The Optimization Design Of Afterbody Nozzle For Airbreathing Hypersonic Vehicles

The aims of this thesis are studying the optimization problem of two dimensional Singel Expansion Ramp Nozzle for propulsion/airframe integrated airbreathing hyepersonic vehicles.The multi-objective evoltionary algorithm NSGA-II that uses nondominated sorting and sharing strategy is achieved.Then the multi-objective optimization performance of this algorithm is validated according to tests of typical multi-objective optimization problems.The optimization process is designed by combining with multi-objective optimization algorithm ,2-D automated grid-generation programme and PNS flow field solver .It is verified that the algorithm has the ability to deal with the multi-objective optimization problem of 2-D SERN,and its performance is better than some commercial software.Then,twelve different design models divided into four kinds are obtained,and the design multi-objective optimization problem of these models are studied at last.Investigative results indicate that performances of all optimization schemes obtained in this thesis are better than existent optimization result under PNS solver condition;further more,the optimization thrust of one design model increases nearly 6%.It is validated that all design models obtained in this thesis are imaginative schemes and the algorithm can be used into some related optimization design problems of airbreathing vehicles.