Associate Professor Aerospace and Mechanical Engineering University of Southern California
1997: B.E., Mechanical Engineering, American University of Beirut
1999: M.S., Mechanical Engineering, University of California at Berkeley
2003: Ph.D., Mechanical Engineering, University of California at Berkeley
2003-2005: Postdoctoral Scholar, Control and Dynamical Systems, California Institute of Technology
Since 2010: Associate Professor, Department of Aerospace & Mechanical Engineering 2005-2010: Assistant Professor, Department of Aerospace & Mechanical Engineering
Honors and Awards:
2007: National Science Foundation Career Award, "Modeling and Control of Solid-Fluid Interactions in Aquatic Locomotion"
Since 2011: Zohrab A. Kaprielien Fellow in Engineering
Jing F., Kanso E.
Stability of Underwater Periodic Locomotion
2013, vol. 18, no. 4, pp. 380-393
Most aquatic vertebrates swim by lateral flapping of their bodies and caudal fins. While much effort has been devoted to understanding the flapping kinematics and its influence on the swimming efficiency, little is known about the stability (or lack of) of periodic swimming. It is believed that stability limits maneuverability and body designs/flapping motions that are adapted for stable swimming are not suitable for high maneuverability and vice versa. In this paper, we consider a simplified model of a planar elliptic body undergoing prescribed periodic heaving and pitching in potential flow. We show that periodic locomotion can be achieved due to the resulting hydrodynamic forces, and its value depends on several parameters including the aspect ratio of the body, the amplitudes and phases of the prescribed flapping.We obtain closedform solutions for the locomotion and efficiency for small flapping amplitudes, and numerical results for finite flapping amplitudes. This efficiency analysis results in optimal parameter values that are in agreement with values reported for some carangiform fish. We then study the stability of the (finite amplitude flapping) periodic locomotion using Floquet theory. We find that stability depends nonlinearly on all parameters. Interesting trends of switching between stable and unstable motions emerge and evolve as we continuously vary the parameter values. This suggests that, for live organisms that control their flapping motion, maneuverability and stability need not be thought of as disjoint properties, rather the organism may manipulate its motion in favor of one or the other depending on the task at hand.
Vankerschaver J., Kanso E., Marsden J. E.
The dynamics of a rigid body in potential flow with circulation
2010, vol. 15, no. 4-5, pp. 606-629
We consider the motion of a two-dimensional body of arbitrary shape in a planar irrotational, incompressible fluid with a given amount of circulation around the body. We derive the equations of motion for this system by performing symplectic reduction with respect to the group of volume-preserving diffeomorphisms and obtain the relevant Poisson structures after a further Poisson reduction with respect to the group of translations and rotations. In this way, we recover the equations of motion given for this system by Chaplygin and Lamb, and we give a geometric interpretation for the Kutta–Zhukowski force as a curvature-related effect. In addition, we show that the motion of a rigid body with circulation can be understood as a geodesic flow on a central extension of the special Euclidian group $SE(2)$, and we relate the cocycle in the description of this central extension to a certain curvature tensor.