Effects of heat transfer on aerodynamics and possible implications for wind tunnel tests

A review is made of the large effects of heat transfer on steady aerodynamics. Cooling the surface delays flow separation and thus is roughly equivalent to an increase in Reynolds number. Conversely heating promotes flow separation and is roughly equivalent to a decrease in Reynolds number. Cooling can also increase the extent of laminar boundary layers. These characteristics might be exploited to identify conditions for which large scale effects occur. The review has found no discussion of the effects of heat transfer on unsteady aerodynamics. From the steady effects some tentative suggestions are inferred about the probable influence of heat transfer on buffet excitation measurements in wind tunnels. Some preliminary wind tunnel tests and some predictive studies are recommended to clarify some of the issues discussed.