Norberg U M, Kunz T H, Steffensen J F, Winter Y, von Helversen O
Department of Zoology, Zoomorphology, University of Gothenburg, Sweden.
J Exp Biol. 1993 Sep;182:207-27. doi: 10.1242/jeb.182.1.207.
Energy expenditure during flight in animals can best be understood and quantified when both theoretical and empirical approaches are used concurrently. This paper examines one of four methods that we have used to estimate the cost of flight in a neotropical nectar-feeding bat Glossophaga soricina (Phyllostomidae), namely the use of kinematic and morphological data and aerodynamic theory to estimate the mechanical power requirements (power output) for hovering and horizontal forward flight. A hot-wire anemometer was used to measure induced velocity (the velocity of air accelerated by the wings) during hovering in order to estimate induced power. Our estimate of aerodynamic power (the sum of induced, profile and parasite powers) required for a 0.0105 kg G. soricina to hover is 0.15 W and our estimate of the inertial power (the power required to oscillate the wings) is 0.19 W. Thus, the total mechanical power for hovering is 0.34 W or 32.4 W kg-1. The mechanical power required for horizontal forward flight, near the minimum power flight speed (4.2 ms-1) for a 0.0117 kg bat is 0.14 W (12.3 W kg-1), of which 0.10 W is aerodynamic power and 0.042 W is inertial power. Comparison with our results on metabolic power requirements estimated from nectar intake gives a mechanical efficiency of 0.15 for hovering flight and 0.11 for forward flight near the minimum power speed.
当同时使用理论方法和实证方法时，动物飞行过程中的能量消耗才能得到最好的理解和量化。本文研究了我们用于估算新热带地区食蜜蝙蝠苏氏长舌蝠（叶口蝠科）飞行成本的四种方法之一，即利用运动学和形态学数据以及空气动力学理论来估算悬停和水平向前飞行所需的机械功率（功率输出）。使用热线风速仪测量悬停过程中的诱导速度（翅膀加速空气的速度），以估算诱导功率。我们估算一只体重0.0105千克的苏氏长舌蝠悬停所需的空气动力学功率（诱导功率、剖面功率和寄生功率之和）为0.15瓦，估算的惯性功率（摆动翅膀所需的功率）为0.19瓦。因此，悬停的总机械功率为0.34瓦或32.4瓦/千克。一只体重0.0117千克的蝙蝠在接近最小功率飞行速度（4.2米/秒）时水平向前飞行所需的机械功率为0.14瓦（12.3瓦/千克），其中0.10瓦是空气动力学功率，0.042瓦是惯性功率。将其与我们根据花蜜摄入量估算的代谢功率需求结果进行比较，得出悬停飞行的机械效率为0.15，在接近最小功率速度的向前飞行中机械效率为0.11。
