Commenced in January 2007
Paper Count: 30011
Characterisation of Wind-Driven Ventilation in Complex Terrain Conditions
Abstract:The physical effects of upstream flow obstructions such as vegetation on cross-ventilation phenomena of a building are important for issues such as indoor thermal comfort. Modelling such effects in Computational Fluid Dynamics simulations may also be challenging. The aim of this work is to establish the cross-ventilation jet behaviour in such complex terrain conditions as well as to provide guidelines on the implementation of CFD numerical simulations in order to model complex terrain features such as vegetation in an efficient manner. The methodology consists of onsite measurements on a test cell coupled with numerical simulations. It was found that the cross-ventilation flow is highly turbulent despite the very low velocities encountered internally within the test cells. While no direct measurement of the jet direction was made, the measurements indicate that flow tends to be reversed from the leeward to the windward side. Modelling such a phenomenon proves challenging and is strongly influenced by how vegetation is modelled. A solid vegetation tends to predict better the direction and magnitude of the flow than a porous vegetation approach. A simplified terrain model was also shown to provide good comparisons with observation. The findings have important implications on the study of cross-ventilation in complex terrain conditions since the flow direction does not remain trivial, as with the traditional isolated building case.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1316470Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF
 M. Shirzadi, M. Naghashzadegan, and P. A. Mirzaei, “Improving the CFD modelling of cross-ventilation in highly-packed urban areas,” Sustainable Cities and Society, vol. 37, pp. 451–465, 2018. (Online). Available: http://www.sciencedirect.com/science/article/pii/S2210670717312891.
 R. Ramponi and B. Blocken, “CFD simulation of cross-ventilation for a generic isolated building: Impact of computational parameters,” Building and Environment, vol. 53, pp. 34–48, jul 2012. (Online). Available: http://www.sciencedirect.com/science/article/pii/S0360132312000133.
 L. Wang and N. H. Wong, “Coupled simulations for naturally ventilated rooms between building simulation (BS) and computational fluid dynamics (CFD) for better prediction of indoor thermal environment,” Building and Environment, vol. 44, no. 1, pp. 95–112, jan 2009. (Online). Available: http://www.sciencedirect.com/science/article/pii/S0360132308000231.
 A. H. Abdullah and F. Wang, “Design and low energy ventilation solutions for atria in the tropics,” Sustainable Cities and Society, vol. 2, no. 1, pp. 8–28, 2012. (Online). Available: http://www.sciencedirect.com/science/article/pii/S2210670711000606.
 A. Mochida, H. Yoshino, S. Miyauchi, and T. Mitamura, “Total analysis of cooling effects of cross-ventilation affected by microclimate around a building,” Solar Energy, vol. 80, no. 4, pp. 371–382, 2006. (Online). Available: http://www.sciencedirect.com/science/article/pii/S0038092X05003075.
 X.-Y. Ma, Y. Peng, F.-Y. Zhao, C.-W. Liu, and S.-J. Mei, “Full Numerical Investigations on the Wind Driven Natural Ventilation: Cross Ventilation and Single-sided Ventilation,” Procedia Engineering, vol. 205, pp. 3797–3803, 2017. (Online). Available: http://www.sciencedirect.com/science/article/pii/S1877705817346842.
 H. Wang, P. Karava, and Q. Chen, “Development of simple semiempirical models for calculating airflow through hopper, awning, and casement windows for single-sided natural ventilation,” Energy and Buildings, vol. 96, pp. 373–384, 2015. (Online). Available: http://www.sciencedirect.com/science/article/pii/S0378778815002509.
 T. Clima, “Ultrasonic anemometer 3D operating instructions,” Tech. Rep., 2012. (Online). Available: http://www.novalynx.com/images/200-81000.jpg.
 W. Ltd., “www.windspeed.co.uk.” (Online). Available: www.windspeed.co.uk.
 T. van Hooff, B. Blocken, and Y. Tominaga, “On the accuracy of CFD simulations of cross-ventilation flows for a generic isolated building: Comparison of RANS, LES and experiments,” Building and Environment, vol. 114, pp. 148–165, 2016. (Online). Available: http://linkinghub.elsevier.com/retrieve/pii/S036013231630511X.
 D. Micallef, V. Buhagiar, and S. P. Borg, “Cross-ventilation of a room in a courtyard building,” Energy and Buildings, vol. 133, pp. 658–669, 2016. (Online). Available: http://linkinghub.elsevier.com/retrieve/pii/S0378778816309124.
 F. Jørgensen, “How to measure turbulence with hot-wire anemometersa practical guide,” Dantec Dynamics, p. 3244, 2002.
 I. Ansys, “ANSYS Fluent Theory Guide,” vol. 15317, no. November, p. 514, 2013.
 B. C. J¨org Franke, Antti Hellsten, Heinke Schl¨unzen, Best Practice Guideline for the Cfd Simulation of Flows in the Urban Environment Quality Assurance and Improvement of, 2007, no. May.
 Y. Tominaga, A. Mochida, R. Yoshie, H. Kataoka, T. Nozu, M. Yoshikawa, and T. Shirasawa, “AIJ guidelines for practical applications of CFD to pedestrian wind environment around buildings,” Journal of Wind Engineering and Industrial Aerodynamics, vol. 96, no. 10-11, pp. 1749–1761, oct 2008. (Online). Available: http://www.sciencedirect.com/science/article/pii/S0167610508000445.
 M. Ray, A. Rogers, and J. McGowan, “Analysis of Wind Shear Models and Trends in Different Terrains,” AWEA Wind Power 2005 Conference, no. June 2006, pp. 4–7, 2006.
 H. K. Versteeg and W. Malalasekera, An Introduction to Computational Fluid Dynamics: The Finite Volume Method. Pearson Education Limited, 2007. (Online). Available: http://books.google.com.mt/books?id=RvBZ-UMpGzIC.
 L. Manickathan, T. Defraeye, J. Allegrini, D. Derome, and J. Carmeliet, “Aerodynamic characterisation of model vegetation by wind tunnel experiments,” no. June, pp. 30–31, 2016.
 C. Gromke, “Modeling vegetation in Wind Engineering wind tunnel studies,” The Seventh International Colloquium on Bluff Body Aerodynamics and Applications, pp. 1421–1428, 2012.
 K. Grunert, F., Benndorf, D., Klingbeil, “Neuere Ergebnisse zum Aufbau von Schutzpflanzungen,” in Beitr¨age f¨ur die Forstwissenschaft 18, 1984, pp. 108–115.
 V. Yakhot, S. A. Orszag, S. Thangam, T. B. Gatski, and C. G. Speziale, “Development of turbulence models for shear flows by a double expansion technique,” Physics of Fluids A: Fluid Dynamics (1989-1993), vol. 4, no. 7, 1992.
 G. Evola and V. Popov, “Computational analysis of wind driven natural ventilation in buildings,” Energy and Buildings, vol. 38, no. 5, pp. 491–501, may 2006. (Online). Available: http://www.sciencedirect.com/science/article/pii/S0378778805001702.
 P. Karava, T. Stathopoulos, and A. K. Athienitis, “Airflow assessment in cross-ventilated buildings with operable fac¸ade elements,” Building and Environment, vol. 46, no. 1, pp. 266–279, 2011.
 B. A. Kader, “Temperature and concentration profiles in fully turbulent boundary layers,” International Journal of Heat and Mass Transfer, vol. 24, no. 9, pp. 1541–1544, 1981. (Online). Available: http://www.sciencedirect.com/science/article/pii/0017931081902209.
 H. C. CHEN and V. C. PATEL, “Near-wall turbulence models for complex flows including separation,” AIAA Journal, vol. 26, no. 6, pp. 641–648, jun 1988. (Online). Available: https://doi.org/10.2514/3.9948.
 M. Wolfshtein, “The velocity and temperature distribution in one-dimensional flow with turbulence augmentation and pressure gradient,” International Journal of Heat and Mass Transfer, vol. 12, no. 3, pp. 301–318, 1969. (Online). Available: http://www.sciencedirect.com/science/article/pii/001793106990012X.
 P. J. Roache, K. N. Ghia, and F. M. White, “Editorial Policy Statement on the Control of Numerical Accuracy,” Journal of Fluids Engineering, vol. 108, no. 1, p. 1, 1986.
 P. J. Roache, “Verification and Validation in Computational Science and Engineering.” Hermosa Publishers, 1998, pp. 107–141.