Analyzing grid independency and numerical viscosity of computational fluid dynamics for indoor environment applications

作者：Wang Haidong; Zhai Zhiqiang^*

来源：Building and Environment, 2012, 52: 107-118.

DOI：10.1016/j.buildenv.2011.12.019

• Grid-independent
• Numerical viscosity
• Computational fluid dynamics
• Indoor environment

Computational fluid dynamics (CFD) has been introduced to indoor environment study for decades. Analysis of CFD results will first require the reach of a grid-independent CFD solution to eliminate the false information induced by numerical causes, e.g., grid and numerical scheme. judging a grid-independent solution has been mostly experience-based, leading the necessity of developing an objective and easy-to-use criterion for grid independency evaluation. This paper presents a new approach to assessing the grid independency of CFD modeling for indoor environment applications. A normalized root mean square error (RMSE) index is developed from the grid convergence index (GCI) concept in literature to evaluate the overall differences of predicted results with varying grid resolutions. The paper further introduces the use of numerical viscosity analysis method to verify the grid-independent solution of a CFD analysis, which also provides fundamental insight into the grid-induced error in numerical solutions. Although initially developed for indoor environment applications, the proposed RMSE index along with the numerical viscosity analysis method can be applied to most general CFD studies and has great potential of being incorporated into commercial CFD software to provide user a more accurate and objective alternative of checking grid independency of CFD simulation.

• 出版日期2012-6