| 摘 要： | This paper deals with the motion of viscous liquid column with finitelength and two free surfaces in a vertical straight capillary tube.It isassumed that fluid is Newtonian.Linearizing the boundary conditions,analytic expressions in the form of infinite series have been obtainedfor velocity,plessure and free surface at low Reynolds number.Thenumerical calculation is carried out for a set of cylinder’s length ofwater and blood.It has been revealed that there are considerable cir-culating currents at the upper and lower meniscuses.Its maximum ve-locity is about57%of the average velocity of the mainstream.Iner-tial effect is also studied in this paper.Using the time-dependent methodin finite difference techniques,numerical solution of the correspondiugnonlinear equation at Re≤24.5 is computed.Comparing it with analyticexact solution at low Reynolds number shows that inertial effect isnegligible provided Re≤24.5.
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