An Eulerian-Lagrangian model to study the operating mechanism of Stirling pulse tube refrigerators

This paper aims to study the operating mechanism of stirling pulse tube refrigerators (ptrs) by tracing the characteristics of working gas elements at the cold end of the system using both eulerian and eulerian-lagrangian (e-l) methods. the main objective of the investigation is to demonstrate non-symmetry effects in the pulse tube section of the system. elemental cyclic-enthalpy transfer of simple (s), double-inlet (di) and multi-mesh regenerator (mm) ptrs are also investigated to demonstrate the effects of di and mm systems on the refrigeration mechanism of ptrs. it is shown that the elemental cyclic-enthalpy transfer of sptr is less than that of diptr, mmptr and mmdiptr. also, its elemental cyclic-temperature reduction is more than the others, because the mass flow rate upon the cold end of the sptr is less than the others. regarding the reduction of losses in diptr and mmptr, their cold end mean pressure and density increase, and this, consequently, leads the cold end mass flow rate and cyclic-enthalpy transfer to increase. increase in the enthalpy transfer of mm-ptr, mm-diptr and diptr consequently improves their cooling performance.