Modelling and simulation of two-phase flow inside porous pipe evaporator using Cu-Water nano-fluid

Abstract

In this article, the fully boiling process inside pipe filled with porous media has been numerically investigated using Cu/water nanofluid. Two-Phase Mixture Model (TPMM) has been modified to include the impacts of adding nano-fluid instead of pure water under Local Thermal Equilibrium (LTE) model. The mathematical formulation have been solved utilising finite volume method on fixed grid mesh. Impacts of geometric parameters, operating parameters and properties of porous media on the profiles of temperature and liquid saturation have been presented. The obtained solutions using Cu/water have been compared with those obtained using pure water and hence, results clearly demonstrate that the using Cu/water strongly enhance the diffusive heat inside the pipe. The results of Cu/water indicate that the mixture region is further prolonged in the upstream and downstream parts in comparison with the results that obtained using pure water due to add further heat to the domain occurring from rising the axial diffusion. The using of Cu/water leads to move the boiling front considerably towards the pipe outlet and the exit temperature is substantially reduced as compared to the pure water case. Results of Cu/water also display that the solid volume fraction, heating and flow conditions, porous structure properties and geometric parameters have high influences on the starting and ending of mixture region. Based on this, the nanofluid can be used while modelling the fully boiling process since it supplies an extra technique for heat transfer and considers as a safety factor, particularly in the applications that required very high temperature.