Computational fluid simulation of non-Newtonian two-phase fluid flow through a channel with a cavity

Abstract

In this paper, the numerical solution of non-Newtonian two-phase fluid-flow through a channel with a cavity was studied. Carreau-Yasuda non-Newtonian model which represents well the dependence of stress on shear rate was used and the effect of n index of the model and the effect of input Reynolds on the attribution of flow were considered. Governing equations were discretized using the finite volume method on staggered grid and the form of allocating flow parameters on staggered grid is based on marker and cell method. The QUICK scheme is employed for the convection terms in the momentum equations, also the convection term is discretized by using the hybrid upwind-central scheme. In order to increase the accuracy of making discrete, second order Van Leer accuracy method was used. For mixed solution of velocity-pressure field SIMPLEC algorithm was used and for pressure correction equation iteratively line-by-line TDMA solution procedure and the strongly implicit procedure was used. As the results show, by increasing Reynolds number, the time of sweeping the non-Newtonian fluid inside the cavity decreases, the velocity of Newtonian fluid increases and the pressure decreases. In the second section, by increasing n index, the velocity increases and the volume fraction of non-Newtonian fluid after cavity increases and by increasing velocity, the pressure decreases. Also changes in the velocity, pressure and volume fraction of fluids inside the channel and cavity are more sensible to changing the Reynolds number instead of changing n index.

Opposing Mixed Convection in an Open Parallelogram Cavity with the Horizontal Channel: Effects of the Heat Source Length and Location

“…Two-dimensional laminar mixed convection in a hollow connected to a horizontal channel was investigated statistically by Ahmadi and Farsani [15]. A cavity-enclosed conduit was subjected to a two-phase flow of a non-Newtonian fluid.…”

A computational study of curvature effect on pressure drop of gas-liquid two-phase flow through 90 degree elbow

“…While there are those who acknowledge the existence of this effect [14,15]. Ahmadi, et al [16] studied two-phase flow and cavity through a channel using computational analysis and investigated the effect of input Reynolds and flow properties. Aungi and Yuwono [17] reported that the multiphase flow pattern through and around the elbow bend was perhaps more dependent on liquid superficial velocity and also affected by gas volume fraction at high liquid velocity for the same operation condition.…”

A review of convective heat transfer in cavity-channel assemblies

“…A stereoscopic time-resolved particle image velocimetry (TR-PIV) was used to assess the thermal effects on the flow.They concluded that the increase in Re lowers the critical Richardson number above which the flow was no longer encapsulated. Ahmadi and Farsani[39], 2020, involved the non-Newtonian fluid in a 2D laminar mixed convection in a cavity linked with a horizontal channel. A non-Newtonian two phase fluid flow was entered the channel with the cavity.…”