CFD ANALYSIS OF TWO PHASE FLOW INSIDE A HORIZONTAL PIPE

Abstract

The present research is endeavored on the estimation of total frictional pressure drop inside a smooth horizontal pipe for two-phase flow of refrigerant R410a under adiabatic condition at a given saturated temperature of 40 C (i.e. for condensing flow of refrigerant) at different quality of vapour and at two different mass fluxes of 350 kg/m2s and 1055 kg/m2s by using CFD modeling. Analysis results are then compared with homogeneous and separation flow models of multiphase flows as explained in literature and chapter 3 of this report. The analysis of single phase flows and the two-phase flows through different components and fittings is essential for the regulation and application of few heat transfer devices such as condensers, evaporators, and some heat exchangers needed in refrigeration and air conditioning units. For all these, single-phase flow may emerge as superheated vapors in the evaporator and condenser or as sub cooled liquid in the condenser, but still the two-phase flow is the dominant part of these coils. In drafting of such components, the calculation of pressure gradient is also as necessary as the heat transfer coefficient. The results of CFD analysis found satisfactory closure to the Chisholm correlation at low mass flux with 07.96 % of average deviation from CFD analysis results and for higher mass flux CFD results are best predicted by Muller Steinhagen - Heck Correlation with 04.04% average deviation from the CFD analysis results but the results for Lockhart-Martinelli and Gronnerud Correlations are deviated largely in both the cases.