Local thermal equilibrium analysis of complete phase change process inside porous diffuser using NanoFluids

Abstract

This works implements an investigation on two-phase flow inside porous diffuser using Cu/water nanofluid instead of pure water. Interesting has been focused on how the using Cu/water affect the predictions of complete boiling process. Two-phase mixture model (TPMM), based on the assumptions of Local Thermal Equilibrium (LTE), has been converted to implement the actions of combining nano-fluid rather only water. The governing equations are solved by finite volume method. For the purpose of comparison, the solutions of temperature and liquid saturation, obtained employing Cu/water and only water as working fluid, have been displayed for a wide ranges of geometric parameters, operating parameters and properties of porous media to investigate impacts of using nanofluid. The findings illustrated that the adding Cu particle to water has a high influences on the heat diffusivity inside the diffuser as compared to the solutions of only water due to enhancing the axial diffusion. By employing Cu/water, the boiling and condensation fronts are considerably moved to downstream and upstream sections, respectively. The exit temperature is significantly reduced when utilizing Cu/water as compared to the only water solution. The findings of Cu/water show that the volume fraction of nano-fluid, operating conditions, geometric conditions and porous structure properties have large impacts on the locations of liquid and steam fronts. Accordingly, the nano-fluid is supposed as a safety key in the boiling applications since it improves the technique of heat transfer while simulating the complete boiling process.