Heat transfer of a radially rotating furrowed channel with two opposite skewed sinusoidal wavy walls

An experimental study of heat transfer in a radially rotating furrowed channel with two opposite walls enhanced by skewed sinusoidal waves was performed to generate the full-field Nusselt number (Nu) data over two wavy walls. Although the static wavy channel has been proven as an effective heat transfer enhancement (HTE) measure, no previous study examined its heat transfer performances with rotation. As another first-time attempt for turbine cooling researches, the Nu scans over the entire rotational leading (stable) and trailing (unstable) walls were acquired using the infra-red thermography which proved highly advantageous due to its capability to examine the rotating buoyancy effects in details. A selection of experimental data illustrates the full-field Nu variations responding to the changes of Reynolds (Re), rotation (Ro) and buoyancy (Bu) numbers. Parametric analysis is subsequently followed to disclose the individual and interdependent Re, Ro and Bu effects on Nu in the attempt to derive the heat transfer correlations for the area-averaged Nu over the developed flow region (Nu¯FD) on the rotational leading and trailing wavy walls. Within the parametric ranges tested, the rotational leading and trailing Nu¯FD values respectively fall between 3.4-4.3 and 4.2-6.4 times of the Dittus-Boelter datum, which grant the potential applicability of wavy channel as a HTE measure for cooling of gas turbine rotor blades.