Experimental investigation of a bio-based commercial phase change material melting in an inclined rectangular enclosure

The interest in phase change materials (PCMs) for various engineering applications such as thermal management or energy storage has grown in recent years. In response, many different materials have been identified as viable PCMs in the literature, along with a proliferation of commercially available products. This research presents material property characterization and experimental data for one such commercial bio-based PCM, utilizing established analytical instruments and a common heat transfer experiment typically employed for the validation of enthalpy-porosity models. Melting within a 50 mm $\times$ 50 mm $\times$ 120 mm rectangular container subjected to an isothermal boundary is observed across a range of angles, from 30$°$ to 90$°$ as measured from the horizontal. A discussion of melting regimes and natural convection within vertical and inclined melting phase change problems is provided, while key influences on performance are identified. The impact of the change in incline on melting time is documented, with the largest effect being a 35% increase in melting speed from 90° to 30° at 47 °$C$ and a 46% increase at 57 °$C$ This study provides new results regarding the interaction between wall temperature and inclination during melting in rectangular enclosures, along with comprehensive validation data for evaluating numerical modeling methods.