(417e) Convective Heat Transfer in Turbulent Flows

A generalized approach for predicting turbulent convective heat transfer coefficients using large eddy simulation is presented. This model is based on semi-empirical transport theory, which links the local convective heat transfer rate to the local energy dissipation rate within the near-wall boundary layer. We apply these approaches to agitated tanks over a range of operating conditions and impeller types, as well as pipe flow systems, cylinders in crossflow, and tube bundles. We validate the generality and reliability of the theoretical models against expectations from experimentally derived empirical design correlations.

The findings from this investigation present thee key implications: first, as a complement to physical testing, this modeling approach can be used to reliably predict local and overall heat transfer rates in agitated/turbulent systems using first-principles simulations. Second, because the approach appeals directly to the Navier-Stokes equations, it provides mechanistic insight into the link between operating conditions, fluid flow, and thermal convection. Third, because heat transfer is modeled in tandem and on-the-fly with the underlying fluid dynamics, the combined effects of convection and advection and be investigated directly, in terms of temperature dependent viscosities and reaction rates. In this sense, the approach can be used to perform first principles multi-physics simulation that make a priori predictions of convective heat transfer rates and thermal transport in turbulent flows.

A general approach for predicting convective heat transfer coefficients in turbulent systems, International Journal of Heat and Mass Transfer 220(24):124989