SUMMARY

A numerical investigation has been carried out for a laminar incompressible reciprocating flow in a circular pipe with a finite length. An xamination of the governing equations and boundary conditions indicates that a sinusoidally reciprocating flow is governed by three similarity parameters: the kinetic Reynolds number Rew, the dimensionless oscillation amplitude Ao, and the length to diameter ratio L/D. The numerical solution for the velocity profiles of a developing reciprocating flow shows that at any instant of time, there exist three flow regimes in the pipe, namely, an entrance regime, a fully-developed regime and an exit regime. The numerical results for the ully-developed region are shown to be in excellent agreement with the analytical solution. Based on the numerical results, a correlation equation of the space-cycle averaged friction coefficient for a laminar developing reciprocating pipe flow has been obtained in terms of the three similarity parameters. KEY WORDS: reciprocating flow; a pipe of finite length; friction coefficient Although much theoretical work has been reported on the study of a periodically reciprocating flow in a pipe, it appears that most of previous research has been confined to th