A Numerical Study on the Impact of Building Dimensions on Airflow Patterns and Bed Morphology around Buildings at the Beach

Abstract

The attractiveness of beaches to people has led, in many places, to the construction of buildings at the beach–dune interface. Buildings change the local airflow patterns which, in turn, alter the sediment transport pathways and magnitudes. This induces erosion and deposition patterns around the structures. In this study, a numerical model is developed using the open-source computational fluid dynamics solver OpenFOAM. First, the model is used to predict the airflow patterns around a single rectangular building. The model predictions are validated with wind-tunnel data, which show good agreements. Second, a reference beach building is introduced and then the building dimensions are increased in length, width and height, each up to three times the reference building dimension. The impact of each dimensional extent on the near-surface airflow patterns is investigated. The results show that the near-surface airflow patterns are least dependent on the length of the building in the wind direction and they depend most on the width of the building perpendicular to the wind direction. Third, the convergence of the third-order horizontal near-surface velocity field is calculated to interpret the impact of changes in airflow patterns on potential erosion and deposition patterns around the building. The numerical predictions are compared with the observed erosion and sedimentation patterns around scale models in the field. The comparisons show satisfactory agreements between numerical results and field measurements.

Deposition patterns around buildings at the beach: Effects of building spacing and orientation

“…Therefore, further research by additional field experiments, controlled wind tunnel experiments, or CFD modelling of airflow around buildings (e.g. Pourteimouri et al, 2022), would be very valuable to further test and develop the theory. For instance, experiments with more repetitions or buildings with various length:width ratios would help to determine if other fractions than the so far used linearly interpolated steered fractions (i.e.…”

Cellular automaton modelling of the effects of buildings on aeolian bedform dynamics

“…The distance over which this surplus decays, and hence the initial deposition tail length, depends on the deposition probability p d . In reality, this deposition is also aided by horizontal flow convergence in the horseshoe vortex tails (Pourteimouri et al, 2022).…”

“…As wind speed slowly reverts to the undisturbed conditions, the sediment transport capacity decreases, explaining the downwind deposition. Apart from wind speed, the complex 3D flow field also plays a role here, with horizontal convergence promoting deposition in the horseshoe vortex tails (Pourteimouri et al, 2022). Directly adjacent to a building, the accelerated airflow can create scour.…”

Computational Fluid Dynamics Simulation of Tree Effects on Pedestrian Wind Comfort Around Coastline Building Resort

“…This recirculation was caused by a downward deflection of the flow over the front face of the structure to the ground, where it deflects again, resulting in near-bed flow in the opposite direction of the incoming wind direction. Research from Pourteimouri et al [69] reported that the magnitude of wind velocity steadily increases as the distance increases from the reattachment point until it eventually reaches the undisturbed wind velocity magnitude. Additionally, the findings show that the long building requires a longer distance for the wind to reach the undisturbed wind velocity magnitude.…”