Research Of A Novel Airframe/Inlet Integrated Full-waverider Aerodynamic Design Methodology For Air-breathing Hypersonic Vehicles

This research concentrates on the aerodynamic design methodology for air-breathing hypersonic vehicles.Using a combination of theoretical analysis,numerical simulations and experimental measurements,a novel airframe-inlet integrated full-waverider aerodynamic design methodology for air-breathing hypersonic vehicles is studied by use of both the method of characteristics and the streamline tracing technique.And then this design concept is achieved on basis of the axisymmetric basic flow model: not only the waverider design for the lower surfaces of the forebody,engine cowl and wings can be achieved,but also the airframe and streamline tracing inlet can be integrated well,under the condition that the waverider characteristics of the entire vehicle is not destroyed;in on-design state,the entire vehicle can ride on the bow shock wave;specifically,the forebody is designed as the waverider,named the forebody waverider,and it behaves as the pre-compression surface to efficiently provide the inlet system with the required compression flow field;the lower surfaces of the engine cowl and wings are also designed as the waverider,named the afterbody waverider,in order to take advantage of the waverider's high lift-to-drag ratio characteristics.Both the waverider design methodologies and waverider applications in the airframe-inlet integration methodology for the air-breathing hypersonic vehicles by the domestic and overseas scholars are reviewed and classified systematically,and the future research and development trends are also analyzed.In order to investigate the accuracy of the numerical methods employed in the research on hypersonic vehicle and inlet,three experimental models are chosen to discuss the code validation and precision quantitative evaluation.The “validation metric” method in statistics is introduced,and the level of agreement between the computational results and available experimental data are quantitatively evaluated.Especially,the “validation metric” method is applied to the grid independence verification,precision analysis,and impact assessment of different turbulence models on the numerical simulations for the hypersonic inlet.The research on the design methods of generic waverider generated from axisymmetric supersonic flows is carried out.First,four unit processes for the method of characteristics,namely,the interior point,direct wall point,indirect wall point and external shock wave point,are discussed in detail.Second,the axisymmetric flow model and its design method utilizing the method of characteristics are discussed.Then,both the streamline tracing technique that is based on left-running Mach lines and the generic waverider design method are also presented.Third,a pointed von Karman ogive is applied to design the novel von Karman waverider proposed in this thesis.Then,the numerical methods are employed to validate the applicability of this novel design concept to an aerodynamic configuration.A comparison model is designed using the conventional design concept and its performance is numerically predicted to analyze the differences between the novel and conventional design concepts.Finally,the influences of the surface pressure distribution of a basic flow field on the shapes and performances of waveriders are investigated.With the aim of integrating a ramjet or scramjet with an airframe,a novel airframe-inlet integration methodology for the hypersonic waverider vehicle is proposed,and this kind of vehicle is named “airframe-inlet integrated full-waverider”,or “full-waverider” for short.First,the design principle,design procedure,and basic flow model for the full-waverider based on a pointed body of revolution are described in detail.Second,the airframe-inlet integrated axisymmetric basic flow model that accounts for both external and internal flows is designed based on a pointed body of revolution.Subsequently,its design idea,procedure and method are described in detail.Finally,the design methodologies of both the integrated axisymmetric basic flow model and the full-waverider vehicle are verified by numerical simulation.At the same time,the aerodynamic characteristics and performances of both the integrated axisymmetric basic flow model and the full-waverider vehicle are analyzed under the design condition using the numerical computation.With the aim of extending design freedom for the airframe-inlet integrated axisymmetric basic flow model,the basic flow model based on the axisymmetric shock wave is proposed,and then the design methodology for the full-waverider is extended based on the axisymmetric shock wave flow model.First,the design principle,design procedure,and basic flow model for the full-waverider based on the axisymmetric shock wave flow model are described in detail.Second,the airframe-inlet integrated axisymmetric basic flow model that accounts for both external and internal flows is designed based on the axisymmetric shock wave flow model.Subsequently,its design idea,procedure and method are described in detail.Then,the design methodologies of both the integrated axisymmetric basic flow model and the full-waverider vehicle based on the axisymmetric basic shock wave are verified by a computational numerical method.At the same time,the aerodynamic characteristics and performances of both the integrated axisymmetric basic flow model and the full-waverider vehicle are analyzed under the design condition using the numerical computation.Meanwhile,the design for the aerodynamic configuration of the full-waverider vehicle is preliminarily studied,and the weight and range are also evaluated.Finally,a comparison model is designed using the conventional design concept and its performance is numerically predicted to analyze the differences between the new and conventional design concepts.At the same time,the effects of both the design parameters of the basic flow model and the trailing-edge curve on the shapes and performances of full-waverider vehicles are investigated.The evaluation method for the boundary-layer displacement thickness based on the momentum integral equation is described.Two schemes for the boundary-layer viscous correction of the forebody-inlet are investigated.Subsequently,the effects of the two viscous correction schemes on the performances of the forebody-inlet are compared and analyzed by the numerical computation.Moreover,the boundary-layer viscous correction methods are verified.Wind tunnel experiments are carried out to test the aerodynamic characteristics of the simplified configuration for the full-waverider vehicle.Experimental data,numerical simulation and theoretical results are in good agreement,and it further indicates that the proposed full-waverider design theory is reasonable and the corresponding design methodology is effective.At the same time,the effectiveness of the boundary-layer viscous correction method for the forebody-inlet is further proved.