论文部分内容阅读
许多证据表明,昆虫飞行的机理与飞机及直升机的机理大不相同。zanker&Gotz测出了被系住的果蝇所产生的瞬时力。并发现这些力不能用常规空气动力学理论来解释。这些力也是这些果蝇使用不一般的方法来产生升力的证据。 在飞机稳态飞行时,空气在机翼上方流动比下方快。这时绕机翼周围有一纯环流。正是具有附体环流的机翼在空气中的运动产生了升力。可是,如果机翼从静止开始加速,那么它必须移动比它本身宽度长几倍的距离,才会有环流绕流机翼而产生足够的升力以使飞机达到稳态飞行。这一现象叫做Wagner效应。
There is much evidence that the mechanism by which insects fly is quite different from that of aircraft and helicopters. Zanker & Gotz measured the instantaneous force generated by the tethered fruit fly. And found that these forces can not be used to explain the conventional aerodynamics. These forces are also evidence that these flies use unusual ways to generate lift. At steady-state flight, the air flows faster than below under the wing. Around this time around the wing there is a pure circulation. It is the movement of the airfoil with an appendage circulation that produces lift. However, if the wing accelerates from rest, it must move a few times longer than its own width before it circulates around the wing to generate sufficient lift to allow the aircraft to reach steady-state flight. This phenomenon is called the Wagner effect.