Conjugate conduction /natural convection heat transfer in a simulated two-dimensional room-and floor heating system

Abstract

The purpose of this study is to provide a basic understanding to the problem of room heating by warm-water pipe circuits embedded in a floor slab. For a model floor which contains a row of parallel isothermal circular heating pipes, a conjugate conduction-natural convection heat transfer has been solved by numerical methods. The temperature distribution on the solid-fluid contact surface needed as a boundary condition is not known a priori, but can be determined iteratively by imposing a condition of continuity in local heat flux across the surface. In the convection space, coordinate stretching is used to bring the far-boundary into the computational domain, where a finite difference method is applied to solve the governing Boussinesq equations. On the other hand, in the conduction region the boundary integral equation method has been used to treat the irregular domain configuration in a relatively simple manner. The temperature distribution along, and local and overall rate of heat transfer crossing the solid-fluid interface were obtained. Isothermal contours both in the air and in the slab, and streamlines in the air have been also determined.