aerodynamic balance

The fastest human-powered vehicles at sea levels are recumbent bicycles enclosed in streamlined aerodynamic shells. These vehicles have an upper speed limit near 40 m/ s-the speed at which the human can just barely produce enough thrust to balance the drag force from the air.

目前最快的人力车是包裹在流线型空气动力学外壳里的躺式自行车，这种自行车的速度最快能达到将近每秒40米，再快人力就已经不足以抗衡空气阻力了。

The base principal in controlling method is madding aerodynamic force acting an transmission line changed into approximate balance state.

此方法的基本原理是：使作用在输电线上的气动力近似地成为平衡力系，从而控制输电线舞动。

The accomplishing method is that the attack angles of aerodynamic forces are made changing along transmission line so aerodynamic forces are made being approximate balance state by spiral winding plastic belt on transmission line.

实现的方法是在输电线螺旋地缠绕横截面为三角形的塑料带，使气动力的攻角沿输电线的长度方向周期性地变化，使作用在输电线上的气动力近似地成为平衡力系。

To obtain good aerodynamic characteristics, the radial aerodynamic balance equations were adopted to build the fan's rotating blades, which were evolved from the simplified three dimensional flow theories, the constraint conditions and the control vortex theory.

采用简化的三元流动设计理论得到叶轮叶片气动设计径向平衡方程式和求解约束条件，进而引入了控制涡设计理论进行风扇叶片造型，获得了优良的气动性能；