Research On Calculation Method Of Aerodynamic Performance Of Coaxial Rigid Rotor

As a main aerodynamic component of the helicopter,the rotor has a great influence on the flight performance and noise level of the helicopter.Therefore,it is of great significance to carry out the flow field simulation and aerodynamic analysis for the rotor.Based on RANS equation,a numerical method for multi-rotor is developed to simulate flow field and predict aerodynamic performance of coaxial rigid rotor.The second chapter introduces the governing equations,spatial discretization,temporal discretization,turbulence model,boundary conditions and low-speed preconditioning method in CFD.The third chapter introduces the grid generation technology,unstructured overset grids technology and adaptive Cartesian grid technology in detail.In this paper,the nesting of unstructured grids and the self-adaptation of Cartesian grid are realized by means of host cell searching,numerical transfer algorithm and octagonal tree data structure,so as to prepare for the subsequent simulation of flow field of multi-rotor system with complex motion.In chapter four,according to the structural characteristics and differential control mode of the coaxial rigid rotor,a torque trim method is introduced which was then verified by rigid rotor XH-59 A.In chapter five,a numerical method coupled with overset grids technology and adaptive grid technology is established,and the experimental data of "Caradonna&Tung" rotor are used to verify that the method can effectively simulate the rotor flow field.The sixth chapter calculates the aerodynamic performance of XH-59 A in hover,including induced velocity,aerodynamic force and moment,hover efficiency,etc.,which is verified by test data,and the results show the accuracy and effectiveness of this paper's calculation method.