Aerodynamics of Low-Rise Buildings: Challenges and Recent Advances in Experimental and Computational Methods

Abstract

Buildings are bluff bodies, compared to streamline objects, such as airfoil. Wind flow over buildings leads to separation and hence a complex spatial and temporal mechanism that governs the nature and intensity of aerodynamic forces. This complexity mainly comes from the transient nature of incident turbulent winds and the fluctuating flow pattern in the separation bubble. The study of building aerodynamics is vital for the evaluation of cladding pressures, drag, shear, and uplift forces that are essential for safe and economic design. Flow separation makes it challenging to estimate loads without referring to direct physical and/or computational simulation. For several decades, aerodynamic testing has been employed for the estimation of wind pressures and forces on buildings. However, for residential homes and low-rise buildings, it has been always a challenge to predict full-scale pressures by traditional wind tunnel testing, as per the lack of large turbulence and Reynolds number effects, among other factors. The mismatch in flow physics makes it difficult to scale up wind-induced loads as the process can be highly nonlinear, which is the case when full-scale pressure coefficients do not meet those from small-scale aerodynamic testing. This chapter presents the challenges in the modeling and evaluation of aerodynamic forces on low-rise buildings, along with recent advances in both experimental and computational methods.

Breaking Boundaries in Wind Engineering: LSU WISE Open-Jet Facility Revolutionizes Solar Panel and Building Design

“…Wind tunnel testing has traditionally been the cornerstone of wind engineering studies, providing insights into the behaviour of structures under wind loads. However, discrepancies between wall-bounded laboratory results and real-world field measurements have been noted, raising questions about the accuracy of scaled modelling and the effects of low Reynolds number [26,27,[35][36][37][38]. The limitations imposed by the Reynolds number law of similitude have prompted a shift towards large-scale testing, which can replicate full-scale physics [19,27,39].…”

“…However, discrepancies between wall-bounded laboratory results and real-world field measurements have been noted, raising questions about the accuracy of scaled modelling and the effects of low Reynolds number [26,27,[35][36][37][38]. The limitations imposed by the Reynolds number law of similitude have prompted a shift towards large-scale testing, which can replicate full-scale physics [19,27,39]. This has spurred the development of advanced testing facilities, such as the LSU WISE open-jet facility, which offers advantages in generating complete turbulence and accurately simulating real-world conditions [27,40,41].…”

“…Given these challenges, aerodynamic testing is pivotal in evaluating wind effects on buildings. However, traditional wall-bounded laboratory testing has limitations, particularly in replicating complete turbulence at high Reynolds numbers, which are crucial for accurately mimicking real-world conditions [26,27]. Recent studies advocate for large-scale testing facilities, such as the open-jet facility at Louisiana State University (LSU), which generates complete turbulence at higher Reynolds numbers, with minimal blockage effects [27,28].…”

“…However, traditional wall-bounded laboratory testing has limitations, particularly in replicating complete turbulence at high Reynolds numbers, which are crucial for accurately mimicking real-world conditions [26,27]. Recent studies advocate for large-scale testing facilities, such as the open-jet facility at Louisiana State University (LSU), which generates complete turbulence at higher Reynolds numbers, with minimal blockage effects [27,28]. These advances in testing techniques enable a more accurate estimation of wind pressures on buildings, ultimately contributing to developing more resilient and wind-resistant structural designs.…”

Effect of roof heights on dynamic characteristics of wind pressure on square low-rise buildings

“…With an increase in turbulence, the strong suction zones decreased in size and the fluctuating pressure coefficient was observed to be larger in more turbulent flows. The shape of a low-rise building has a considerable influence on the vortices and the wind loads induced on its roof [17,18]. The roof height is one of the most important factors affecting the flow field around a low-rise building.…”