A numerical study of algebraic flux models for heat and mass transport simulation in complex flows

作者：Rossi Riccardo^*

来源：International Journal of Heat and Mass Transfer, 2010, 53(21-22): 4511-4524.

DOI：10.1016/j.ijheatmasstransfer.2010.06.042

• Scalar transport
• Complex flows
• RANS
• Eddy-diffusivity
• Algebraic flux models

A numerical study of heat and mass transport based on the Reynolds-Averaged Navier-Stokes and scalar transport equations is presented to establish the predictive capabilities of algebraic flux models compared to the standard eddy-diffusivity representation. The analysis of scalar transport in simple-shear flows is initially performed to provide a basic validation of numerical techniques and scalar flux closures. The evaluation of algebraic models is carried out by examining the flow and scalar transport phenomena over a wavy wall and comparing the results to reliable direct numerical simulations. Despite the similarities with the standard gradient-diffusion hypothesis and the questionable validity of local-equilibrium conditions, the results show that algebraic models provide an efficient way to improve heat and mass transport predictions in complex flows with respect to the standard eddy-diffusivity model. The impact of abandoning the isotropic eddy-diffusivity in favor of a tensorial representation is found particularly significant in the analysis of scalar dispersion from a point source over the wavy wall, where lateral transport comes into play. While it is found that algebraic closures also represent a reasonable approximation for the spanwise scalar flux, the lateral spread of scalar concentration is considerably under-estimated by the standard gradient-diffusion model.

• 出版日期2010-10