Sensitivity Analysis of Microencapsulated Phase Change Material (MEPCM) Slurry with Arbitrary Particle Shapes

The purpose of the study upon which this paper reports is to investigate the sensitivity of the microencapsulated phase change material (MEPCM) slurry model to different particle shapes. The MEPCM slurry flow investigated is fully-developed in a circular tube under laminar conditions with a constant wall temperature boundary condition. Four different particle shapes were chosen for the study, and a detailed analysis has been conducted on all of them. The main parameters investigated are the Reynolds number (Re), the Stefan number (Ste), the particle shape, the dimensionless particle area (A*), and the particle shape aspect ratio (AR). The aspect ratio is defined as the ratio of the horizontal and vertical distances of each shape. This parameter will be used to vary the shape by changing the dimensionless perimeter (P*) while keeping A* constant. A MATLAB code was developed to solve the resulting problem using the finite difference method. Results show that using different MEPCM particle shapes does in fact affect the average Nusselt number (Nuaν) of the MEPCM slurry. The Nuaν for the MEPCM particle was found to increase by up to 4.22% compared to that of the conventional circular particle shape. The dimensionless perimeter (P*) of the particle, on the other hand, was found to increase by up to 43.58% compared to the conventional circular particle. Results of the study highlight the importance of taking the MEPCM particle shape into account for more accurate modeling of the problem and hence be more pointed in identifying the parameters that can enhance heat transfer