Numerical Simulation of Transient Thermal Transport on a Rotating Disk Under Partially Confined Laminar Liquid Jet Impingement

This paper considers the transient conjugate heat transfer characterization of a partially confined liquid jet impinging on a rotating and uniformly heated solid disk of finite thickness and radius. A constant heat flux was imposed at the bottom surface of the solid disk at $t=0$⁠, and heat transfer was monitored for the entire duration of the transient until the steady state condition was reached. Calculations were done for a number of disk materials using water as the coolant, covering a range of Reynolds numbers (225–900), Ekman numbers $(7.08×10−5−∞)$⁠, nozzle-to-target spacing $(β=0.25–1.0)$⁠, confinement ratios $(rp/rd=0.2–0.75)$⁠, disk thicknesses to nozzle diameter ratios $(b/dn=0.25–1.67)$⁠, and solid to fluid thermal conductivity ratios (36.91–697.56). It was found that a higher Reynolds number decreases the time to achieve the steady state condition and increases the local and average Nusselt number. The duration of the transient increases with the increment of the Ekman number and disk thickness, and the reduction in the thermal diffusivity of the disk material.