Theoretical and Experimental Study of Close-contact Melting for Power-law Fluids Under Convective Effects
Article
Hu, N, Xu, Z, Li, Z et al. (2023). Theoretical and Experimental Study of Close-contact Melting for Power-law Fluids Under Convective Effects
. 44(1), 162-170.
Hu, N, Xu, Z, Li, Z et al. (2023). Theoretical and Experimental Study of Close-contact Melting for Power-law Fluids Under Convective Effects
. 44(1), 162-170.
Close-contact melting (CCM) is a form of solid-liquid phase change with high heat transfer rate, but the existing studies usually assume that the phase change materials (PCM) are Newtonian fluids and that the convective effects within the molten thin liquid film are neglected. In this paper, a theoretical CCM model for typical non-Newtonian fluids under convective effects is developed based on the power-law rheological model and the scaling analysis. The instantaneous melting rate and the thickness of the thin liquid film are measured using the photo-based recording method and the laser interference method, respectively. The results show that the model can accurately predict the melting rate and liquid film thickness during the CCM of power-law fluid, and the convective effect in the liquid film will reduce the heat flux at the solid-liquid phase interface, leading to a slower melting rate. The convection in the liquid film is influenced by the Stephan number, power-law coefficient C and exponent n, which are independent of the aspect ratio and solid-liquid density ratio of the PCM. Decreasing the power-law coefficient C and exponent n accelerates the melting process, and the thickness of the liquid film at the end of melting depends on the power-law coefficient C.
