Aerodynamic Forces Acting on an Albatross Flying Above Sea-Waves
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摘要: 针对信天翁近海面的飞行条件，研究信天翁能在大风浪中高效飞行的力学机理．将信天翁简化为二维机翼，采用势流理论的面元方法，重点研究了波浪的有益干扰．给出了信天翁在匀速固定高度飞行和自由飞行两种状态下的波浪扰动力．计算结果表明：信天翁的飞行效率不仅取决于飞行的高度和速度，而且取决于浪高和波长；在大风浪下信天翁可以从波浪有益干扰中获得推力来抵消部分飞行阻力，提高飞行效能．Abstract: Numerical investigation on the dynamic mechanism has been made for an albatross to fly effectively in the region near sea surface.Emphasizing on the effect of the sea wave,the albatross is simplified as a two-dimensional airfoil and the panel method based on the potential flow theory is employed to calculate the wave effect on the aerodynamic forces.The numerical results have been presented for the states of:1)flying at different constant speeds with constant heights above sea level; 2)flying at different constant speeds with the combined oscillations of pitching and free heaving.The study on the cases shows that the albatross.flight efficiency depends on not only the speed and height of flight but also the wave amplitude and the wavelength.The albatross benefits by wave effect to get thrust,so as to reduce the resistance in the circumstances of rough sea.
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Key words:
- unsteady /
- aerodynamics /
- panel method /
- wave effect /
- albatross
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