NUMERICAL STUDY OF GAS DYNAMICS INSIDE OF A PULSE TUBE REFRIGERATOR

摘要

Numerical simulation of the viscous compressible flow in a pulse tube is carried out to study the detail of the flow and fundamental mechanism of refrigeration. Axisymmetric two-dimensional Navier-Stokes equations are solved numerically by using finite volume method with implicit scheme. The phase difference in oscillating flow between the tube center and nearby the tube wall is observed by the simulation. The time variation of temperature profiles obtained by the simulation is in good agreement with experimental data. The particle path of working gas element and temperature difference between gas elements and tube side wall are evaluated in order to investigate the heat transfer from cold end to hot end. The secondary mass flux is observed by the particle path trace and the time-average mass flow. The simulation results suggest that the boundary layer on the tube wall might play an important role to the heat transfer.