Two Dimensional Hypersonic Body-Intake Multi-Object Optimization with NSGA-II Algorithm

Abstract

The forebody/inlet shape of the scramjet engine is significant to airplane performance. A multi-object optimization of hypersonic body-intake configuration is reported in the present work. The optimization system consists of geometry parameterization, mesh deformation, aerodynamic performance evaluation via computational fluid dynamics (CFD) and the top level driving optimization algorithm. In the present work, geometry parameterization is accomplished through B-Spline based free form deformation (FFD) method, volume mesh deformation is computed via inverse distance weight (IDW) method. Aerodynamic performance is evaluated with shear stress transportation model closed Reynolds averaged Navier-Stokes equations. At the top level, optimization is driven by the non-dominated sorting genetic algorithm II (NSGA-II) algorithm. Finally, the present optimization system is applied to a two dimensional hypersonic combined forebody-intake configuration. Numerical result shows that optimization gained improvement of 5% thrust, 9% pressure rise ratio and 7% total mass flow rate, which approved the effectiveness of the present optimization methodology.

An approach of Proper Orthogonal Decomposition-aided Free-form Deformation with application in compressor blade design

“…the five new design variables as POD modes representing different shape deformation trend) via NSGA2 approach that is still often applied in many aerodynamic optimizations. [53][54][55] As is shown in algorithm1, x represents candidate, v represents guided possible marching step, r i , i = 1, 2, 3 represent random candidate in current generation; candidates, and constant F represents scaling factor in amplifying differential steps. After initializing the population of scale 25, each target vector of normalized candidate undergoes mutation and crossover operation before producing a testing sample.…”