Heat Exchanger

Three-dimensional CFD simulations are carried out to investigate pressure drop and heat transfer characteristics of a heat exchanger model using GAMBIT and STAR-CCM+.  Model geometry is created in GAMBIT and it is meshed, simulated, and post-processed using STAR-CCM+. A comparison is done between steady and transient simulation results. The most accurate simulations for heat transfer in turbulent flow are more accurately simulated with the k-epsilon turbulence model. The main objective of this project is to find outlet pressure across heat exchanger, outlet temperature of hot fluid and thus characterize the heat exchanger. It is a known fact that CFD simulations of most of the heat exchangers are computationally intensive. To avoid high-end computations alternative approaches have been suggested to calculate pressure drop and as well as temperature drop.

 

Temperature Contours

 

Alternative approaches adopted to calculate pressure drop:

Porous media approach adopted to calculate pressure drop where entire fin region is assumed as porous medium and modelled accordingly.

 

Various alternative approaches deduced to calculate temperature drop:

Local Approach: Here local cut section of the geometry is taken and simulated by applying all boundary conditions and various parameters and results are interpreted for the complete geometry.

Heat Transfer Coefficient Approach: Heat transfer coefficient values are calculated for the fin region and used for a simpler geometry in assumption.

Entropy Generation Approach: Based on the relationship between temperature and entropy generation rate, temperatures at the inlet and outlet of heat exchanger can be determined.

       

       Pressure Contours