Infrared camera image of an airfoil equipped with an anti-icing system, mounted in the Icing Research Tunnel at NASA’s Glenn Research Center.
Flow temperature and surface temperature measurements can be very important to aerodynamics testing, and have even greater importance in propulsion research. Fluid properties (including viscosity and speed of sound) are dependent on temperature. The stagnation (total) temperature indicates general operating conditions as a key variable in relating test cell characteristics to particular flight conditions.
Surface temperatures can indicate flow properties in a similar way as surface pressures do, and become particularly important at hypersonic speeds and when examining reentry effects. Changes in surface temperature may also be indicative of other flow characteristics, such as a transition from laminar to turbulent flow.
