Aerodynamics, Wing Biomechanics, and the Evolutionary Diversification of the Chiroptera

斯沃茨9723736进化论新颖性的起源和阐述构成了进化论研究最基本的领域之一。鉴于此，多年来，脊椎动物翅膀的结构、起源及其在飞行中的功能一直受到生物学家和工程师的关注。然而，对机翼结构部件内部形成的力的准确估计，以及对机翼形状和机翼运动模式的机械、空气动力学和能量意义的充分理解被忽视了。因此，在这项研究中，关于飞行器具多样化的进化起源和历史的知识仍然是原始的，我们将对大型蝙蝠的飞行进行建模，以分析空气动力学、力学和能量学。蝙蝠之所以被选为我们的研究生物体，是因为蝙蝠的特征是具有解剖组织(由弹性翼膜相互连接的刚性骨骼元素)，以生物逼真的方式建模相对简单。PI将使用我们的计算机模拟来问：1)在飞行过程中，机翼中的合力和力矩有多大？机翼内部产生的皮肤和骨骼应力有多大？2)机翼形态和运动学的小范围变化如何影响关节力和力矩以及机翼内部产生的皮肤和骨骼应力？3)机翼的形态和运动学特征如何影响机翼的机动性、结构稳定性和气动性能，以及飞行的机械功率？这些问题将通过实现一系列相互关联的目标来回答。一个机械和生物逼真的蝙蝠计算机模型将被开发出来，该模型以灰头飞狐小头翼蝠为基础，已经从这个物种获得了大量的功能和解剖学信息。模型的输入将包括解剖学信息、有关机翼组织的机械特性的数据以及机翼运动模式的三维描述。将构建一个详细的计算机模型，然后使用该模型生成有关机翼关节处形成的力、机翼骨骼和蒙皮中的应力、飞行的机械功率、骨骼承受屈曲的能力以及机翼的稳定性和机动性的信息。将进行灵敏度分析，以确定身体尺寸、机翼形状、飞行速度和生物力学特性对模型输出的相对影响。这项研究的结果将能够作为未来关于蝙蝠飞行的起源、多样性和适应的研究的基础。

Swartz 9723736 The origin and elaboration of evolutionary novelty comprise one of the most fundamental areas of evolutionary inquiry. In this light, the structure of vertebrate wings, their derivation, and their function during flight have attracted the attention of biologists and engineers for many years. However, the accurate estimation of the forces developed within the structural components of the wing, and the full understanding of the mechanical, aerodynamic, and energetic significance of the wing form and wing movement patterns have been neglected. As a consequence, knowledge of the evolutionary origins and history of diversification of flight apparatus remains primitive In this study, we will model the flight of a large bat to analyze aerodynamics, mechanics, and energetics. A bat has been selected as our study organism because bats are characterized by an anatomical organization (rigid bony elements interconnected by an elastic wing membrane) that is relatively simple to model in a biologically realistic fashion. The PI will the use our computer simulation to ask: 1) what are the magnitudes of the joint forces and moments in the wing during flight? how large are the skin and bone stresses developed within the wing?; 2) how do small-scale variations in wing morphology and kinematics affect the joint forces and moments and the skin and bone stresses developed within the wing? 3) what features of wing morphology and kinematics affect the maneuverability, structural stability and aerodynamic performance of the wing, and the mechanical power of flight? These questions will be answered by accomplishing a series of interrelated objectives. A mechanically and biologically realistic computer model of a flying bat will be developed, based on Pteropus poliocephalus, the gray-headed flying fox, a species from which a great deal of functional and anatomical information has already been obtained. Inputs into the model will include anatomical information, dat a concerning the mechanical properties of wing tissues, and three-dimensional descriptions of the movement patterns of the wing. A detailed computer model will be constructed, and then used to generate information about the forces developed at the wing joints, the stresses in the wing bones and skin, the mechanical power of flight, the ability of the bones to withstand buckling, and the stability and maneuverability of the wing. Sensitivity analyses will be carried out to determine the relative influence of body size, wing shape, flight speed, and biomechanical properties on the model outputs. The results of this study will be able to serve as the foundation for future studies concerning the origin, diversity, and adaptation of flight among bats.