Paper 3: Volume 5 No.3 Dec 2006 Edition
Applying the Local Dynamic
Similarity Model and CFD for the Study of Cross-Ventilation
Cheng-Hu
Hu1, Takashi Kurabuchi2 and Masaaki Ohba1
1Tokyo
Polytechnic University
,
Japan
2Tokyo
University of Science
,
Japan
Abstract
The Local Dynamic
Similarity Model (LDSM) is a ventilation model for predicting the
discharge coefficient and the inflow angle at the opening of a
cross-ventilated building. This model requires a dynamic pressure
generated by the wind velocity component tangential to the opening in
addition to wind pressure. Also, total pressure, wind pressure, static
pressure, room pressure and inflow velocity components are needed for
model validation. Under cross-ventilation, it is rather difficult to
measure these parameters, especially the total pressure and the velocity
components at the opening, as the inflow angle is not known a priori.
Therefore, an alternative was sought. This study applied a CFD method to
determine the required parameters as a way of using the local dynamic
similarity model. The CFD method had been validated with experimental
results before the CFD data was used for LDSM. Good agreement was obtained
between CFD and LDSM. Consequently the LDSM was also verified by CFD and
it was viable to combine LDSM and CFD for the study of cross-ventilation.
Key words: local dynamic
similarity model, cross-ventilation, CFD, SST k-w
model, opening position.
References
Awbi H: (2003).
“Ventilation of buildings” 2nd Ed., Spon Press,
London
, Chapter 3.
Barth TJ and Jespersen D:
(1989) “The design and application of upwind schemes on unstructured
meshes”. Technical Report AIAA-89-0366, AIAA 27th Aerospace Sciences
Meeting,
Reno
,
Nevada
.
Etheridge D: (2004).
“Natural ventilation through large openings – measurements at model
scale and envelope flow theory”. The
International Journal of Ventilation, 2,
(4), pp325-342.
Etheridge D and Sandberg
M: (1996). “Building ventilation – theory and measurement”. John
Wiley & Sons Ltd.,
England
. Chapter 3.
Fluent Inc.: (2003)
“Fluent User’s Guide”,
USA
.
Hu C-H, Kurabuchi T and
Ohba M: (2005). “Numerical study of cross-ventilation using two-equation
RANS turbulence models”. The
International Journal of Ventilation, 4,
(2), pp123-131.
Kurabuchi T, Ohba M, Endo
T, Akamine Y and Nakayama F: (2004). “Local dynamic similarity model of
cross-ventilation: Part 1 – Theoretical framework”. The
International Journal of Ventilation,
2, (4), pp371-382.
Kurabuchi T, Akamine Y, Ohba M, Endo T, Goto T, Kamata M: (2006). “A
study on the effects of porosity on discharge coefficient in
cross-ventilated buildings based on wind tunnel experiment”, The
International Journal of Ventilation, 5,
(1), pp67-78.
Menter FR: (1994).
“Two-equation eddy-viscosity turbulence models for engineering
applications”. AIAA Journal, 32, (8), pp1598-1605.
Ohba M, Irie K and
Kurabuchi T: (2001). “Study on airflow characteristics inside and
outside a cross-ventilation model, and ventilation flow rates using wind
tunnel experiments”. Journal of
Wind Engineering and Industrial Aerodynamics, 89,
pp1531-1524.
Ohba M, Kurabuchi T and
Irie K: (2002). “Experimental study on penetrating flow and pressure
loss through openings in a cross-ventilated model building”. J. Archit. Environ. Eng. AIJ, 522, pp21-27 (In Japanese).
Ohba M, Kurabuchi T, Endo
T, Akamine Y and Kamata M: (2004). “Evaluation of Prediction Accuracy by
Local Dynamic Similarity Model for Cross-Ventilation Flow Rate”. In: proceedings of ROOMVENT 2004, 9th International Conference on Air
Distribution in Rooms. Coimbra,
Portugal, 5 – 8 September, 2004.
Ohba M, Goto T, Kurabuchi T, Endo T and Akamine Y: (2006). “Experimental
Study on Predicting Wind-Driven Cross-Ventilation Flow Rates and Discharge
Coefficients Based on Local Dynamic Similarity Model”, The International Journal of Ventilation, 5, (1), pp105-114.
Vandoormaal JP and Raithby
GD: (1984) “Enhancements of the SIMPLE method for predicting
incompressible fluid flows”. Numer.
Heat Transfer, 7,
pp147-163.
|
Contents
Editorial
Ventilation
for Better Indoor Air Quality: Yuguo
Li
and Xianting
Li
Paper 1
Ventilation
for Better Indoor Air Quality: Yuguo
Li
and Xianting
Li
Paper
2
Performance
of Underfloor Air Distribution in a Field Setting: Fisk, W. J., Faulkner,
D., Sullivan, D. P., Chao, C., Wan, M. P., Zagreus, L. and Webster, T.
Paper 3
Applying
the Local Dynamic Similarity Model and CFD for the Study of
Cross-Ventilation: Hu, C-H.,
Kurabuchi, T. and Ohba, M.
Paper
4
Levels
of Indoor Airborne Microbes Associated with Ventilation Efficiency in
Naturally-Ventilated Residences: Su, H. J., Wu, P. C. and Chien, H. P.
Paper 5
Air
Quality and Thermal Comfort in an Office with Underfloor, Mixing and
Displacement Ventilation:
Cermak, R. and Melikov, A. K.
Paper
6
Passive
Tracer Gas Measurement of the Long Term Variation of Ventilation in Three
Swedish Dwellings: Stymne, H., Emenius, G. and Boman, C. A.
Paper
7
Validation
of a CFD Model for Research into Stratum Ventilation: Lin,
Z., Chow, T. T. and Tsang, C.F.
|
