Speaker: Rebecca Tyson
UBC Okanagan

Title: Modelling Modelling Anguilliform Swimming using the Immersed Boundary Method

Abstract: How does a given aquatic organism's wiggling result in
propulsion?  This has been well investigated in fish and in
microorganisms such as bacteria where the viscous or inertial terms of
the fluid equations can be ignored.  Less has been done at intermediate
Reynolds' Number, where he actual interaction between the organism's
musculature and the surrounding fluid is not well understood.  In this
talk we focus on the swimming behaviour of the nematode, a roundworm. 

The immersed boundary method lends itself very well to the study of organism locomotion 
in fluid. Movement of passive nematode-like structures has been successfully modeled in 
complex flows. Active swimming of small organisms has also been sucessfully modelled 
when the restlength of each muscle segment is prescribed, and an energy minimum for 
organism configuration obtained [2]. We are interested in modelling the development of 
swimming motion from rest, when motion is generated by the contraction of innervated 
muscle segments. 

We have developed a three-dimensional model for the body structure of
the nematode, which explicitly models the organism's musculature.  The
immersed boundary method is then used to communicate between the
nematode body and the surrounding fluid.   This model allows us to
study how the nematode musculature and surrounding fluid interact to
create propulsion of the nematode.   It also gives us the ability to
pursue fundamental questions about how organism structure affects the
swimming motion obtained and the fluid/muscle forces generated.