Aerodynamics of Passive Flight and Probability of Landing Sites

点击翻译按钮获取中文摘要

Accurate prediction of the flight range and landing site of an object descending under the influence of gravitational and aerodynamic forces is relevant to many engineering and science applications. Examples range from forecasting the touchdown locations of re-entry space vehicles to understanding the settlement patterns of marine larvae and their influence on marine population dynamics. While the descent motion follows the laws of classical mechanics, the delicate interplay between the fluid medium and the geometric and material properties of the descending objects makes the exact landing site difficult to predict a priori and, thus, best treated as probabilistic. This award supports fundamental research that aims to develop an experimentally and mathematically tractable framework for studying the coupling between the mechanics of objects descending passively in a fluid medium and the probabilistic outcome of landing sites. This research will draw from techniques developed in several disciplines including solid-fluid interactions, dynamical systems, and probabilistic modeling. This multi-disciplinary research approach will be combined with outreach efforts in the greater Los Angeles area to help broaden the participation of underrepresented groups in research and positively impact engineering and science education.The descent motion of objects falling in a fluid medium is generally complex, even for regularly shaped objects such as coins and cards. For such objects, four types of descent trajectories have been identified: steady, fluttering, chaotic, or tumbling, depending on the object and fluid properties. This research team will explore the dependence of the probability distribution of landing sites on the type of descent trajectories through carefully designed experiments as well as by developing mathematical and computational models of increasing levels of fidelity to the physical systems. Research efforts will also focus on establishing design principles that an object should fulfill in order to achieve a desired distribution of landing sites.