Paper 3: Volume 4 No.2 September 2005 Edition
Numerical
Study of Cross-Ventilation Using Two-Equation RANS Turbulence Models
Cheng-Hu
Hu1, Takashi Kurabuchi2, Masaaki Ohba1
1Dept.
Arch Eng., Faculty of Eng., Tokyo Polytechnic Univ, 1583 Iiyama Atsugi-shi, Kanagawa Prefecture, Japan
2Dept.
Arch, Faculty of Eng., Tokyo University of Science, Kagura-zaka 1-3,
Shijuku-ku,
Tokyo
162-0825,
Japan
Abstract
Cross-ventilation is a
mechanism using the pressure difference between the outdoor environment
and indoor space to provide an energy-saving method for ventilation
design. Since the ventilating flow in the vicinity of the opening is
highly turbulent and unsteady, the ideal numerical method to resolve the
structure of the ventilating flow is by using a time-dependent approach
such as large eddy simulation (LES). However, LES requires large computing
resources and there are also some uncertainties associated with the
discretisation of time scales and length scales of turbulence. Therefore,
an alternative has been sought. This study compared the flow simulations
computed by the standard k-e,
RNG k-e,
standard k-w
and SST k-w
models as well as LES and all the results were compared with experimental
measurement data. The main findings concluded that the SST k-w
model was able to depict the flow features satisfactorily and that the
calculation of flow rate was also accurate under various wind directions.
Key words: Cross-ventilation,
CFD, RANS turbulence model, measurement comparisons
References
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
.
Cebeci T and Smith AMO:
(1974) “Analysis of turbulent boundary layers”, ch 5. Academic press,
USA
.
Fluent Inc: (2003)
“Fluent User’s Guide”,
USA
.
Heiselberg P: (2004)
“Natural Ventilation Design”. The International Journal of
Ventilation, 2 (4), pp295-312.
Kurabuchi T, Ohba M,
Arashiguchi A, and Iwabuchi T: (2000) “Numerical study of airflow
structure of a cross-ventilated model building”. Air Distribution in
Rooms: Ventilation for Health and Sustainable Building,. 1,
pp313-318.
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, Ohba M and
Endo T: (2005) “Verification and streamtube analysis of simulated
results of airflow of a cross-ventilated building for various wind
incident angles: Part 2 – analysis of airflow of cross-ventilated
buildings based on LES and wind tunnel experiment”. J. Environ. Eng.
Architectural Institute of Japan, 591, pp7-13 (in Japanese).
Launder BE and Spalding
DB: (1972) “Lectures in Mathematical Models of Turbulence”. Academic
Press,
London
,
England
.
Menter FR: (1994)
“Two-equation eddy-viscosity turbulence models for engineering
applications”. AIAA Journal, 32, (8), pp1598-1605.
Ohba M: (2004) “Project
II: Natural Ventilation”. In: proceedings of ISWE1 – the first
international symposium on wind effects on buildings and urban environment,
Tokyo
, 8-9 March, 2004.
Vandoormaal JP and Raithby
GD: (1984) “Enhancements of the SIMPLE method for predicting
incompressible fluid flows”. Numer. Heat Transfer, 7,
pp147-163.
Wilcox
DC
: (1998) “Turbulence Modelling for CFD”. DCW Industries, Inc., La
Canada
,
California
.
Yakhot V and Orszag SA:
(1986) “Renormalization Group Analysis of Turbulence:
I.
Basic Theory”. Journal of Scientific Computing, 1, (1),
pp1-51.
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IJV Volume 4 No 2
Contents
Paper
1: POWBAM0
Paper
2: Inlet Conditions
Paper
3: RANS Model
Paper
4: Functional Availability
Paper
5: Probability Design
Paper
6: Ventilation Performance
Paper
7: Air Movement
Paper
8: Zonal Modelling
|
