A correlation for heat transfer and flow friction characteristics of the offset strip fin heat exchanger

Abstract

The correlation for heat transfer and flow friction characteristics of fins is the basis for the optimization of heat exchangers, and it is of great importance to develop generally accurate formulas. To study the hydrodynamics and heat transfer characteristics of offset strip fins, Fluent is adopted to conduct the numerical simulation. Based on the calculation results of empirical correlations, the fluid constitutive model under different Reynolds numbers is determined in order to ensure the prediction efficiency and accuracy of offset strip fins. Good agreements are obtained between the numerical simulation and the Manglik & Bergles correlation, which verifies the validity and reliability of the numerical simulation method. Due to the fact that the traditional empirical formula is not able to cover the general specifications of Chinese domestic offset strip fins, the correlation of flow and heat transfer characteristics is improved based on the numerical simulation results and the industrial standard (Aluminum plate-fin heat exchanger NB/T 47006-2009). By coupling the Manglik & Bergles equation with the ALEX equation, a new relational expression of offset strip fins is proposed.