Research On Wing In Ground Effect Craft Assisted Reusable Launch Vehicle Takeoff Technology

Horizontal takeoff and landing(HOTOL)is one of the important developing directions of Reusable Launch Vehicle(RLV).Landing gear design has become a difficulty of HOTOL of RLV due to the big difference between its takeoff weight and landing weight.Ground assisted takeoff(GATO)can replace the taxiing of RLV in order to reduce the design requirement of the landing gear design,which makes GATO become one of the key technologies of HOTOL of RLV.In this paper,the Wing in ground(WIG)effect craft assisted takeoff is chosen as the GATO of RLV,and the research on related technology is conducted.First of all,the overall parameters and technical requirements are chosen as the design requirements of WIG craft.The combination of conceptual design method of regular aircraft and seaplane is used to finish the conceptual design of WIG craft.The 3-D model of WIG craft is built by CATIA.The aerodynamic analysis model of WIG craft of the cruise state is built based on the finite volume method for solving Navier-Stokes equations.The aerodynamic characteristics of the model are analyzed by Fluent so as to choose the optimum wing incidence angle and flight height of WIG craft of the cruise state.Later,the aerodynamic characteristics of the cruise state of WIG craft piggybacking RLV are analyzed so as to choose the optimum angle of attack of RLV of the piggyback cruise state.The design and kinematics simulation of the fixation and separation mechanism between two crafts and the separation process is conducted.The aerodynamic characteristics of the piggyback separation state are analyzed to draw the safe separation boundary pattern related to the combination of angle of attack of two crafts.The unsteady aerodynamic characteristics of the after-separation state are analyzed based on the dynamic mesh technology.The result of the analysis is compared with the noninterference situation in order to obtain the interference between two crafts.In this paper,a quite heavy WIG craft is designed,the aerodynamic characteristics of the piggyback cruise and separation state are analyzed,and the unsteady aerodynamic characteristics of the after-separation state are analyzed.All of them have certain innovation and provide technical reference for the related technology research in the future.