Role of wing color and seasonal changes in ambient temperature and solar irradiation on predicted flight efficiency of the Albatross
Role of wing color and seasonal changes in ambient temperature and solar irradiation on predicted flight efficiency of the Albatross
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DOI：
10.1016/j.jtherbio.2017.11.002
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发表时间：
2018-01-01
影响因子：
2.7
通讯作者：
Abdelkefi, A.
中科院分区：
文献类型：
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作者：
Hassanalian, M.;Throneberry, G.;Abdelkefi, A.
候鸟翅膀的减阻对其飞行效率至关重要。机翼颜色会影响太阳辐射的吸收，从而影响阻力，但这方面的研究很少。为此，本研究提出了无动力飞行模式下候鸟翅膀颜色热效应引起的阻力减小。考虑到信天翁的这种自然现象是候鸟的一个例子，并将能量平衡应用于这一生物系统，在夏季和冬季对信天翁的翅膀进行热分析，以获得不同季节的环境温度和气候条件所带来的不同空气密度、粘度和翅膀表面温度范围，并研究它们的影响。我们使用了信天翁翅膀的确切形状，并考虑了九种不同的翅膀颜色，以便更好地理解不同颜色的吸收率对空气动力性能变化的影响。由于太阳辐照值较高，热效应在夏季比冬季更为重要，夏季将机翼颜色从浅白色变为深黑色，最大阻力减少了7.8%。结果表明，翅膀颜色较深的信天翁飞行效率更高（升阻比不变，减阻率不变），并且由于这种减阻率而具有更好的续航能力。
Drag reduction of the wings of migrating birds is crucial to their flight efficiency. Wing color impacts absorption of solar irradiation which may affect drag but there is little known in this area. To this end, the drag reduction induced by the thermal effect of the wing color of migrating birds with unpowered flight modes is presented in this study. Considering this natural phenomenon in the albatross as an example of migrating birds, and applying an energy balance for this biological system, a thermal analysis is performed on the wings during the summer and winter to obtain, different ranges of air density, viscosity, and wing surface temperature brought about from a range of ambient temperatures and climatic conditions seen in different seasons and to study their effects. The exact shape of the albatross wing is used and nine different wing colors are considered in order to gain a better understanding of the effect different colors' absorptivities make on the change in aerodynamic performances. The thermal effect is found to be more important during the summer than during the winter due to the higher values of solar irradiation and a maximum drag reduction of 7.8% is found in summer changing the wing color from light white to dark black. The obtained results show that albatrosses with darker colored wings are more efficient (constant lift to drag ratio and drag reduction) and have better endurance due to this drag reduction.