CFD Simulation of a Multi-mesh Pulse Tube Regenerator

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