Pressure drop and friction factor study for an airfoil-fin printed circuit heat exchanger using experimental and numerical techniques

Abstract

The airfoil-fin, Printed Circuit Heat Exchanger (PCHE) has been considered to be a key candidate for nuclear energy, Concentrated Solar Power, and several power conversion cycle applications, using different heat transfer fluids like molten salts, supercritical-CO2, and helium gas among others. In this study, differential pressure and flow rate measurements have been experimentally conducted across several axial spans on the hot side plate of an airfoil-fin PCHE. These experimental investigations have been performed across a wide range of Reynolds numbers (Re = 2,000–25,000), on a fully modular test rig, which utilizes additive manufacturing techniques. Furthermore, Reynolds-Averaged Navier–Stokes simulations have been performed, where the experimental work has been used to identify the boundary conditions. The numerical simulations have been used to predict the pressure drop and characterize friction factor correlations across an extended range of Reynolds numbers (Re = 100–100,000), and have been found to be in good agreement with the experimental investigations. These numerical simulations can be used to study the velocity and pressure fields in an airfoil-fin micro-channel geometry. Additionally, they can also be used to study the correlation between friction factor and Reynolds number across different flow regimes, that lays the foundation for future heat exchanger design studies.