Pages 75-76
The deformation of a flagellum of Vibrio alginolyticus, single-flagellate bacteria, is analyzed theoretically assuming the form of the flagellum to be a circular helix. The viscous force exerted on the flagellum in aqueous fluid is estimated applying the resistive-force theory based on the Stokes flow. The moments of force in the flagellum are described in analytical expressions and also the curvature and the torsion of the deformed flagellum are expressed analytically according to the Kirchhoff rod model. The deformation of the flagellum is obtained numerically solving evolution equations which describe a space curve with modified curvature and torsion. Comparing variations of the pitch of helical flagella between the numerical solutions and the results of measurement, the elastic bending coefficient for the flagellum of Vibrio alginolyticus is estimated.
