报告题目：Analysis of Start-up and Shutdown of Rotor in Complex Wind Conditions on Sea-based Oil Rig
报告人： Prof. Jianhua Zhang (The Pennsylvania State University)
报告时间：2019年6月19日（周三）上午10:00
报告地点：明故宫校区5号楼201报告厅
主办单位：直升机旋翼动力学国家级重点实验室、航空学院
报告内容简介：
A combined rotor transient responses and analysis tools/computational fluid dynamics effort was completed to assess the rotor response in a complex flowfield. A generic helicopter on a oil-rig platform was chosen because the bluff nature of the rig presents unique challenges to rotorcraft operations. The rotor start-up and shutdown simulation model was validated with the test data. Comprehensive studies of rotor transient responses under various wind directions and wind speeds were conducted to establish the safe-operation envelope. The study found that horizontal wind velocities may be accelerated by the oil-rig building corner, and cause significant rotor flap motions. The upwash and downwash flow due to the blockage of the helicopter fuselage to the crosswind had great impact on rotor transient responses, and the peak blade flap responses can be 2.5 times higher than the simulation results when the effect of airframe on air wake was ignored. The influence of unsteady air wake on rotor transient responses was also investigated, and the results showed that it could increase the blade tip deflections by 70% if the unsteady-flow components were included. The sensitivity of the rotor-blade initial azimuth positions for rotor start-up operations was also examined.
报告人简介：
Jianhua Zhang currently is a research faculty at Rotorcraft Center, Department of Aerospace Engineering at Pennsylvania State University. He received B.E. and M.E. in Aeronautical Engineering in 1987 and 1990 from NUAA. Between 1990 and 1966, he was an aeronautical engineer at China Helicopter Corp. of AVIC. He graduated from Penn State University in 2001 with Ph.D.in Aerospace Engineering. He has more than fifteen years of extensive experience on Rotorcraft Dynamics, Aerodynamics and Aeromechanics, and has been working on many rotorcraft related projects with NASA, Army Research Lab, ONR, and rotorcraft industries. He has won NASA Group Achievement Award for his work on composite rotor blade design and analysis in NASA Heavy Lift Rotorcraft Systems Investigation in 2007.
