报告题目：

Secrets of swimming in sand

报告人: 

Dr. Yang Ding

Department of Aerospace and Mechanical Engineering, University of Southern California

时间：2014年1月8日(周三)  10:00                   

地点：中国科学院力学研究所344会议室

报告摘要：

   Locomotion within granular media like sand, soil and debris that display both solid and fluid-like behavior is challenging and not well understood. Here I summarize my modeling efforts to  understand the swimming of the sandfish lizard in sand. High speed x-ray imaging showed that the 10 cm-long sandfish swims at 2 body-lengths/sec within sand by propagating an undulatory traveling wave down the body. We developed an empirical resistive force model with granular forces measured from experiments. The model correctly predicts the animal's wave efficiency (ratio of forward speed to wave speed) as approximately 0.5. The model also explains the muscle activation pattern observed on sandfish and solved a long-standing puzzle of undulatory swimmers. The empirical model agrees with a more detailed numerical simulation: a multi-segment model of the sandfish coupled to a multi-particle discrete element method (DEM) simulation of the granular medium. We use the principles discovered to construct a sand-swimming physical model (a robot) which, like in our empirical and multi-particle numerical models, swims fastest using the preferred sandfish wave pattern.

报告人简介：

   Yang Ding（丁阳）本科毕业于中国科技大学, 2011年在佐治亚理工学院(Georgia Tech)获得物理博士学位，现于美国南加州大学(University of Southern California)航空与机械系做博士后。丁阳的研究方向为动物运动力学和生物与流体的相互作用。他曾在Science、 PNAS等杂志发表论文, 也曾被JFM、 J. R. Soc. Interface等杂志邀请审稿。