Schneck D J
Aviat Space Environ Med. 1980 Mar;51(3):256-64.
A mathematical theory is being developed in order to calculate the aerodynamic loading to which a pilot is exposed during high-speed ejections. Neglecting the initial effects of flow separation, results thus far indicate that a pilot's musculoskeletal system is not likely to withstand the tendency for limb-flailing if he is ejecting at Mach numbers in excess of about 0.7. This tendency depends very strongly upon the angle at which the pilot's limbs intercept a high-speed flow; the forces that cause limb dislodgement increase dramatically with speed of ejection. Examining the time-course of limb-dislodging forces after the initial onset of windblast, the theory further predicts the generation of a double vortex street pattern on the downstream side of the limbs of an ejection seat occupant. This results in the corresponding appearance of oscillating forces tending to cause lateral motion (vibration) of the limbs. The amplitude and frequency of these oscillating forces are also very dependent on the Mach number of ejection and the angle at which the pilot's limbs intercept the flow. However, even at moderate Mach numbers, the frequency can be as high as 100 cycles per second, and the amplitude rapidly exceeds a pilot's musculo-skeletal resistive powers for Mach numbers above 0.7.
为了计算飞行员在高速弹射过程中所承受的气动载荷，正在开发一种数学理论。忽略气流分离的初始影响，目前的结果表明，如果飞行员以超过约0.7马赫的速度弹射，其肌肉骨骼系统不太可能承受肢体挥舞的趋势。这种趋势在很大程度上取决于飞行员肢体拦截高速气流的角度；导致肢体脱位的力会随着弹射速度的增加而急剧增大。通过研究气流冲击初始发生后肢体脱位力随时间的变化过程，该理论进一步预测，在弹射座椅乘坐者肢体的下游侧会产生双涡街模式。这会导致相应的振荡力出现，这些振荡力往往会使肢体产生横向运动（振动）。这些振荡力的幅度和频率也非常依赖于弹射马赫数以及飞行员肢体拦截气流的角度。然而，即使在中等马赫数下，频率也可能高达每秒100次循环，并且对于马赫数高于0.7的情况，幅度会迅速超过飞行员肌肉骨骼的抵抗能力。
