Space- and time-resolved interferometric measurements of the thermal boundary layer at a periodically magnetized gadolinium plate

作者：Lei Z; Yang X; Haberstroh Ch; Pulko B; Odenbach S; Eckert K^*

来源：International Journal of Refrigeration, 2015, 56: 246-255.

DOI：10.1016/j.ijrefrig.2015.01.004

• Magnetic cooling
• Gadolinium
• Mach-Zehnder interferometer
• Parallel-plate magnetic regenerator

By means of a Mach-Zehnder interferometer we examine the transient dynamics of heat transfer from two periodically magnetized gadolinium (Gd) plates into a heat transfer fluid (n-decane). We demonstrate that the propagation of the thermal fronts emanating from the Gd plates after magnetization or demagnetization obeys a root t-dependence. A finite time required for magnetization and demagnetization causes a spatially delayed propagation of the thermal fronts. The diffusive heat flux, derived from the temperature profiles, experiences a drop down by about 80% after first 3 s while the percentage of thermal energy transferred into n-decane experiences a maximum there. Although limited to heat transfer into a stagnant fluid, the present works provides reasons for lower bounds of geometry and operation frequency of a simplified parallel-plate structure in the diffusive limit. In this way, the results are instructive for an efficient design of a parallel-plate magnetic regenerator with forced convection.

• 出版日期2015-8