady pressure fluctuations within a dense grid of spatial points on a wind tunnel model. The invention includes details surrounding uPSP processing.

This technique enables time-resolved measurements of unsteady pressure fluctuations within a dense grid of spatial points representing the wind tunnel model. Since uPSP is applied by a spray gun, it is continuously distributed. With this approach, if the model geometry can be painted, viewed from a camera, and excited by a lamp source, uPSP data can be collected. Unsteady PSP (uPSP) has the ability to determine more accurate integrated unsteady loads.

NASA is actively seeking licensees to commercialize this technology. Please contact NASA’s Licensing Concierge at This email address is being protected from spambots. You need JavaScript enabled to view it. or call at 202-358-7432 to initiate licensing discussions. For more information, visit here  .