A two-zone model for natural cross-ventilation

Cross-ventilation flows (CV) are characterized by significant inflow momentum conservation as fluid flows across an enclosed rectangular volume as a confined jet. When the inflow area is smaller than the volume cross-sectional area the CV flow has distinct jet and recirculation flow regions. The simplified model presented in this paper characterizes the CV flow as the result of a confined axisymmetric jet driving one or two recirculation regions, each of which is a lid-driven cavity flow. The model consists of calibrated analytical scaling laws that predict characteristic velocities in the jet and recirculation flow regions using as inputs the inflow velocity, and relevant geometry parameters. The proposed model can deal with impinging flow angle effects and multiple inflow opening configurations. Comparison between the model predictions and validated computational fluid dynamics (CFD) simulations show adequate agreement for simplified prediction of characteristic flow velocities in cross-ventilated spaces.

[1]  Maria K. Koukou,et al.  Natural cross-ventilation in buildings: Building-scale experiments, numerical simulation and thermal comfort evaluation , 2008 .

[2]  Jiun-Jih Miau,et al.  Flow visualization, PIV measurement and CFD calculation for fluid-driven natural cross-ventilation in a scale model , 2013 .

[3]  Liang Ji,et al.  WIND TUNNEL INVESTIGATION ON INFLUENCE OF FLUCTUATING WIND DIRECTION ON CROSS NATURAL VENTILATION , 2011 .

[4]  H. C. Hottel,et al.  Mixing and flow in ducted turbulent jets , 1963 .

[5]  Bert Blocken,et al.  CFD analysis of cross-ventilation of a generic isolated building with asymmetric opening positions : impact of roof angle and opening location , 2015 .

[6]  Guilherme Carrilho da Graça,et al.  Simplified models for heat transfer in rooms , 2003 .

[7]  Edward Arens,et al.  The prediction of indoor air motion for occupant cooling in naturally ventilated buildings , 1991 .

[8]  Maurel,et al.  Experimental study of self-sustained oscillations in a confined jet. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[9]  Konstantinos-Stefanos Nikas,et al.  Experimental and numerical investigation of the tracer gas methodology in the case of a naturally cross-ventilated building , 2012 .

[10]  Ashwin W. Patwardhan,et al.  Characteristics of turbulent confined jets , 2008 .

[11]  H. Awbi.  Ventilation of buildings , 1873 .

[12]  D. Grawe,et al.  BEST PRACTICE GUIDELINE FOR THE CFD SIMULATION OF FLOWS IN THE URBAN ENVIRONMENT , 2007 .

[13]  R. Curtet,et al.  Confined jets and recirculation phenomena with cold air , 1958 .

[14]  J. Koseff,et al.  Reynolds number and end‐wall effects on a lid‐driven cavity flow , 1989 .

[15]  Qingyan Chen.  COMPARISON OF DIFFERENT k-ε MODELS FOR INDOOR AIR FLOW COMPUTATIONS , 1995 .

[16]  Andreas K. Athienitis,et al.  Airflow assessment in cross-ventilated buildings with operable façade elements , 2011 .

[17]  Jan Carmeliet,et al.  PIV measurements and analysis of transitional flow in a reduced- scale model: ventilation by a free plane jet with Coanda effect , 2012 .

[18]  M. D. Deshpande,et al.  FLUID MECHANICS IN THE DRIVEN CAVITY , 2000 .

[19]  Joseph C. S. Lai,et al.  Two parallel plane jets: Comparison of the performance of three turbulence models , 1998 .

[20]  PF Linden,et al.  Design and testing of a control strategy for a large , 2 naturally ventilated office building 3 , 2004 .

[21]  Hao Liu,et al.  Velocity measurements within confined turbulent jets: Application to cardiovalvular regurgitation , 1997 .

[22]  F. P. Ricou,et al.  Measurements of entrainment by axisymmetrical turbulent jets , 1961, Journal of Fluid Mechanics.

[23]  G. Evola,et al.  Computational analysis of wind driven natural ventilation in buildings , 2006 .

[24]  Edward Arens,et al.  Natural Ventilation for Energy Savings in California Commercial Buildings , 2016 .

[25]  Nigel B. Kaye,et al.  CFD Study of Merging Turbulent Plane Jets , 2011 .

[26]  van Taj Twan Hooff,et al.  On the suitability of steady RANS CFD for forced mixing ventilation at transitional slot Reynolds numbers. , 2013, Indoor air.

[27]  N. Rajaratnam,et al.  Three-Dimensional Turbulent Wall Jets , 1974 .

[28]  Chia-Ren Chu,et al.  Wind-driven cross ventilation in long buildings , 2014 .

[29]  Peter V. Nielsen,et al.  Specification of a Two-Dimensional Test Case: (IEA) , 1990 .

[30]  An-Shik Yang,et al.  Myth of ecological architecture designs: Comparison between design concept and computational analysis results of natural-ventilation for Tjibaou Cultural Center in New Caledonia , 2011 .

[31]  Bje Bert Blocken,et al.  CFD simulation of cross-ventilation for a generic isolated building : impact of computational parameters , 2012 .

[32]  Moncef Krarti,et al.  Assessment of natural and hybrid ventilation models in whole-building energy simulations , 2011 .

[33]  Atila Novoselac,et al.  Cross ventilation with small openings: Measurements in a multi-zone test building , 2012 .