MULTISCALE SIMULATIONS OF FLUID FLOW FOR FINNED ELLIPTIC TUBE HEAT EXCHANGERS USING POROUS MEDIA APPROACH

摘要

A numerical finned elliptic tube heat exchanger (FETHE) model was proposed to investigate the hydrodynamic characteristics of a full-size FETHE by using the porous media approach. A finned elliptic tube heat exchanger was modeled in such a way that the details of the original structure were replaced by a simple geometry, so that the governing equations can be efficiently solved for a wide range of parameters. The first part of the paper reports there-dimensional numerical optimization results for two fins of elliptic tube arrangements, which are validated by direct comparison with experimental measurements with good agreement. The second part of the paper presents different numbers of fins or tubes arrangements to identify this method. The results are reported for air as the external fluid, in the range 1765≤Re_L≤12611, where L is the swept length of the fixed volume. The objective is to show the process of heat exchangers being modeled as a porous media and CFD being used in place of a detailed, experimental effort to obtain closure for the model. Apparently, in order to develop a universal fast running computational tool for complicated heat exchangers with multiple parameter, our current work is a step closer to this goal.