Shape and Flow: The Essence of Architectural Aerodynamics

Basic aerodynamic theory is introduced to emphasise the influence of laminar and turbulent boundary layers on the characteristics of air flow around streamlined and non-streamlined bluff bodies such as rectangular buildings. Reynolds number is explained as the means to determine the relative influence of inertia forces to viscous forces at each point in an airflow. Bernoulliʹs equation is introduced as a means to evaluate changes in static and dynamic pressures in organised regions of air flow around buildings but not applicable in wake regions. Some common misconceptions on the influence of building shape on overall wind lift forces on buildings are discussed. The dominance of suction forces due to wind is demonstrated by comparing them to positive wind pressures at the same wind speed. Techniques for evaluating airflow through buildings are discussed including cautions regarding use of CFD on small computers.