Numerical Simulation Of Rotor Flowfields And Aeroelasticity

Numerical simulation of rotor field is one of the important and difficult issues in helicopteraerodynamics. Based on the dynamic overset structure grids and the solving of the Euler/N-Sequations, a numerical method has been developed to simulate the flow field of the rotor, and thecorresponding computational software is developed. Then, coupling with blade structural dynamicmodel, a CFD/CSD coupling method is developed for rotor aeroelastic. The primary works in thispaper are presented as follows.1. Based on the existing flowfield solver, the dynamic overset structure grids method isinvestigated. The method include digging algorithm, the optimization methods of hole boundary usingthe distence to wall, the ADtree method for searching donor cell, and the trilinear interpolation forexchanging the data between the grids. Some cases have also been done to validate the method.2. The method is applied to simulate the flow filed of a drag-type vertical axis wind turbine.Under the considering the two cases: blade with cut slots and blade without cut slots, two modelswere established for calculating the system’s output power with respective to the different rotate speedconditions. The results show that with cut slots the output power is higher than that without cut slots.And the sumilation of three dimensional models is done later, the results are compared with the windtunnel data.3. The numerical simulation of the helicopter rotor is done using the developed method. Thehover and forward flight flow field are calculated, the good agreement between the hover results andthe wind tunnel data again indicate the reliability of the developed method. Two helicopterrotor-fuselage models, which are the GT model and Robin body-rotor model, are simulated to studythe blade tip vortex, wave, and the rotro-fuselage interaction, and some meaningful results areobtained.4. The blade aeroelastic respone model is established based on classical aerodynamic model, theaerodynamic data of CFD is used to correct the classical aerodynamic data,and then a CFD/CSDloose coupling method is developed for rotor aeroelastic. In the loose coupling method, airloads datafrom the CFD solver and blade motion from the CSD solver are exchanged on per revolution or onceper blade passage, periodic. A case has been done successfully and analysed.