Landing Surface Characteristics Unique to V/STOL Aircraft

This article presents work performed at the Naval Air Engineering Center involving V/STOL Aircraft ground flows. Exhaust flows are directly related to aircraft size (thrust level) and propulsion system size (disk loading). A brief commentary on ground flow phenomena through the full range of disk loading is given. Major discussion is devoted to the narrower band of disk loading attendant with high performance V/STOL Aircraft. In particular, gas velocities and temperatures in the ground flow surroundings, and characteristics of pervasiveness are described. Heat transfer into a uniform structure has been calculated for concrete, poly/resin, asphalt, aluminum, and steel. Resultant surface and internal temperature distributions are shown. The Influence of engine exhaust temperature, height above ground, and heating time is illustrated. Jet engine exhaust impingement tests of refractory concretes, asphalt, and aluminum have been conducted and compared with heat transfer computations. Material samples were subjected to afterburning gases at 3150°F and 2.5 atmospheres through prescribed heating and cool down cycles. Materials found capable of with standing such high energy jets are described.