Model developed to study regenerative cooling systems using caloric materials

Caloric materials generate cooling effects when cyclically acted upon by magnetic, electric or mechanical forces. They demonstrate a strong potential as an alternative material for regenerative cooling technologies. When combined with a heat transfer fluid, these materials can move heat efficiently throughout a refrigeration system.

Sebald et al. developed an analytical model to simulate active regenerative cooling systems using caloric materials. Their model, which can be applied to any caloric material, was experimentally verified with natural rubber as the elastocaloric material.

“Cooling systems using natural rubber require further optimization and scaling up in order to have parallel multiple tubes. This would both help solve thermal boundary imperfections and achieve higher cooling power,” said author Gael Sebald.

Their analytical model examined and tested the properties of a regenerative cooling device in terms of its caloric material, fluid and geometry of the device. This was done by using a heat transfer equation to solve for harmonic excitation along the direction perpendicular to caloric materials layers separated by fluid layers and along an axis parallel to the layers.

“Our results lead to some interesting questions related to heat transfer in harmonic regime and on the exact mechanisms of the generation of a mean heat flux along one direction,” said Sebald. “The proposed approach identifies the importance of the product of fluid velocity by its harmonic temperature variations as well as the impact of the harmonic thermal boundary layer.”

The authors believe this model can lead to the optimization of regenerative cooling technologies that use caloric materials and may serve as a guide for the design of such systems.

Source: “Regenerative cooling using elastocaloric rubber: Analytical model and experiments,” by Gael Sebald, Atsuki Komiya, Jacques Jay, Gildas Coativy, and Laurent Lebrun, Journal of Applied Physics (2020). The article can be accessed at https://doi.org/10.1063/1.5132361 .