Theoretical Studies of Configurations Having High Lift-to-Drag Ratios in the Viscous Interaction Regime

摘要

Work was performed to organize theoretical methods for studying aerodynamic components to obtain configurations having high lift to drag ratios in the 150 to 250 Kft altitude range. The main part of the work was devoted to preparing the computational tools needed to develop a two-dimensional wing profile using an inverse approach, i.e., evolving the profile from the desired pressure distribution. Since approximate engineering methods were found insufficient, three computer programs were developed or adapted. They are: two inverse characteristics programs, one with and one without imbedded shocks; a boundary layer program suited to hypersonic, near separation situations; and an accurate blunt body program. With these tools, it is possible to predict the whole flow field, inviscid and viscous, over the nose (in a direct manner) and over the rest of the profile (in an inverse manner). Various difficulties encountered in developing these tools are reported in detail. The other part of the work was an analytical study of the flow at junction of a wing and a fin. (Author)