摘要
直升机涡环状态严重影响飞行安全,其气流特性非常复杂,难以准确计算。本文在旋臂机设备上开展了涡环状态的专题实验,首先介绍了旋臂机的组成以及模型子系统、控制子系统和测试及数据采集子系统的工作特点。然后说明实验过程及实验数据处理方法。进行了不同总距、不同下滑角以及不同垂直速度的直升机下降实验,并测量其气流特性。最后以实验数据为基础,分析了在悬停状态、低速下降状态、涡环状态前期、中期及后期扭矩平均值和脉动幅度、拉力平均值和脉动幅度随下降速度的变化关系,确定了涡环状态的一般规律,探讨了涡环状态的改出方法。本文结果可为保证飞行安全提供参考。
Helicopter vortex-ring state influence flight safety badly, whose flow characteristic is very complex and hard to calculate accurately. This paper presents the experimental results of vortex-ring state performed on a Whirling Beam apparatus. First, the composition of Whirling Beam is introduced, and then the operation characteristics of model subsystem, the control subsystem, the measuring and data acquisition subsystem, the experiment procedure and data processing are introduced in turn. The helicopter descent experiments were performed at the different collective pitch, the different descent angle and the different vertical descent velocity. At last, based on the experiment data, the variation of mean torque value and fluctuation value, the mean thrust value and fluctuation value with descent velocity were analyzed under various flight conditions, such as hovering, low-speed descent, prior period, middle and last period of vortex-ring. The general rule of vortex-ring was determined, and the recovery method of vortex-ring was explored. These results can provide reference for flight safety guarantee.
出处
《实验力学》
CSCD
北大核心
2008年第4期371-376,共6页
Journal of Experimental Mechanics
关键词
直升机
实验
涡环状态
拉力
扭矩
helicopter
experiment
vortex-ring state
thrust
torque
