Modeling of Flow Distribution in Multi-Branch Channels using the Second Law of Thermodynamics

Flow maldistribution has been an on-going issue that limits the full potential attainment of microchannel heat exchangers (MCHX). The underlying cause is the lack of theoretical understanding due to many complex interdependent factors at play. This results to high variability leading to a mathematical challenge of representing and solving the physical system. Hence, the available studies in the literature are limited to experimental investigations or CFD models that are case specific. This paper reports the method of incorporating a pressure drop model and integrating a variational formulation by extremizing the entropy generation rate. The extremum principle points at the maximum entropy production rate toward a stationary state, hence providing a general representation of the phenomenon which is unrestrained from limitations to a specific working fluid and structural geometry of the MCHX. Distribution results are investigated for different inlet conditions. A first comparison to experimental data shows a fair prediction accuracy.