Numerical Simulation And Analysis Of Helicopter Rotor/Fuselage Flowfield Based On CFD Method

Based upon the momentum-source model, an N-S equation solution method for simulating the downwash flowfield of an isolated rotor has been developed. The method has been combined with a numerical solution approach for an isolated fuselage flowfield to form a new simulation method for the rotor/fuselage interaction flowfield. By the method, the influence analyses of design parameters on the rotor/fuselage interaction flowfield have been conducted. The major research work in the thesis is as follows:As the precondition and background of the research, the development of CFD methods in the simulation of helicopter rotor/fuselage flowfield is introduced briefly, and it is pointed out that the CFD method is important for the research of helicopter rotor/fuselage interaction flowfield.In Chapter 2, a hybrid mesh generation approach is given by considering the characteristics of helicopter rotor/fuselage flowfield and the requirements from the momentum-source method.In Chapter 3, in term of the blade motion, geometry and aerodynamic characteristics, an N-S equation solution method containing momentum-source term has been developed. By the method, the rotor downwash flowfield is simulated and analyzed. In order to validate the present method, the comparisons between the present computation results with available experimental date have been made.From an unstructured mesh generation approach for isolated fuselages, an N-S equation simulation method is used to calculate the fuselage flowfield in Chapter 4. The ROBIN fuselage is taken as numerical examples, and the flowfield around it is simulated. Then, the computed results are compared with available experimental data and a few conclusions are obtained.Based upon the above mesh generation approach and numerical simulation approach, an N-S equation solution method used to simulate the rotor/fuselage interaction flowfield is developed in Chapter 5. By this method, the calculations for the flowfield of a rotor, a fuselage and a combined rotor/fuselage have been conducted and the calculated results have been analyzed.In Chapter 6, the simulations have been done on the rotor/fuselage interactional flowfield with the variation of design parameters. Some meaningful results are obtained by analyzing the influence of the separation between rotor and fuselage as well as the rotor radius on the interactional flowfield.