describe an algorithm for the study of inextensible elastic rods in three dimensions. Related work is being done con-A numerical algorithm for the three-dimensional dynamical viscous Kirchhoff rod model is presented. The algorithm includes pro-currently elsewhere [20]. In Sections 3, 4, and 5 an algoscribed extension and contact forces. Numerical results for several rithm for the dynamics of an inextensible twisted filament problems of biological significance are given, including dynamics will be developed. The principle points to be considered of the writhing (or supercoiling) instability in closed rods and the are the tracking of twist evolution and enforcement of approach to stable equilibria, and the dynamics and instability of inextensibility. Enforced inextensibility is then generalized open rods, particularly with regards to the self-assembly behavior of fibril structures composed of the bacteria bacillus subtilis. แฎ 1996 to proscribed extensibility. One phenomenon that can be Academic Press, Inc.
explored using this algorithm is the ''writhing'' or ''supercoiling'' instability observed in twisted elastic filaments. The energetics of the circular, uniformly twisted equilib-