Experimental and numerical aerodynamic analysis of an elevated beachfront house

Abstract

Elevating coastal houses enables residential communities to reduce the risk of flooding due to tropical cyclones. However, wind-induced damage during such events requires an understanding of the inherent wind forces to improve damage mitigation techniques and assessment of climate-related risk in insurance models. In this study, wind-tunnel experiments and computational fluid dynamics (CFD) simulations are conducted for a typical elevated 1:25 scale beachfront house, possessing a 5:12 pitched gable roof with overhanging eave. An atmospheric boundary layer (ABL) wind field is generated in a low-speed wind-tunnel to replicate conditions experienced during tropical cyclones. Testing is performed for a range of incident wind angles to understand the full aerodynamic consequences of strong winds. Measured pressure coefficient (Cp) distributions are compared with CFD simulations using steady-state and transient Delayed Detached-Eddy Simulation (DDES) within ANSYS Fluent 2021 R1. Net Cp values surrounding the overhanging eave are considered to evaluate the role of this typical geometrical feature. It was found that larger uplift suction occurred at incident wind angles of 45°and above, after which the suction remained stable. The roof panels are subjected to the greatest upward suction, where critical regions occur at the roof ridge. The size of the low-pressure regions is determined by the incident wind angle and ensuing flow separation wherein DDES is found to reproduce additional aerodynamic features arising from unsteady turbulent flow. DDES offers improved predictive capability when mean pressure forces are considered but falls short as an accurate means to efficiently evaluate peak Cp distributions.