American Journal of Energy Engineering 2014; 2(1): 27-36 Published online February 28, 2014 (http://www.sciencepublishinggroup.com/j/ajee) doi: 10.11648/j.ajee.20140201.14 Survey of airflow around multiple buildings Ahmed A. Rizk 1, 2 , Gregor P. Henze 3 1 Architectural Engineering Department, Faculty of Engineering, University of Tanta, Egypt 2 Visiting Professor of Architectural Engineering, University of Nebraska – Lincoln, South 67th Street, Peter Kiewit Institute, Omaha, NE 3 University of Colorado at Boulder, CEAE Department • 428 UCB, Boulder, Colorado 80309-0428 U.S.A Email address: rizk2003@yahoo.com(A. A. Rizk), Gregor.Henze@Colorado.EDU(G. P. Henze) To cite this article: Ahmed A. Rizk, Gregor P. Henze. Survey of Airflow around Multiple Buildings. American Journal of Energy Engineering. Vol. 2, No. 1, 2014, pp. 27-36. doi: 10.11648/j.ajee.20140201.14 Abstract: This survey paper offers a review of past and present studies related to air flow around multiple building configurations to achieve energy savings and thermal comfort in hot climate regions in the presence of increased urbanization. The purpose of this review paper is to provide guidelines based on previous studies for the successful design of group housing in a hot and arid climate such as Egypt to improve air flow around multiple rows of buildings. This study presents several types of courtyard designs inside houses that provide direct air flow at windward sides inside compactly planned buildings. Next, air flow is described around one individual building and two buildings that have a passage between them. Furthermore, air flow around buildings is discussed to include several rows of buildings that range from rectangular linear to square shapes with flat and jack roofs, where the main goal is to achieve appropriate wind velocity at inlet surfaces, especially at the second and the third rows of buildings, and to avoid turbulence zones caused by wind around building. Finally, the effect of topography and urban mass on global wind velocity at the city scale is discussed. Keywords: Hot Climate, Courtyards, and Air Flow due to Wind Pressure around Buildings, Thermal Comfort with Natural Ventilation 1. Introduction This paper focuses on the previous study that related with wind flow around the different arrangements of buildings. Linear buildings are the main subject of this survey. Configuration of linear buildings forms between buildings around inner-courtyards and rows of multiple buildings. Unfavorable zones due to flow pattern performance are formed as a result of wind faced buildings. This survey study presents the previous solutions that can solve these zones. Aerodynamics shapes of buildings, chess –board arrangements of building rows, and jack roofs can decrease the effects of these zones. Many other solutions as open ground floor to decrease the unfavorable effect of stagnation zones in the wind-ward side of the buildings are not discussed in this review article. Also, the effect of the wind velocity due to Beaufourt scale is not discussed in this paper. Strong wind is completely different than weak wind in air flow around buildings. 1.1. Wind Flow Problem The article can describe the main problem of air flow around multiple buildings due to wind direction. Multiple buildings have a major problem related to air flow. First row of multiple rows of buildings that faced wind has maximum amount of wind. Next rows without carefully studying the fundamental of wind flow manners with buildings may have minimum amount of wind. Unfavorable wind movement due to wind direction is at inlet openings. A major problem is caused by the first row. Vortex and recirculation movement are a major problem of the next rows of multiple buildings. The methodology to solve the problem is presenting the climatic problem and how can the natural ventilation solve this climatic problem physically. Also, the relationship between air flow and natural ventilation is discussing in this article. The previous studies that deal with buildings around inner- courtyards, row of two buildings, multiple rows of buildings , and jack roofs are analyzed to solve the air flow problem that can affected directly in natural ventilation inside the buildings. Seriously, air flow around building is the main basic of natural ventilation that can achieve thermal comfort inside the buildings in the hot climate.