The dynamics of parabolic flight: flight characteristics and passenger percepts.
The dynamics of parabolic flight: flight characteristics and passenger percepts.
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DOI：
10.1016/j.actaastro.2008.04.009
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发表时间：
2008-09
影响因子：
3.5
通讯作者：
Shelhamer, Mark
中科院分区：
文献类型：
--
作者：
Karmali, Faisal;Shelhamer, Mark
在飞行器中飞行抛物线轨迹是在地球上创造自由落体的少数方法之一，这对宇航员训练和科学研究很重要。在这里，我们回顾了抛物线飞行的物理基础，解释了由此产生的飞行动力学，并描述了几个违反直觉的发现，我们用实验数据证实。通常情况下，飞机飞行抛物线弧，产生约25秒的自由落体（0 g），然后是40秒的增强力（1.8 g），重复30-60次。虽然乘客认为重力为零，但实际上加速度而不是重力发生了变化，因此我们要注意“微重力”和“零重力”这两个术语。“尽管飞机轨迹包括大（45°）的上仰和下仰姿态，乘客仍会感受到垂直于飞机地板的净力。这是因为飞机产生适当的升力和推力，分别产生所需的垂直和纵向加速度，尽管我们在这些轨迹的某些部分测量到中等（0.2 g）的后向加速度。飞机俯仰旋转（平均3°/s）几乎不能被前庭系统检测到，但可能会影响一些物理实验。研究人员在计划、分析和解释抛物线飞行实验时应考虑这些细节。
Flying a parabolic trajectory in an aircraft is one of the few ways to create freefall on Earth, which is important for astronaut training and scientific research. Here we review the physics underlying parabolic flight, explain the resulting flight dynamics, and describe several counterintuitive findings, which we corroborate using experimental data. Typically, the aircraft flies parabolic arcs that produce approximately 25 seconds of freefall (0 g) followed by 40 seconds of enhanced force (1.8 g), repeated 30–60 times. Although passengers perceive gravity to be zero, in actuality acceleration, and not gravity, has changed, and thus we caution against the terms "microgravity" and "zero gravity. " Despite the aircraft trajectory including large (45°) pitch-up and pitch-down attitudes, the occupants experience a net force perpendicular to the floor of the aircraft. This is because the aircraft generates appropriate lift and thrust to produce the desired vertical and longitudinal accelerations, respectively, although we measured moderate (0.2 g) aft-ward accelerations during certain parts of these trajectories. Aircraft pitch rotation (average 3°/s) is barely detectable by the vestibular system, but could influence some physics experiments. Investigators should consider such details in the planning, analysis, and interpretation of parabolic-flight experiments.
影响因子：
3
作者：
Vaitl, D;Mittelstaedt, H;Baisch, F
通讯作者：
Baisch, F
影响因子：
5.5
作者：
JONES, GM;MILSUM, JH
通讯作者：
MILSUM, JH