Research On The Unsteady Aerodynamic Interaction Between Rotor／fuselage

Aerodynamic interaction between the rotor and fuselage of a helicopter is the most complex aerodynamic problem being three-dimensional and unsteady, also is one of the important technology of helicopter designing. Based on the method of the CFD, a technique of unstructured dynamic patched grid is developed to solve unsteady flow that contains rotational boundary. Unsteady aerodynamic problem of rotor / fuselage interference is calculated by using this method. Due to the character of rotational boundary, the whole computational domain is divided into rotational area and static area. The rotational area and static area are generated separately by corresponded grid. Information of the two districts transmits through the patched interface. At the calculation of each unsteady time step that forms a complete set of computational grid.The article introduced the research background and development overview of the helicopter aerodynamic interaction firstly. Then the control equations of the unsteady aerodynamic problem are established, also including the discretization of the space and time. In order to verify the efficiency of method, the isolated fuselage and isolated rotor are simulated. Also, the rotor / fuselage aerodynamic interaction of the"Georgia Tech"are simulated, and the unsteady pressure coefficient of different points that above the fuselage is calculated. The results are compared with the experimental data.Lastly, a separate body and rotor / fuselage unsteady aerodynamic interaction in hovering and forward flight of a model helicopter are calculated, also the results are analyzed and some meaningful results are got.