Numerical Investigation of the Effect of Angle Between Angularly Positioned Two Buildings on Velocity and Pressure Distribution

Yıl 2022, Cilt: 25 Sayı: 1, 361 - 371, 01.03.2022

Tekmile Cürebal , Yücel Özmen

https://doi.org/10.2339/politeknik.674761

Öz

In this study, a three-dimensional numerical solution of the flow fields around two angularly positioned building models is realized. In the solutions, Standard k-ɛ, RNG k-ɛ, Realizable k-ɛ and Standard k-ω turbulence models were used comparatively and the performances of turbulence models were investigated for flow around two angularly positioned building models. The performances of turbulence models were examined and when compared with experimental data, it is seen that the results obtained by using the Standard k-ɛ turbulence model has more compatible with the experimental data. For different building angles, the velocity and pressure distributions in the entire flow fields were examined at the Reynolds number 7,7x105 in detail. In the diverging passages, the K values obtained along the center line of the passage between the buildings were obtained much greater than the K values in the converging passages. When the effect of angular change on the pressure coefficient distributions on the surface of building models is examined for the 8 different building configurations where the angle between buildings varies between 0° -180°, it has been seen that the most critical negative pressure coefficient values are affected by the change in angle between the buildings in the diverging and converging building configurations.

Anahtar Kelimeler

Building aerodynamics, computational fluid dynamics, turbulent flow, turbulence model

Açılı Konumlandırılmış İki Bina Arasındaki Açının Hız ve Basınç Dağılımı Üzerine Etkisinin Sayısal İncelenmesi

Öz

Bu çalışmada, açılı konumlandırılmış iki bina modeli etrafındaki akış alanlarının üç boyutlu sayısal çözümü gerçekleştirilmiştir. Çözümlerde Standard k-ɛ, RNG k-ɛ, Realizable k-ɛ ve Standard k-ω türbülans modelleri karşılaştırmalı olarak kullanılmış ve açılı konumlandırılmış bina modelleri etrafındaki akış için türbülans modellerinin duyarlılıkları araştırılmıştır. Türbülans modellerinin deneysel veriler karşısındaki duyarlılıkları incelendiğinde, Standard k-ε türbülans modelinin kullanılmasıyla elde dilen sonuçların, deneysel verilerle daha uyumlu olduğu görülmüştür. Farklı bina açıları için gerçekleştirilen bu çalışmada, akış alanının tamamına ait hız ve basınç dağılımları Reynolds sayısının 7,7x105 değeri için ayrıntılı olarak incelenmiştir. Genişleyen geçitlerde, binalar arasındaki geçidin merkezi çizgisi boyunca elde edilen K değerleri, daralan geçitlerdeki K değerlerinden çok daha büyük olarak elde edilmiştir. Binalar arasındaki açının 0°-180° arasında değiştiği 8 farklı bina konfigürasyonu için, açısal değişimin bina modelleri yüzeyindeki basınç katsayısı dağılımlarına etkisi incelendiğinde, daralan ve genişleyen bina konfigürasyonlarında, en kritik negatif basınç katsayısı değerlerinin binalar arasındaki açının değişiminden etkilendiği görülmüştür.

Anahtar Kelimeler

Bina aerodinamiği, hesaplamalı akışkanlar dinamiği, türbülanslı akış, türbülans modeli

Kaynakça

• [1] Gandemer J., “Wind environment around buildings: Aerodynamics concepts”, Proc. of 4th Int. Conf. On Wind Effects on Buildings and Structures, Cambridge, 423-432, (1975).
• [2] Wiren B.G., “A wind tunnel study of wind velocities in passages between and through buildings”, Proc. of 4th Int. Conf. On Wind Effects on Buildings and Structures, Cambridge, 465-475, (1975).
• [3] Stathopoulos T. and Storms R., “Wind enviromental conditions in passages between buildings”, Journal of Wind Engineering and Industrial Aerodynamics, 24(1):19-31, (1986).
• [4] Blocken B., Carmeliet J.E., and Stathopoulos T., “CFD evaluation of wind speed conditions in passages between parallel buildings-Effect of wall-function roughness modifications for the atmospheric boundary layer flow”, Journal of Wind Engineering and Industrial Aerodynamics, 95: 941-962, (2007).
• [5] Tsang C.W., Kwok K.C.S., and Hitchcock P.A., “Wind tunnel study of pedestrian level wind enviromental around tall buildings: effects of building dimensions, seperation and podium”, Building and Environment, 49: 167-181, (2012).
• [6] Hong B. and Lin B., “Numerical studies of the outdoor wind environment and thermal comfort at pedestrian level in housing blocks with different building layout patterns and trees arrangement”, Renewable Energy, 73:18-27, (2015).
• [7] Blocken B., Stathopoulos T., and Carmeliet J.E., “Wind environmental conditions in passages between two long narrow perpendicular buildings”, Journal of Aerospace Engineering, 21(4):280-287, (2008(a)).
• [8] Blocken B., Moones P., Stathopoulos T. and Carmeliet J.E., “A numerical study on the existence of the venturi-effect in passages between perpendicular buildings”, Journal of Engineering Mechanics,134(12):1021-1028,(2008(b)).
• [9] Li B., Luo Z., Sandberg M. and Liu J., “Revisiting the ‘venturi effect’ in passage ventilation between two non-parallel buildings”, Building and Environment, 94:714-722, (2015).
• [10] Allegrini J. and Lopez B., “The influence of angular configuration of two buildings on the local wind climate”, Journal of Wind Engineering and Industrial Aerodynamics, 156:50-61, (2016).
• [11] Du Y., Mak C.M., Liu J., Xia Q., Niu J., and Kwok K.C.S.,“Effects of lift-up design on pedestrian level wind comfort in different building configuration under three wind direction”, Building and Environment, 117:84-99, (2017).
• [12] Liu J., Niu J., Mak C.M., and Xia Q., “Detached eddy simulation of pedestrian-level wind and gust around an elevated building”, Building and Environment, 125:168-179, (2017).
• [13] Du Y., Mak C.M. and, Ai Z.,“Detached eddy simulation of pedestrian-level wind and gust around an elevated building”, Environment Modelling & Software, 103:105-119, (2018).
• [14] Chew L.W. and Norford L.K,“Pedestrian-level wind speed enhancement in urban street canyons with void decks”, Building and Environment, 146:64-76, (2018).
• [15] Tominaga Y. and Stathopoulos T. “CFD modeling of pollution dispersion in a street canyon: Comparison between LES and RANS.”, Journal of Wind Engineering and Industrial Aerodynamics, 99:340-348, (2011).
• [16] Asfour O.S., “Prediction of wind environment in different grouping patterns of housing blocks”, Energy and Building, 42:2061-2069, (2010).
• [17] Ramponi R., Blocken B., de Coa L.B. and Janssen, W.D.,“CFD simulation of outdoor ventilation of generic urban configurations with different urban densities and equal and unequal street widths”, Building and Environment, 92:152-166, (2015).
• [18] Fan M., Chau C.K., Chan E.H.W. and Jia J., “A decision support tool for evaluating the air quality and wind comfort induced by different opening configurations for buildings in canyons”, Science of the Total Environment, 574:569-582, (2017).
• [19]Blocken B., Stathopoulos T. and van Beeck J.P.A.J., “Pedestrian-level wind conditions around buildings: review of wind-tunnel and CFD techniques and their accuracy for wind comfort assessment”, Building and Environment, 100:50-81, (2016).
• [20] Blocken B. and Stathopoulos T., “CFD simulation of pedestrian-level wind conditions around buildings: past achievements and prospects”, Journal of Wind Engineering and Industrial Aerodynamics, 121:138-145, (2013).
• [21] Stathopoulos T., “Computational wind engineering: past achievements and future challenges”, Journal of Wind Engineering and Industrial Aerodynamics, 67–68:509-532, (1997).
• [22] Murakami S., Ooka R., Mochida A., Yoshida S. and Kim S. “CFD analysis of wind climate from human scale to urban scale”, Journal of Wind Engineering and Industrial Aerodynamics, 8:57-81, (1999).
• [23] Blocken B., “50 years of computational wind engineering: past, present and future”, Journal of Wind Engineering and Industrial Aerodynamics, 129:69-102, (2014).
• [24] Druenen T.van, Hoff T.van, Montazeri H. and Blocken B.,“CFD evaluation of building geometry modifications to reduce pedestrian-level wind speed”, Building and Environment, 163: 106293, (2019).
• [25] ANSYS Fluent 14 User Guide, ANSYS, Inc, (2013).
• [26] Blocken B., “Computational Fluid Dynamics for urban physics: Importance, scales, possibilities, limitations and ten tips and tricks towards accurate and reliable simulations”, Building and Environment, 91: 219-245. (2015).
• [27] Launder B.E. and Spalding D.B. “The numerical computation of turbulent flows”, Computer Methods in Applied Mechanincs and Engineering, 3:269-289, (1974).
• [28] Shih, T.H., Liou, W.W., Shabbir, and Zhu, J. “A New k‐ε eddy‐viscosity model for high reynolds number turbulent flows–model development and validation”, Computers Fluids, 24:227-238, (1995).
• [29] Özmen, Y., Kaydok, T., “Kare kesitli bir yüksek bina üzerindeki türbülanslı akışın sayısal olarak incelenmesi”, KSU Mühendislik Bilimleri Dergisi, 17(2):15-25, (2014).
• [30] Kolmogorov A.N., “Equations of turbulent motion of an incompressible fluid”, Izv Acad. Sci. USSR Phys., 6:56–58, (1942).
• [31] Franke J., “Recommendations of the COST Action C14 on The Use of CFD in Predicting Pedestrian Wind Environment”, The Fourth International Symposium on Computational Wind Engineering, Yokohama, (2006).
• [32] Lawson T.V., “Wind effects on buildings, Vol. 1”, Applied Science Publishers Ltd., London, England, (1980).
• [33] Dutt A.J., “Wind flow in an urban environment” Environmental Monitoring and Assessment, 19(1-3), 495-506, (1991).
• [34] Blocken B. and Carmeliet J., “Pedestrian Wind Environment around Buildings:Literature Review and Practical”, Journal of Thermal Envelope and Building Science, 28(2):107-159,(2004).
• [35] Venturi G.B., “Experimental enquiries concerning the principle of the lateral communication of motion in fluids: applied to the explanation of various hydraulic phenomena”, Translated from the French by Nicholson W, 1st English ed., J. Taylor, Architectural Library, High-Holborn, London, (1799).