Numerical Investigation of Flow and Heat Transfer Performance of Nano-Encapsulated Phase Change Material Slurry in Microchannels

TLDR

Microchannels are employed in high‑heat‑generation applications, and PCM slurries enhance heat transfer by providing increased heat capacity during phase change. This study numerically evaluates the performance of a nano‑encapsulated PCM slurry in a manifold microchannel heat sink. The slurry is modeled as a bulk fluid with variable specific heat, and a fully three‑dimensional coupled temperature–velocity field is solved, incorporating fin/wall effects, axial conduction, and developing flow. Results show that particle concentration, inlet temperature, PCM melting range, and heat flux significantly influence heat transfer, and the nano‑encapsulated slurry outperforms a pure single‑phase fluid in the microchannel configuration.

Abstract

Microchannels are used in applications where large amount of heat is produced. Phase change material (PCM) slurries can be used as a heat transfer fluid in microchannels as they provide increased heat capacity during the melting of phase change material. For the present numerical investigation, performance of a nano-encapsulated phase change material slurry in a manifold microchannel heat sink was analyzed. The slurry was modeled as a bulk fluid with varying specific heat. The temperature field inside the channel wall is solved three dimensionally and is coupled with the three dimensional velocity and temperature fields of the fluid. The model includes the microchannel fin or wall effect, axial conduction along the length of the channel, developing flow of the fluid and not all these features were included in previous numerical investigations. Influence of parameters such as particle concentration, inlet temperature, melting range of the PCM, and heat flux is investigated, and the results are compared with the pure single phase fluid.