CFD And Thermal Analysis For Characterization Of Fins Of Evaporator In Two Phase Flow Of Vapor Cycle System For Aerospace Application

Abstract

Improvement in heat transfer using different types of secondary fin area is well known in the field of design and development of compact heat exchanger where the size and weight are the main design drivers for the aerospace application. Lot of literature is available for the single-phase heat transfer process in a compact heat exchanger with various types of fins and their correlations. But when it comes to two-phase flow there are some experimental results along with approximations and/or empirical factors applied to the single-flow estimations.  The main purpose of this work is to study the improvement in the performance of a compact heat exchanger using offset strip fins in terms of heat transfer coefficient using CFD technique. The methodology used for performance improvement starts with study of existing two-phase flow in evaporator and improvement in heat transfer area using offset strip fin. ANSYS FLUENT 18.2 is used to study the performance of the evaporator. The results of detailed Fluent analysis bring out the surface heat transfer coefficient and the temperature at inlet, outlet and wall due to the given heat flux condition. These values play an important role in calculating the heat load and the estimates are very useful in design of a two-phase compact heat exchanger without resorting to costly experimentation.