CFD Simulation of a Multi-mesh Pulse Tube Regenerator

During the last two decades, inertance tube pulse tube cryocoolers (ITPTC) applications in astronauticsinstruments gained momentum due to their high reliability. Moreover, significant efforts were made inorder to improve ITPTCs operation. Investigations showed that most losses occur in the regeneratorpart. Due to complexity of physics of these losses, effects of the regenerator efficiency on thecryocooler performance were investigated in this work. Tocalculate heat transfer between solid matrixand acting fluid in the regenerator, Dual Energy Equation (DEE) model was used. Calculation ofentropy flow inside the regenerator showed that almost 85% of the energy losses are due to viscous andinertial losses besides most of the energy losses occuring in its hot end. Therefore, in order to optimizethe system, multi-mesh regenerator was studied. Results showed that under fixed CHX walltemperature of 150 (K), COP of the PTC with optimum multi-mesh regenerator is 1.07 times higherthan the value of uniform mesh regenerator ITPTC. A precise agreement was observed betweensimulation results and available experimental data published in the literature.