Heptane slick pool fires on water with inserted high-temperature heat pipes

The coupled heat transfer and combustion dynamics of floating fuel slicks play a critical role in governing flame behavior and burning characteristics. This study investigates the use of vertically inserted high-temperature heat pipes (HTHPs) at the burning surface of a 10 mm thick floating n-heptane slick. HTHPs (150 mm length, 30 mm diameter) with liquid metal working fluid are investigated under varying number ( = 1, 2, 3) and immersion depths ( = 5–20 mm). Experimental analysis quantifies the dominant thermal pathways, including radiation, nucleate boiling, and conduction at key interfaces of the pool surface, the HTHP immersed wall, and the fuel/water interface. Flame height increases with the number of HTHPs but decreases with greater immersion depth, peaking at 90 cm for = 3 at = 5 mm, which is a 44.3% rise over baseline. The HTHP evaporator reaches isothermal temperatures of 400–550 °C, enabling effective vapor transport, while the bottom immersed section remains below the vapor flow transition temperature (181 °C) when immersed at 5–10 mm. Radiative heat fluxes from both the flame and the HTHP wall increase with while nucleate boiling is enhanced by increasing the heat pipe wall exposure. An energy-based mass loss model efficiently captures experimental trends and reflects dynamic burning configurations. These findings demonstrate that phase change-driven heat transfer devices can modify the thermal feedback in n-heptane slick burning, providing mechanistic insights into heptane slick pool fire combustion with thermally conductive devices.