Session: MSNDC-04/VIB-09-05: Nonlinear Dynamics of Systems and Structures

Paper Number: 118169

118169 - Dynamics and Constraint Loading in a Nonholonomic Model of Undulatory Locomotion 

In this work a nonholonomic model of undulatory locomotion is investigated.  The constraints are applied to emulate contact between a wheel and rigid flat surface for a land-based model, or to represent an ideal fluid-fin interaction under limiting conditions.  The focus is on two- and three-body models with various constraint arrangements, involving a possible holonomic slot constraint and one or more nonholonomic velocity constraints.   Locomotion is generated with an imposed oscillatory angle of an aft body relative to the head body.  Lagrange multipliers are used to determine constraint forces, including forces on wheels of the land-based system, and torques needed to maintain imposed oscillatory input.  The system is simulated with specific sets of parameters that generate regular motion.  Constraint forces are calculated and their behavior during a cycle of steady motion is examined.  Power and efficiency can also be calculated.  The effects of parameters on measures of performance and loading are studied.  To evaluate the model for the case of ideal fluid-fin interaction, computational fluid dynamics (CFD) simulations of undulatory swimming based on the direct numerical simulation (DNS) method are to be carried out for specific parameter sets, with body deformation and swim velocity that match the response conditions of the land-based model.   Since most of the fluid force that contributes to propulsion is generated at the fin, as a first step we will simulate flow around a fin with the imposed motion as extracted from the nonholonomic model.  The fluid force will then be measured from the simulation to compared with that obtained from Lagrange multipliers.  The comparison will allow us to evaluate the modeling of undulatory body-fin swim using a nonholonomic model.

Presenting Author: Jamal Ardister Michigan State University

Presenting Author Biography: Jamal Ardister is a doctoral student in Mechanical Engineering at Michigan State University.

Authors:

Jamal Ardister Michigan State University
Brian Feeny Michigan State University
Junlin Yuan Michigan State University