LAMINARIZATION OF BOUNDARY-LAYER UNDER CONDITIONS OF NEGATIVE-PRESSURE GRADIENT AND SURFACE HEATING

The possibilities of improving the aerodynamic characteristics of the profile owing to combination laminarization, including the optimizatio n of distribution of pressure and surface temperature, are investigate d. The surface temperature distribution range is treated, which corres ponds to heating the nose and cooling the rest of the profile to the f orward flow stagnation temperature. It is shown that one can (a) incre ase the profile lift coefficient at constant drag, and (b) reduce the drag and increase the critical Mach number at constant lift. Examples are provided which demonstrate that the heating of a part of the wing surface in combination with other methods of laminarization may lead t o an energetically favorable reduction of drag.