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Three dimensional airflow patterns within a coastal trough-bowl blowout during fresh breeze to hurricane force winds

Smyth, T.A.G., Jackson, Derek and Cooper, Andrew (2013) Three dimensional airflow patterns within a coastal trough-bowl blowout during fresh breeze to hurricane force winds. Aeolian Research, 9 . pp. 111-123. [Journal article]

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URL: http://dx.doi.org/10.1016/j.aeolia.2013.03.002

DOI: 10.1016/j.aeolia.2013.03.002

Abstract

Wind flow within blowouts is extremely complex as streamline compression, expansion and reversal may occur over and around a single landform. As a result high resolution temporal and spatial measurements are required during a range of incident wind conditions to resolve near surface airflow patterns and turbulent structures. This study examined three-dimensional airflow within a coastal dune trough–bowl blowout using 15 ultrasonic anemometers (UAs) and a high resolution computational fluid dynamics model.Measured total wind speed and vertical wind speed behaved consistently through 5 Beaufort wind scales ranging from ‘fresh breeze’ to ‘strong gale’, increasing relative to incident wind speed, whilst wind direction at each UA did not alter. Due to the agreement of modelled and measured data, ‘hurricane’ (37 m/s) incident winds were also simulated and were consistent with modelled and measured wind direction at lower wind speeds. Modelled wind turbulence data was not compared with measured as only average conditions were simulated. However, the standard deviation of measured wind directionremained constant at each anemometer throughout the range of incident wind speeds, whilst the standard deviation of wind speed and turbulent kinetic energy increased relative to incident wind speed.This paper demonstrates that wind flow behaviour within blowouts throughout this range of wind speeds is governed by topography and is relative to, but does not change structurally with incident wind speed. As a result the extent of streamline compression, expansion, steering and reversal remain constant.

Item Type:Journal article
Keywords:aeolian CFD blowouts Ireland
Faculties and Schools:Faculty of Life and Health Sciences > School of Geography and Environmental Sciences
Faculty of Life and Health Sciences
Research Institutes and Groups:Environmental Sciences Research Institute > Coastal Systems
Environmental Sciences Research Institute
ID Code:25798
Deposited By: Professor Derek Jackson
Deposited On:22 Apr 2013 11:14
Last Modified:01 Apr 2015 15:03

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