Design Optimization and study of Fluid Dynamics for the Porous, Multi-Layered Baffled Porous and Hybrid Regenerators for Cryogenic Applications

Regenerators play a crucial role in cryocoolers by efficiently transferring heat between a working fluid and the matrix material, thereby enhancing cooling efficiency. The paper describes the modelling, design optimization, and fluid dynamics of various types of porous structured regenerators, such as SS, multi-layered baffle, and hybrid regenerators, in an attempt to fabricate them using an additive manufacturing process. The regenerator’s physical dimensions are optimized to ensure retrofit compatibility with existing cryogenic systems at Tata Institute of Fundamental Research (TIFR) Mumbai, facilitating seamless integration and performance enhancement of an appropriate regenerator. The selection of a body-centred cubic (BCC) lattice structure, through FEA analysis, aims to optimize the regenerator design based on factors such as porosity and surface area concerning fluid volume interaction. Integrating baffles (multi-layered porous structure) into the structured porous regenerator aims to extend fluid-matrix interaction, thereby improving heat transfer efficiency and overall performance. Developing a hybrid regenerator utilizing lead at the cold end and stainless steel at the hot end aims to achieve lower operational temperatures, enhancing cooling capabilities for extreme cryogenic applications. CFD analysis using ANSYS 24.1 software enables comprehensive evaluation of temperature, pressure, and velocity variations along the regenerator length, providing insights into fluid dynamics and performance optimization. The results are cross-verified in REGEN 3.3 software, which ensures robustness and accuracy in predicting regenerator behaviour and performance under varying operational conditions.