在伊比斯的飞行形成中,利用上游水和避免下游水,通过在伊比斯的飞行形成中逐步调节
Steven J Portugal1, Tatjana Y Hubel1, Johannes Fritz2
1Structure & Motion Laboratory, the Royal Veterinary College, University of London, Hatfield, Hertfordshire AL9 7TA, UK.
Nature
|January 17, 2014
概括
北方白头在V形状中优化了飞行位置. 鸟类在V飞行中表现出翼尖路径的一致性,最大限度地提高了能量效益,而不是在直接追逐中,反相飞可能会减少下水效应.
科学领域:
- 动物行为 动物行为
- 空气动力学 航空动力学
- 生物力学 生物力学
背景情况:
- 许多物种形成有组织的群体,以节省能量和改善运动.
- 人们普遍认为,鸟群中的V形形成为追随者提供了能量优势.
- 形成V的好处背后的精确空气动力学机制仍然不清楚.
研究的目的:
- 为了研究北方白头 (Geronticus eremita) 在V形飞行的空气动力学益处.
- 为了确定鸟类是否在V形状中最佳地定位自己.
- 分析翅膀跳动模式及其与空气动力学力之间的关系.
主要方法:
- 观测北方白头以V形飞行.
- 对单个鸟类相对于空气动力学预测的位置的分析.
- 在飞行过程中测量翼尖路径的连贯性和的分相.
主要成果:
- 在V形状的北方白头树采用空气动力学上最佳的位置.
- 鸟类在V飞行中表现出翅膀尖路径的一致性,在相位上翻动以最大限度地提高上水.
- 在直流的位置上,鸟类表现出反相,可能会减轻下水.
结论:
- 这些鸟类的V形飞行表明它们意识到周围的警觉结构.
- 鸟类表现出复杂的分阶段策略,以管理动态唤醒的翅膀拍打.
- 这些发现挑战了关于航空飞行协调复杂性的先前假设.
相关概念视频
Sound Waves: Interference
5.2K
Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...
5.2K
Absolute Motion Analysis- General Plane Motion
714
Visualize a drone, with its propellers spinning rapidly, hovering mid-air. The fascinating movements and operations of this drone can be comprehended by applying the principle of general plane motion.
As the drone's propellers rotate, an upward force is generated that counteracts the force of gravity, enabling the drone to lift off from the ground. This initial movement of the drone is along a straight path, representing a form of translational motion. In this phase, every point on the...
As the drone's propellers rotate, an upward force is generated that counteracts the force of gravity, enabling the drone to lift off from the ground. This initial movement of the drone is along a straight path, representing a form of translational motion. In this phase, every point on the...
714
Irrotational Flow
1.3K
Irrotational flow is characterized by fluid motion where particles do not rotate around their axes, resulting in zero vorticity. For a flow to be irrotational, the curl of the velocity field must be zero. This imposes specific conditions on velocity gradients. For instance, to maintain zero rotation about the z-axis, the gradient condition:
1.3K
Boundary Layer Characteristics
885
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
885
Lift
717
Lift is a fundamental aerodynamic force that acts perpendicular to the direction of airflow. It plays a central role in achieving and sustaining flight and in stabilizing various vehicles. Lift primarily originates from pressure differences created across surfaces, such as an airfoil. A lower pressure region forms above the wing, while a higher pressure region forms below it, generating an upward force. This differential results from the shape and orientation of the airfoil, enabling the wing...
717
Underflow Gates
537
Underflow gates are vital for controlling water flow in irrigation canals. The three main types of underflow gates — vertical, radial, and drum gates — serve different purposes while ensuring effective flow management. Vertical gates move up and down, generating a free-flowing water jet; radial gates pivot to regulate the flow; and drum gates rotate for precise adjustments. The flow through these gates is influenced by downstream conditions, resulting in free or drowned outflow.Free and...
537


