Cooling performance optimization of tubular elastocaloric regenerators via thermo-fluid-mechanical coupled numerical modeling and simulations.

The elastocaloric refrigeration, utilizing the elastocaloric effect of NiTi shape memory alloys (SMA), presents a promising environmentally sustainable alternative to the traditional vapor compression refrigeration. Optimizing system performance is crucial for maximizing efficiency but hindered by experimental complexity. This study addresses the challenge by developing an experimentally validated, generalizable thermo-fluid-mechanical coupling numerical model and an accompanying optimization framework. Systematic simulations are performed to investigate the coupled influence of operating frequency, heat transfer fluid velocity, temperature span, and fluid channel thickness on specific cooling power (SCP). Results demonstrate a non-monotonic dependence of SCP on both frequency and fluid velocity across different temperature spans and fluid channel thicknesses, revealing an optimal combination that maximizes SCP by balancing heat transfer and heatregeneration efficiency. Additionally, this work introduces the normalized specific cooling power (NSCP) and then presents non-dimensional design principles for refrigeration systems that simultaneously incorporate thickness and temperature span through the optimization approach. The approach offers a novel and efficient (200 times faster) paradigm for designing and optimizing high-performance elastocaloric refrigeration systems with diverse refrigerants and system configurations, and successfully achieving a predicted NSCP that is at least 3 times higher than the existing experimental measurements.