On Low Altitude Flight through the Atmospheric Boundary Layer
On Low Altitude Flight through the Atmospheric Boundary Layer
复制标题
低空飞行穿越大气边界层
DOI：
10.1260/1756-8293.2.2.55
复制
发表时间：
2010
影响因子：
1.4
通讯作者：
M. Abdulrahim
中科院分区：
文献类型：
--
作者：
Simon C Watkins;M. Thompson;B. Loxton;M. Abdulrahim
低速微飞行的主要挑战是大气边界层（ABL）产生的瞬态和时间平均速度，特别是离地面几米的湍流。本文回顾了来自气象学家和风力工程师的现有数据，并简要描述了mav经历的空间和时间速度场的测量。分析了来自各种地形的数据，其中大部分数据是在相对混合良好的湍流（即远离建筑物等局部影响）和名义上的中性稳定条件下获得的。去除局部效应的数据的光谱表现出预期的5/3 Kolmogorov定律。为了了解MAVs可能的滚转和俯仰输入，研究了瞬时流动俯仰角（从四个小型横向位移探头获得）。值得注意的是，对于获得的所有数据，横向分离的变化下降相对缓慢，分离减少到最接近的探针间距14mm。这一效应被认为可以解释，当存在任何可察觉的大气风时，在保持良好的滚转控制以减小飞行器的尺度时，驾驶员所经历的日益增加的困难。
Major challenges to low speed micro flight are the transient and time-averaged velocities arising from the Atmospheric Boundary Layer (ABL), particularly turbulence a few metres above the ground. In this paper, existing data from meteorologists and wind engineers are reviewed and measurements dedicated to understanding the spatial and temporal velocity fields that MAVs experience are briefly described. Data from a wide variety of terrains are analysed, with the majority of data obtained in relatively well mixed turbulent flow (i.e. away from local effects such as buildings) and for conditions of nominally neutral stability. Spectra for data well removed from local effects exhibited the expected 5/3rds Kolmogorov law. Transient flow pitch angles were investigated (obtained from four small laterally displaced probes), in order to understand the possible roll and pitch inputs to MAVs. It was noted that for all data obtained the variation with lateral separation decreased relatively slowly with reducing separation down to the closest inter-probe spacing of 14mm. This effect is thought to explain the increasing piloting difficulties experienced in maintaining good roll control for decreasing scales of craft when any appreciable atmospheric winds are present.