Parameterization And Optimization Design For Forebody And Inlet Of Hypersonic Vehicle

Aerodynamic configuration design has experienced a journey from cut-and-try design to reverse design and further to optimization design.Based on powerful computing,credible optimization algorithm and flexible modeling function,optimization design,which refers to a multidisciplinary combination,provides a possible way to optimize complex shape.In this paper,parameterization and optimization for forebody/inlet of hypersonic vehicle was systematically and deeply investigated with combining modeling function,CFD and optimization algorithm.For modeling function,the corresponding function was developed to describe the shape of forebody and internal passage according to their two characteristic,respectively.The developed function can generate much more flexible modeling by using fewer control variables.For searching optimal solution,a optimization platform,which integrated modeling,grid generation,CFD and algorithm,was set up and could optimize different cases.The purpose of algorithm is to discard worse individuals and choose better solutions and finally get the best optimal set.What's more,this paper also conducted relevant analysis about aerodynamic performance and flow field characteristic.In terms of designing forebody,a method was developed to parameterize forebody coupling the inlet profile.The method can completely parameterize forebody/inlet by five variables.And it can maintain the characteristic of inlet profile on lower compression surface.Based on the optimization platform,the forebody coupling inlet profile was finally optimized the optimal solutions of two objectives,drag and volume fraction,was searched through generic algorithm.Then the three types of configurations among the optimal solutions(Pareto)were chosen to study and analyze aerodynamic performance and flow field characteristic.In terms of designing isolator,a method,which can parameterize isolator based on shape blending function,was developed to design variable cross-section curved isolator according shape constraint and space constraint.The basic idea is to decouple shape-transition design and offset control line design.When the two parts designs were completed,the transition shapes were assembled to offset control line.Compared with the original configuration,rectangular-to-circular curved isolator and novel-to-circular isolator were parameterized and optimized,respectively.Meanwhile,the total pressure recovery,withstanding backpressure and flow field was analyzed.In order to fast design isolator,shape-transition curved isolator design method with controllable cross-sectional area,the other designing method of isolator,was also developed.Cross-sectional area constraint was introduced in the optimizing process because the cross-sectional area of traced passage is uncontrollable when implementing streamline tracing technique to design curved duct.The result shows that the second method can search optimal solution with controllable cross-sectional area.Similarly,the second method also was applied to rectangular entrance and novel entrance curved isolators.