Pulsating heat pipes for sustainable energy systems: Application-specific evidence and conditional design considerations

Effective thermal management is essential to the efficiency, safety, and scalability of sustainable energy systems. Pulsating heat pipes (PHPs) offer compact, passive heat transport through self-excited two-phase motion in wickless channels. Although existing reviews have extensively addressed PHP mechanisms and performance, translating this knowledge into application-specific design guidance remains challenging. This review examines PHP developments across four major domains: space systems, cryogenic cooling, solar energy utilization, and terrestrial applications. It focuses on how thermal, spatial, mechanical, and safety requirements guide the selection of channel geometry, filling ratio, working fluid, and integration strategy. Application-specific design tables synthesize these relationships into practical guidance, specifying the relevant operating conditions and validation needs. The synthesis emphasizes that reliable performance requires coordinated parameter selection and source–sink matching, rather than isolated optimization of individual variables. Manufacturing feasibility, material compatibility, and environmental and economic considerations complement the thermal assessment by addressing practical implementation requirements. By linking physical understanding with application requirements, this review provides a basis for informed device selection and system integration, while identifying the reliability and validation gaps that must be addressed to advance PHPs as practical thermal management solutions for sustainable energy systems.