Nested computational fluid dynamic modeling of mean turbulent quantities estimation in complex topography using AROME-SIMRA

Abstract

This paper presents a validation of the AROME-SIMRA model, which is a nested computational fluid dynamics model that simulates both mesoscale and microscale phenomena. To validate the model, we analyzed 47 h of mean flow data collected by 13 three-dimensional sonic anemometers. These anemometers were mounted on tall masts located near the shoreline of Sulafjord, with heights ranging from 12 m to 95 m above the ground. Due to the difficulty measuring wind along the bridge span, analyzing flow conditions for the construction of a bridge that spans a vast fjord is a difficult process. Therefore, the primary objective of this study is to validate a nested macroscale–microscale model. This model will be utilized to analyze flow conditions across the span of the proposed bridge crossing in Sulafjord. The study explores the deviation between the measured and the simulated mean turbulence flow characteristics. Only records with the mean wind of 12 m s−1 and above at SulaNW met-mast are considered due to their relevance in buffeting response, which led to the identification of a limited number of sectors representative of strong wind conditions. Mean wind speed comparisons show a minimum correlation of 0.6 and a maximum of 0.9 for all the anemometers analyzed. For wind directions, a low correlation between observation and numerical simulation is obtained at SulaSW met-mast located southwest of Sulafjord. A high Angle of Attack is obtained for both simulation and measurements. However, the correlation is dependent on the mast location, wind direction, and anemometer height. Along the bridge span, the flow is largely horizontal for the northwestern flow.