Research On The Aerodynamic Coupling Of Large Ship And Multi Aircraft Lifting And Lowering

The research of helicopter / ship coupled flow field is an important topic in the field of helicopter,but the current research work focuses on the research of single aircraft and destroyer type.With the service of amphibious attack ships in China,the research of multi aircraft / ship coupled flow field on large ships has become more and more urgent.Therefore,this paper has carried out the research of aircraft / ship and multi aircraft / ship coupling flow field based on momentum source method,analyzed the flow characteristics of coupling flow field and the force of helicopter rotor under various working conditions;on the other hand,based on the one-way coupling helicopter balancing calculation method,a two-way coupling helicopter balancing calculation method with CFD has been established and applied to the generation of helicopter theoretical wind limit diagram.The main research work is as follows:In the first chapter,the background of this paper and the current situation of the research on the multi aircraft take-off interference and helicopter take-off and landing wind limit map of aircraft /ship and large-scale ship at home and abroad are described.It is pointed out that the existing helicopter / ship coupled CFD calculation focuses on single machine / single ship mode,which can not meet the needs of aviation operations on amphibious attack ships in the future in China;at the same time,the generation of theoretical wind limit diagram is mainly based on one-way coupling method,without considering the rotor interference on the flow field.The research direction of this paper is proposed: the calculation and analysis of multi aircraft take-off and landing flow field,the establishment of two-way coupling helicopter trim calculation model for the generation of theoretical wind limit diagram.In Chapter 2,the numerical simulation method of isolated ship based on RANS and hybrid Les /RANS model is established,and the numerical simulation analysis method of helicopter / ship coupled flow field is established by adding momentum source model on the basis of RANS method.The simulation results of isolated LHA ship model and isolated rotor are compared with the experimental data,which verify that the established flow field calculation and analysis method can be used for the research of helicopter / ship coupled flow field.In the third chapter,the flow field of isolated ship and the coupled flow field of aircraft / ship are studied respectively.The Reynolds averaged N-S equation,the mixed Les / RANS method and the momentum source method are used to calculate the relevant examples.The characteristics of the flow field of isolated ship and aircraft / ship coupling are analyzed in detail,and the flow field of isolated ship using the mixed Les / RANS method is monitored.It lays a foundation for the further research on the coupled flow field of multi engine / ship.In view of the characteristics of large-scale amphibious attack ship,such as wide deck,many aircraft take-off and landing points,and the deck flow field of each part changes greatly.In the fourth chapter,the coupling flow field between multiple aircrafts on the fore deck and the aft deck of a ship is studied by using the momentum source method.The wind direction,the distance between the rotor and the deck and the transverse moving distance of the rotor influence the flow field characteristics of the deck,the spectrum characteristics of the rotor tension and the variation of the rotor control amount are mainly studied.It provides a theoretical basis for the safe take-off and landing of multiple aircrafts on large ships.In the fifth chapter,based on the momentum source CFD calculation,the traditional one-way coupling helicopter balancing calculation method is changed into two-way coupling balancing calculation model.Combined with the domestic and foreign restrictions on flight safety,the coupling balancing calculation model is used to generate the wind limit diagram of helicopter landing,which provides a reference for the safe take-off and landing of carrier helicopter.The sixth chapter summarizes the research work of this paper,puts forward the innovation of the research,and expounds the shortcomings of this research and the direction of future research.