Patent — available for licensing
Tailorable Resistance Heating Layer and Silicon Carbide Protective Coating
A NASA invention available to explore as a licensing opportunity.
About this technology
Overview
Aerodynamic testing in cryogenic wind tunnels requires precise detection of laminar-to-turbulent flow transition. The standard approach of creating a surface temperature step by adjusting liquid nitrogen injection is slow, expensive, and can disturb the flow field. Meanwhile, the temperature-sensitive paint (TSP) and coatings applied to test models must withstand temperatures from −250°F to 150°F while maintaining a smooth, damage-free surface. Even durable polyurethane coatings are prone to scratches and divots from debris, water, and oil, which trigger premature flow transition and require daily sanding and polishing between test runs. NASA's Langley Research Center developed two complementary spray-on coatings to address these challenges. The first is a resistive heating layer that applies a thin conductive film to the model surface. Powered through copper-tape electrodes, it generates uniform, localized heat to create a precise temperature step without altering airflow. The second is a protective topcoat that incorporates beta silicon carbide fibers into a polyurethane binder, doubling scratch resistance compared to standard polyurethane. Applied over the heating layer, it protects against debris damage while preserving the smooth finish required for TSP and infrared thermography.