Numerical modeling of porous nozzles for regenerator of Stirling cryocooler.

A microcryogenic gas machine or microcryocooler is an important element of satellite navigation and communication systems. The main criterion of a cryocooler reliability is uptime at a given temperature level and a fixed value of the cooling capacity. The evaluation of a cryocooler uptime at the design stage by numerical analysis methods and taking into account the impact of various factors, including structural factors, at this time is an actual and difficult task. To solve this problem authors proposed to use the multivariate thermo gas dynamical analysis (MVTGA), the main principle of which is an integration of experience of experimental research and numerical simulation. The MVTGA has been developed by the authors of the paper, and the results of its application to analyze the microcooler design and thermodynamical processes in the microcooler regenerator are presented for the first time in this paper. The paper cites an example of application of MVTGA to analyze assembly units of a cryocooler as well as a mathematical 3D modeling of the structure and hydrodynamics of a porous regenerator as a main unit, accumulating risks. The paper also compares the results of a numerical study of the dependence of the hydraulic resistance of the simulated regenerator on the Reynolds number with the results of the calculation using correlation dependences of foreigner researchers.