Optimization of Air-breathing Hypersonic Aircraft Design using Euler Codes and Genetic Algorithms

An advanced, modular paneling scheme has been developed for atmospheric flight vehicles with an aim of predicting the drag during hypersonic flight. A generic, three-dimensional grid generation algorithm has been developed for this effort that allows the construction of detailed aircraft geometries using the concept of geometric overlap in three-dimensional spaces. The use of Bernstein polynomials is used to defining the vehicle outer mold line. An automated grid refinement system has been developed that is fully autonomous in operation and converts the user defined grid into the refined grid by trimming the geometrical internal overlaps and generation of high fidelity surface grids over the exposed outer surfaces of the design airframe. A hybrid group of aerodynamic predictive codes using Euler Methodology for Finite Difference Based fluid dynamic systems has been created to determine the aerodynamic loads on the three dimensional airframe. The use of this aero-predictive system allows for the evaluation of detailed distributions of pressure and velocity over the airframe surfaces. Models have also been added for the determination of skin friction over the exposed surfaces using panel interaction schemes. The results for this preliminary design level drag prediction code have been found to be extremely encouraging in their compatibility to the experimental and flight test data.