DNS of Conjugate Heat Transfer Phenomena With an Improved IB Method

In the present study, the immersed boundary (IB) method is applied as a tool to solve a conjugate heat transfer problem in a turbulent flow around a circular cylinder. This problem involves complexities such as transition, turbulent natural convection, and interaction of fluid convection and solid conduction. In order to enforce the velocity boundary condition at the IB, a second-order reconstruction method is employed. In order to handle coupling of the temperature field between different materials, the fluid-solid interface is approximated as a group of adjoining Cartesian faces from heterogeneous material regions. A Hermite-type interpolation is applied to reconstruct the temperature field across the fluid-solid interface with a reduced error. This approach has been verified with a heat transfer problem with an analytic solution and shows an improved result compared to the previous method. For the turbulent conjugate heat transfer problem around a circular cylinder, the predicted local Nusselt number shows a good agreement with the previous experiment. The statistical data obtained from this simulation can be used for turbulence modeling of heat transfer problems around a bluff body.