摘要
综述关于飞行器空气动力学动态性能的实验研究中所面临的问题，困难和有关的实验技术进展状况。
The main feature o the unsteady flow over the airfoils and delta wings are discussed.Large hysteresis loop of the aerodynamic coefficients might appear over delta wing and airfoils undergoing large amplitude and high frequency vibration.Large variation of the free steam velocity might cause very large changes of the aerodynamic force coefficients. The facilities for experiments of unsteady aerodynamics include the wind tunnel and water channel that could produce certain unsteady flows;the aerodynamic balance and dynamic pressure transducers;the flow visualization facilities.The unsteady flow of designed velocity variation curve might be generated by special device,such as piston driven water tunnel.The problems for generating designed unsteady velocity variations in the common wind tunnel and water channels are discussed.The generating of good decelerating flow is especially difficult.It is mainly due to the serious separation flows generally occurs in decelerating flow.The elastic displacement and rotation of the model relative to the support would change the relative flow to the model.They might cause difficulties to the force measurement and problems in processing data.Large elastic vibration of the model relative to oncoming flow also makes the relative flow deviated from the designed.This might cause the aerodynamic force deviated far from that without model vibration.The difficulties of simultaneous flow visualization and force measurement are mentioned briefly.
出处
《流体力学实验与测量》
CSCD
1998年第1期1-7,共7页
Experiments and Measurements in Fluid Mechanics
基金
自然科学和气动预研基金
关键词
空气动力学
非定常流
机翼
动态实验技术
aerodynamics
unsteady flow
wing
dynamic stall
experimental techniques
