The objective of this research has been to model the bacterial flagellum in a viscous hydrodynamic environment using an explicit particle-bases model that captures both the elastic nature of the filament and the flow of the fluid surrounding it. We use a hybrid method of the elastic network model and smooth particle hydrodynamics to capture the physics of the bacterial propulsion and the nature of the flow field. In particular, we make effort to incorporate at a CG level the molecular organization of the flagellar filament by simulating the flagellum as a helical tube of 11 protofilaments.

 

     Each of these protofilaments is represented by a collection of material points that are representative of the flagellum proteins--the building blocks of the bacterial flagellum. Thee material points are connected to each other through a network of elastic springs. The overall material properties of the flagellum are then matched to the model by relating the experimental value for either the flexural rigidity or the twist modulus to the stiffness constant of the elastic network model. this model is then coupled to a particle based Lagrangian method of smooth particle hydrodynamics to study the flagellar motion in a low Reynolds number hydrodynamic environment.