WAKE GEOMETRY CALCULATIONS FOR TILT-ROTOR USING VISCOUS VORTEX METHOD  

作　　者：魏鹏 史勇杰 徐国华 

机构地区：[1]Science and Technology on Rotorcraft Aeromechanics Laboratory,Nanjing University of Aeronautics and Astronautics

出　　处：《Transactions of Nanjing University of Aeronautics and Astronautics》2013年第4期297-305,共9页南京航空航天大学学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(11302103)

摘　　要：A tilt-rotor unsteady flow analytical method has been developed based upon viscous vortex-particle method.In this method,the vorticity field is divided into small assembled vortex particles.Vortex motion and diffusion are obtained by solving the velocity-vorticity-formed incompressible Navier-Stokes equations using agrid-free Lagrangian simulation method.Generation of the newly vortex particles is calculated by using the Weissinger-L lifting surface model.Furthermore,in order to significantly improve computational efficiency,a fast multiple method(FMM)is introduced into the calculation of induced velocity and its gradient.Finally,the joint vertical experimental(JVX)tilt-rotor is taken as numerical examples to analyze.The wake geometry and downwash are investigated for both hover and airplane modes.The proposed method for tilt-rotor flow analysis is verified by comparing its results with those available measured data.Comparison indicates that the current method can accurately capture the complicated tilt-rotor wake variation and be suitable for aerodynamic interaction simulation in complex environments.Additionally,the aerodynamic interactional characteristics of dual-rotor wake are discussed in different rotor distance.Results show that there are significant differences on interactional characteristics between hover mode and airplane mode.A tilt-rotor unsteady flow analytical method has been developed based upon viscous vortex-particle meth- od. In this method, the vorticity field is divided into small assembled vortex particles. Vortex motion and diffusion are obtained by solving the velocity-vorticity-formed incompressible Navier-Stokes equations using a grid-free La- grangian simulation method. Generation of the newly vortex particles is calculated by using the Weissinger-L lifting surface model. Furthermore, in order to significantly improve computational efficiency, a fast multiple method （FMM） is introduced into the calculation of induced velocity and its gradient. Finally, the joint vertical experimen- tal （JVX） tilt-rotor is taken as numerical examples to analyze. The wake geometry and downwash are investigated for both hover and airplane modes. The proposed method for tilt-rotor flow analysis is verified by comparing its re- sults with those available measured data. Comparison indicates that the current method can accurately capture the complicated tilt-rotor wake variation and be suitable for aerodynamic interaction simulation in complex environ- ments. Additionally, the aerodynamic interactional characteristics of dual-rotor wake are discussed in different ro- tor distance. Results show that there are significant differences on interactional characteristics between hover mode and airplane mode.

关 键 词：tilt-rotor rotor wake viscous vortex method aerodynamic interaction 

分 类 号：V2[航空宇航科学技术]