The internal physical processes and performance of a two-stage pulse tube cooler operating at 4 K-temperature region are numerically analyzed by a new mixed Eulerian-Lagrangian computational model. The detailed time-v...The internal physical processes and performance of a two-stage pulse tube cooler operating at 4 K-temperature region are numerically analyzed by a new mixed Eulerian-Lagrangian computational model. The detailed time-variations of gas temperature, pressure, mass flow rate, enthalpy flow in a cycle, in the first and the second-stage regenerators are presented in the paper. The behavior of the various gas elements, which enter the pulse tube from its cold end has been revealed and discussed. More attention is paid to the effects of different regenerative materials on the performance of the 4 K two-stage pulse tube cooler.展开更多
A new mixed Eulerian-Lagrangian computational model for simulating and visualizing the internal processes and the variations of dynamic parameters of a two-stage pulse tube cooler (PTC) operating at 4 K-temperature re...A new mixed Eulerian-Lagrangian computational model for simulating and visualizing the internal processes and the variations of dynamic parameters of a two-stage pulse tube cooler (PTC) operating at 4 K-temperature region has been developed. We use the Lagrangian method, a set of moving grids, to follow the exact tracks of gas particles as they move with pressure oscillation in the pulse tube to avoid any numerical false diffusion. The Eulerian approach, a set of fixed computational grids, is used to simulate the variations of dynamic parameters in the regenerator. A variety of physical factors, such as real thermal properties of helium, multi-layered magnetic regenerative materials, pressure drop and heat transfer in the regenerator, and heat exchangers, are taken into account in this model. The present modeling is very effective for visualizing the internal physical processes in 4 K-pulse tube coolers.展开更多
文摘The internal physical processes and performance of a two-stage pulse tube cooler operating at 4 K-temperature region are numerically analyzed by a new mixed Eulerian-Lagrangian computational model. The detailed time-variations of gas temperature, pressure, mass flow rate, enthalpy flow in a cycle, in the first and the second-stage regenerators are presented in the paper. The behavior of the various gas elements, which enter the pulse tube from its cold end has been revealed and discussed. More attention is paid to the effects of different regenerative materials on the performance of the 4 K two-stage pulse tube cooler.
文摘A new mixed Eulerian-Lagrangian computational model for simulating and visualizing the internal processes and the variations of dynamic parameters of a two-stage pulse tube cooler (PTC) operating at 4 K-temperature region has been developed. We use the Lagrangian method, a set of moving grids, to follow the exact tracks of gas particles as they move with pressure oscillation in the pulse tube to avoid any numerical false diffusion. The Eulerian approach, a set of fixed computational grids, is used to simulate the variations of dynamic parameters in the regenerator. A variety of physical factors, such as real thermal properties of helium, multi-layered magnetic regenerative materials, pressure drop and heat transfer in the regenerator, and heat exchangers, are taken into account in this model. The present modeling is very effective for visualizing the internal physical processes in 4 K-pulse tube coolers.
