Abstract
The heat loss of room air under air conditioning is dominated by convective heat transfer on wall surfaces. Correct understanding of the thermal environment distribution in computational fluid dynamics (CFD) analysis therefore requires prediction of convective heat transfer on wall surfaces with excellent accuracy. It is necessary that a turbulence model and boundary conditions be chosen for CFD analysis that provide accurate understanding of a convective heat transfer behavior and laminarization phenomena of turbulence. The standard k-ε model for a fully disordered flow field cannot provide a highly accurate solution in viscous regions or regions where near-wall turbulence laminarizes. Accordingly, many low-Re turbulence models that can express convective heat transfer from laminar to turbulence exactly have been proposed; examples of their application to practical use computations are increasingly reported. However, because analytic accuracy in analysis using low-Re turbulence models might depend on grid division of a viscous sub layer region, verification of the accuracy has persisted as a problem. Detailed results of natural convection field experiment for CFD accuracy verification by Tian et al demonstrated the feasibility and validity of analysis using CFD for this issue. This study is intended to elucidate the analytic accuracy of CFD analysis of a natural convection field. Using various turbulence models, CFD analysis of the natural convection field experiment of Tian et al. was conducted. Comparison of analysis results with results of experiments verified that a low-Re k-εmodel and the SGS damping LES can reproduce natural convection heat transfer with sufficient accuracy.
