Airflow around conic tensile membrane structures

Sophisticated analytical models and computer software have facilitated the structural design of tensile membrane structures and this has produced a diverse and complex range of design and form solutions. The climate inside a typical fabric membrane enclosure is dependent on factors such as the shape (having a significant clear height) and the thermal properties of the thin “skin”, which differ considerably from traditional or more conventional “heavy” construction. However, there has been little consideration of the effect that these forms “shapes” have on their immediate environment, from the point of view of human comfort, even for the most basic of shapes. Tensile membrane structures can have an attractive dramatic effect and easily span a large area. In addition to the lighting and shading functions normally associated with tensile membrane skins, the topology of the construction type offers exciting opportunities to lend additional functionality and higher levels of comfort to the enclosure (ElNokaly et al, 2002). This paper describes the results of wind tunnel visualization and monitoring of the airflow patterns around and under conic tensile membrane structures covering open and semi-enclosed spaces. The experiments were conducted using a number of physical models representing a simple conical membrane structure. The study was designed primarily in order to ascertain the potential of conic membranes for modifying the microclimate and improving human comfort in their immediate vicinity. (Continued)