Analysis of heat transfer in cryogenic regenerator using developed code and comparison of the results with simulation by FLUENT

Compact-sized, efficient cryo-coolers are widely used in missiles and other devices. The cooling performance of cryo-cooler largely depends on the regenerator and the cooling performance of regenerator depends on non-dimensional parameters, namely heat transfer unit (NTU), heat capacity ratio, thermal losses due to longitudinal conduction etc. A code has been developed to analyze the energy balance of the fluid and matrix and solve the equations using Parallel-Flow model for both ideal and non-ideal regenerators. The effects of nondimensional parameters on inefficiency were found out quantitatively through the developed code. For comparison, porous media simulation by commercial solver FLUENT was also done. The results generated by the code (temperature profile, heat transfer and inefficiency) were in good agreement with those of FLUENT simulations as well as the data documented in the literature. Thus, the developed code can be used as a tool for initial design of cryocoolers and optimizing the performance by selecting the matrix material, temperature swing, NTU, porosity etc.