Non-Steady-State Aerodynamics of the Flight of Encarsia Formosa
Non-Steady-State Aerodynamics of the Flight of Encarsia Formosa
复制标题
福尔摩沙小恩卡虫飞行的非稳态空气动力学
DOI：
--
复制
发表时间：
1975
期刊：
影响因子：
--
通讯作者：
C. Ellington
中科院分区：
文献类型：
--
作者：
C. Ellington
Weis-Fogh（1973）证明了某些昆虫飞行所需的高升力系数与稳态空气动力学不相容，并提出了两种新的机制，即投掷和翻转，即翅膀运动在翅膀周围产生循环之前，独立于平移。用另一种方法重新估计最小稳态升力系数，并包括一些可能的改进，对这个前提进行了研究。用这种方法得到的稳态升力系数对于相应的雷诺数来说仍然太高。平均发行量约为3份。然而，在飞动和翻转过程中，每只翅膀周围可能产生8 cm2s−1，这个值大于平动过程中满足库塔-朱可夫斯基条件的环流。后缘涡与停止涡具有相同的意义，应该随着机翼的平移而脱落。粗略计算表明，在每个半冲程中，束缚涡度的相应减少足够小，足以使机翼周围保持足以飞行的平均循环。
Weis-Fogh (1973) demonstrated that the high lift coefficients necessary for flight in certain insects are incompatible with steady-state aerodynamics and proposed two novel mechanisms, the fling and the flip, whereby the wing movements generate circulation around the wings prior to and independently of translation. This premise is investigated for the flight of the small chalcid wasp Encarsia formosa by re-estimating the minimum steady-state lift coefficient by another method and including some possible refinements. The steady-state lift coefficient obtained in this manner is still too high for the relevant Reynolds number. An average circulation of about 3. 8 cm2s−1 may be created around each wing in the fling and flip, however, and this value is higher than the circulation during translation which satisfies the Kutta-Zhukovski condition. Trailing edge vortices, with the same sense as stopping vortices, should then be shed as the wings translate. A rough calculation shows that the corresponding decrease in bound vorticity during each halfstroke is small enough to allow an average circulation remaining around the wings sufficient for flight.