The 10th Asian Symposium on Computational Heat Transfer and Fluid Flow ( ASCHT2025)

Miniature Stirling cryocoolers are vital for modern high-operating-temperature infrared detector systems due to their precise cooling control and compliance with strict SWaP (Size, Weight, and Power) requirements. This study presents a CFD-assisted numerical simulation of a SWaP-refined miniature Stirling cryocooler to investigate its cooldown behavior, cooling load, and pressure drop. In this simulation, a linear elastic solid dynamic mesh model was adopted for piston and displacer motion, while temperature-dependent properties of the working fluid and matrix material were incorporated. Two user-defined functions (UDFs) were implemented to control and synchronize piston and displacer motion at the specified phase angle. The results show that with the refined SWaP design geometrical parameters, a reciprocation frequency of 45 Hz, a filling pressure of 3.5 MPa, and the regenerator porosity of 0.692 with mesh size #325, the cryocooler achieved the required cooling temperature of 150 K. To determine the cooling capacity, the cryocooler sustained a temperature of 150 K while gradually applying heat loads of 0.1 W, 0.2 W, 0.3 W, 0.4 W, and 0.5 W at the cold tip. These simulation results can be used to verify and validate the geometrical and operational parameters of the SWaP-designed cryocooler, supporting its progression from the design stage to the development stage.

cryocooler, detectors, dynamic mesh, infrared, miniature, Stirling