Entropy-Based Loss Coefficients for Turbulent Channel Flow With Heat Transfer

This paper presents a new entropy-based metric for local loss coefficients in turbulent flows with heat transfer. Unlike conventional methods of global loss characterization, such as a single valve loss coefficient, this paper examines an entropy-based alternative that tracks local variations of the loss coefficient. The local distribution of entropy production can provide useful information regarding the spatial distribution of mechanical energy losses, which can be then used to systematically optimize thermofluid systems. An application involving turbulent channel flow is specifically investigated. The friction factor is represented in terms of the local entropy production rates. By successfully predicting the local flow irreversibilities with this approach, re-design efforts can be more effectively focused on specific regions of highest entropy production.