Abstract and Applied Analysis
Volume 2004 (2004), Issue 4, Pages 347-360

Comparison of differential representations for radially symmetric Stokes flow

George Dassios1,2 and Panayiotis Vafeas1,2

1Division of Applied Mathematics, Department of Chemical Engineering, University of Patras, Patras 26504, Greece
2Institute of Chemical Engineering and High Temperature Chemical Processes (ICE/HT), Foundation for Research Technology-Hellas (FORTH), University of Patras, Patras 26504, Greece

Received 10 September 2002

Copyright © 2004 George Dassios and Panayiotis Vafeas. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Papkovich and Neuber (PN), and Palaniappan, Nigam, Amaranath, and Usha (PNAU) proposed two different representations of the velocity and the pressure fields in Stokes flow, in terms of harmonic and biharmonic functions, which form a practical tool for many important physical applications. One is the particle-in-cell model for Stokes flow through a swarm of particles. Most of the analytical models in this realm consider spherical particles since for many interior and exterior flow problems involving small particles, spherical geometry provides a very good approximation. In the interest of producing ready-to-use basic functions for Stokes flow, we calculate the PNAU and the PN eigensolutions generated by the appropriate eigenfunctions, and the full series expansion is provided. We obtain connection formulae by which we can transform any solution of the Stokes system from the PN to the PNAU eigenform. This procedure shows that any PNAU eigenform corresponds to a combination of PN eigenfunctions, a fact that reflects the flexibility of the second representation. Hence, the advantage of the PN representation as it compares to the PNAU solution is obvious. An application is included, which solves the problem of the flow in a fluid cell filling the space between two concentric spherical surfaces with Kuwabara-type boundary conditions.