Oscillatory Flow through a Convergent Tube

Abstract

This paper deals with the laminar laminar oscillatory flow of an incompressible fluid through a slightly convergent tube. The velocity distributions in the convergent tube, whose convergent angles are in the range of 2-4°, are measured by a Laser Doppler Velocimeter. The flow in the convergent tube is numerically analysed by a finite difference method (SOR) without neglecting the convective terms in the Navier-Stokes equation. Experimental results agreed well with the numerical ones. The velocity profile of a laminar oscillatory flow in the convergent tubes is quite different from the velocity profile in a straight tube of circular cross section, even if the convergent angle is very small. The instantaneous pressure distribution in the convergent tube is as uniform at each cross section as in a straight circular tube.