Oscillatory flow in microporous media applied in pulse – tube and Stirling – cycle cryocooler regenerators

摘要: Abstract Pulse tube and Stirling cryocoolers are widely used in aerospace other high-demand application. A key component these systems is the regenerator, which typically a microporous metallic structure that subject to periodic flow of cryogenic fluid. The thermal hydrodynamic irreversibilities play crucial roles with respect efficiency aforementioned cycles, poorly understood, however. In this investigation experiments were performed where pressure drop associated steady-periodic (axial lateral (radial)) flows helium test sections packed several pulse cryocooler regenerator fillers measured under ambient temperature conditions. computational fluid dynamic (CFD) – assisted method was developed for analysis interpretation experimental data, whereby permeability inertial coefficients lead agreement between data predictions CFD simulations iteratively obtained. directional Forchheimer thus obtained tested fillers, found be independent frequency oscillations range 5–60 Hz. results also show oscillatory parameters different than steady-flow representing similar