Dept. of Mechanical Engineering Graduate Seminar

PRESENTATION: Natural swimmers and flyers exhibit exceptional propulsive performance by harnessing complex unsteady flows through mechanisms such as oscillating fish tails and flapping insect wings. To engineer high-performance bio-inspired robots, effective control of propulsors in these unsteady regimes is essential. However, this control problem is challenging due to two primary difficulties: 1) the high-dimensional parameter space governing kinematics and shape, which complicates optimization efforts, and 2) the inherently nonlinear Navier–Stokes equations that govern the fluid dynamics, limiting the applicability of linear analysis tools.

To overcome these hurdles, we have developed an efficient, high-fidelity adjoint-based optimization framework tailored to unsteady flows around moving propulsors. This presentation discusses the development of the adjoint-based optimal control algorithm and demonstrates its application to two key problems in bio-inspired propulsion: identifying optimal swimming gaits for fish-like systems and optimal flapping kinematics for insects and birds.

PRESENTER: Xuanhong An is an Assistant Professor in the College of Aeronautics and Engineering at Kent State University. His research focuses on developing flight control systems for extreme flight conditions, investigating the flow physics behind complex flow phenomena and optimizing high-dimensional dynamical systems (especially fluid dynamical systems). He earned his Ph.D. in Mechanical and Aerospace Engineering from the Illinois Institute of Technology, advised by Dr. David Williams. Subsequently, he worked as a postdoctoral research associate in Dr. Clarence Rowley’s laboratory at Princeton University.