Dynamic CFD Modelling of Thermal Mass and Air Movement

Abstract Recent work has begun to consider the potential for using freeze flow techniques in Computational Fluid Dynamics programs for carrying out long term simulations of time dependent flows. This paper describes and tests a new, adaptive control method which automatically adjusts the lengths of the frozen and unfrozen flow periods in the solution procedure, based on current and imminent conditions. The adaptive control method demonstrates improved performance compared with an invariable control method. Tests using the new method for different flow scenarios have shown good agreement with the results obtained using a traditional fully transient CFD simulation in which all equations are solved without interruption. Simulation CPU time and data storage requirements were reduced by up to 88% and 70% respectively when compared with a fully transient CFD simulation.

[1]  Maria Kolokotroni,et al.  Transient Solution Methods for Dynamic Thermal Modelling within CFD , 2002 .

[2]  Simon J. Rees,et al.  Simulation of steady-state natural convection using CFD , 2005 .

[3]  D. Wilcox.  Turbulence modeling for CFD , 1993 .

[4]  Maria Kolokotroni,et al.  Dynamic thermal CFD simulation of a typical office by efficient transient solution methods , 2005 .

[5]  Jon Hand,et al.  CONTRASTING THE CAPABILITIES OF BUILDING ENERGY PERFORMANCE SIMULATION PROGRAMS , 2008 .

[6]  Baruch Givoni,et al.  Effectiveness of mass and night ventilation in lowering the indoor daytime temperatures. Part I: 1993 experimental periods , 1998 .

[7]  Cezar O.R. Negrão,et al.  CONFLATION OF COMPUTATIONAL FLUID DYNAMICS AND BUILDING THERMAL SIMULATION , 1995 .

[8]  V. Geros,et al.  Experimental evaluation of night ventilation phenomena , 1999 .

[9]  S. Koga,et al.  Computer effort saving methods in unsteady calculations of room airflows and thermal environments , 1998 .

[10]  Malcolm J. Cook,et al.  Simulation dynamisch‐thermischen Langzeitverhaltens in Gebäuden mittels CFD , 2006 .

[11]  J. Rincón,et al.  Experimental and numerical evaluation of a solar passive cooling system under hot and humid climatic conditions , 2001 .

[12]  Qingyan Chen,et al.  STRATEGIES FOR COUPLING ENERGY SIMULATION AND COMPUTATIONAL FLUID DYNAMICS PROGRAMS , 2001 .

[13]  Francis Allard,et al.  Night ventilation for building cooling in summer , 1997 .

[14]  Zhiqiang John Zhai,et al.  Performance of coupled building energy and CFD simulations , 2005 .

[15]  Maria Kolokotroni,et al.  Cooling-energy reduction in air-conditioned offices by using night ventilation , 1999 .