Optimization of the Aerodynamics Airfoils Placed in Supersonic Viscous Flow


Nowadays the efficiency of aerodynamics profiles placed in a supersonic flow represents a permanent goal of the human civil transportation or military equipments. Present paper intends to present an optimization method of their shapes, taking into account the Navier-Stokes flow equations, applied for thin layers. Generally, in supersonic flow, the cross-sections of the wings are thin profiles, sym-metric as to reduce the drag force coefficient and maximize the lift coefficient. It is presented a method of the shape cal-culation for aerodynamic profiles with small curvature, based on integral equations Fredholm of the second kind, with a good behavior in the supersonic flows. Some aspects referring to the unsteady flows and air compressibility are also mentioned. There were selected four aerodynamic air-foils with characteristics dedicated to high velocities, with different characteristics, having as main purpose the identi-fication of essential aspects needed to be considered in the numerical modeling. From these four profiles, two are de-duced by theoretical assessments, and two are special known as super-sonic aerodynamic profiles. They were first tested into a subsonic wind channel for incidences between 00 – 40 at different values of wind velocity and secondly into a su-personic wind tunnel, at same incidences, as to better ana-lyze the main factors who influence the aerodynamic of shapes curvature and to assure an optimization of their be-havior. The purpose of testing these profiles was to improve the main characteristics, especially into the trailing and leading edges. The effect of the angle of attack, the influence of velocity and viscosity, the shape curvature on the vortex development were also considered. The obtained results assure a better functioning in the supersonic flow regime, eliminating the adverse pressure gradient and the boundary layer separation, assuring an optimum behavior. Finally are mentioned some conclusions and references. images