Correlation of fiber shape measures with dilute suspension properties

The correlations between the intrinsic viscosity of fiber suspensions and 17 measures of fiber shape were inve­ stigated. The intrinsic viscosities of suspensions of fibers with various shapes and aspect ratios were determined numerically. The shapes studied include different degrees of fiber curvature, angular bends, helical shapes, randomly generated shapes, and others. The shape measure that correlated most strongly with intrinsic viscosity was an invariant of the hydrodynamic resis­ tance tensor; this invariant is related to the hydrodynamic drag coefficients on a fiber translating in the three principal direc­ tions. This measure can be computed from 3D images of real fibers, and could potentially be a useful quantity for describing fiber shape. These results also suggest that experimentallymeasured intrinsic viscosities can be used to characterize fiber shape, either directly or by extracting the invariant from experi­ mental data.