Flow Field Analysis Of Helicopter Landing On Ship Based On Overset Grids

Ship-borne helicopters are favored by all countries in the world because of their flexible maneuverability and broad prospect.However,different from the relatively safe land,the flow field environment of the stern helicopter deck is complex and has many restrictive factors,which brings many difficulties for helicopter landing.Numerical simulation method is used in this paper to simulate and analyze the landing process of full-size ship-borne helicopter.In order to apply a more rational turbulence model in the simulation,helicopter/ship pool-wind tunnel test is carried out in the paper,in addition to further understanding the characteristics of the helicopter flow field,the turbulence model which is more closely related to the experimental results is found by combining the simulation work of the equal-scale numerical model,and applied to the flight dynamics simulation of ship-borne helicopter.The main contents of this paper are as follows:First,the helicopter/ship pool-wind tunnel test is carried out based on two-dimensional PIV technology,and the test results are collected and processed,the characteristics of helicopter flow field such as rotor blade tip vortex under different working conditions are observed,compared and analyzed.Then,Icem?Fluent and other commercial softwares are used to establish an equal-scale numerical model with reference to the experimental model,by using the overset mesh method,the standard k-? model and the standard k-? model are respectively used to simulate the numerical model.The results are compared with the experimental results qualitatively and quantitatively to obtain a better turbulence model for the simulation of complex flows.Secondly,a full-scaled numerical model is established with reference to the dimensional parameters of Z-9 ship-borne helicopter and 052 C destroyer,the numerical simulation of helicopter landing process is carried out based on the overset mesh method and the turbulence model determined above.The analysis of simulation results are divided into two stages: incline and vertical descents,the helicopter's flight dynamics characteristic curves in the ship landing process are extracted,and combined with the flow field characteristics such as equivalent vorticity graphs and velocity contours to analysis the interference on helicopter from rotor lift,longitudinal tensile and air force when the flow field of helicopter and ship varied from relatively independent to mutual coupling,in order to provide useful guidance for helicopter pilots.Finally,the work of this paper is summarized,and the future research work is expected.