  This study experimentally investigated the influence of heat transfer from a
heated hydrofoil on cavitating flow to understand the evaporation phenomenon
under high-heat-flux and high-speed conditions. A temperature difference was
generated between the hydrofoil and mainstream by installing an aluminum
nitride heater in a NACA0015 hydrofoil fabricated from copper. A cavitation
experiment was performed in a high-temperature water cavitation tunnel at the
Institute of Fluid Science, Tohoku University. The effect of heating on
cavitating flow was evaluated by changing the mainstream velocity and pressure,
namely the cavitation number, at a fixed heater power of 860 W. Results showed
that the heat transfer from the hydrofoil affected cavitating flow in terms of
the cavity length, cavity aspect, and periodicity. The effect on the cavity
length became stronger at a lower velocity owing to a higher hydrofoil
temperature. The variation in periodicity implied that the heating effect
reduced the unsteadiness of cavitation. A modified cavitation number was
proposed by considering the heat transfer from the heated wall. A thermal
correction term was derived by considering that the fluid temperature close to
the heated hydrofoil was affected by the turbulent convective heat transfer
between the mainstream and hydrofoil. The corrected cavitation number can be
considered as a parameter that describes the cavity length in the isothermal
and heated cases in a unified expression.
