Wall Properties and Heat Transfer in Near-Wall Turbulent Flow

Direct numerical simulation of a passive scalar in fully developed turbulent channel flow is used to show that Nusselt number is not only a function of Reynolds and Prandtl number, but also depends on properties of a heating wall. Variable thickness of the heating wall and variable heater properties, combined in a fluid–solid thermal activity ratio , can change the Nusselt number of the turbulent channel flow for up to 1% at the same Reynolds and Prandtl number and at the same wall heat flux.