Advances in simulations of heat exchange in fluid flows by high-order methods

Abstract

The article presents high-order simulations of heat transfer in fluid flow. Heat induced changes in material properties (density, viscosity and heat conductivity) substantially influence flow structures. The change of fluid density implies naturally the thermal expansion what results in non-homogeneous divergence of velocity and the model of evolutionary Navier-Stokes-Fourier equations is not strictly incompressible in this case. Proposed algorithm treats the model as a fully coupled system of equations. Applied method of operator splitting is promissing to become a more general concept for numerical modelling of active quantities advected by incompressible fluids. This work follows the 2D results presented during EFM 2019 and extends to 3D together with advances of the code reimplementation to current version of the Nektar++ library (open-source framework for spectral/hp finite elements). Results for various settings for both the forced/mixed and natural convection are shown.