Accommodating Volume Expansion Effects During Solid–Liquid Phase Change—A Comparative Study

The electronic components, instruments, sensors, and other satellite payload subsystems generate significant heat during repeated transient duty cycles. The thermal management of such satellite payload subsystems becomes more challenging under the influence of the microgravity environment. The rapid temperature fluctuations caused due to stringent space environment may lead to the overheating/failure of electronic devices. The phase change materials (PCM) are the natural fit for the thermal control of such satellite subsystems where the heat dissipation is non-continuous. Moreover, during the melting and solidification processes, the PCMs have a tendency to either expand or contract. Designing the containment system for PCM must take both thermal and structural factors into account. Due to the harsh environmental conditions, designing the containment system to accommodate PCM volume change, particularly for space applications, provides extra challenges. Consequently, the present work deliberates two different mass accommodation methods (i.e., an open boundary and a free/movable surface), which takes into account the effect of volume expansion on the melting cycle of PCM. The computational domain consists of an enclosure filled with paraffin-based PCM, and a comprehensive comparative analysis of the PCM melting accommodating volume expansion effects is discussed in the present work.