Two-dimensional airflow modeling underpredicts the wind velocity over dunes

Strobl, Severin; Parteli, Eric J. R.; Pöschel, Thorsten

doi:10.1038/srep16572

Cited by 19 publications

(7 citation statements)

References 48 publications

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“…A constant pressure ( P = 0) is applied at the oulet of the channel in order to produce a pressure gradient in flow direction. Moreover, we apply a non-slip boundary condition to the entire fluid-solid interface comprising the soil and the fences, while the shear stress of the wind at the top wall is set equal to zero (see also refs 26, 46, 48 and 49). …”

Section: Methodsmentioning

confidence: 99%

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Optimal array of sand fences

Lima

Araújo

Parteli

et al. 2017

Sci Rep

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Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth’s climate. Many different types of fence have been designed and their effects on the sediment transport dynamics studied since many years. However, the search for the optimal array of fences has remained largely an empirical task. In order to achieve maximal soil protection using the minimal amount of fence material, a quantitative understanding of the flow profile over the relief encompassing the area to be protected including all employed fences is required. Here we use Computational Fluid Dynamics to calculate the average turbulent airflow through an array of fences as a function of the porosity, spacing and height of the fences. Specifically, we investigate the factors controlling the fraction of soil area over which the basal average wind shear velocity drops below the threshold for sand transport when the fences are applied. We introduce a cost function, given by the amount of material necessary to construct the fences. We find that, for typical sand-moving wind velocities, the optimal fence height (which minimizes this cost function) is around 50 cm, while using fences of height around 1.25 m leads to maximal cost.

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Section: Methodsmentioning

confidence: 99%

“…Moreover, we apply a non-slip boundary condition to the entire fluid-solid interface comprising the soil and the fences, while the shear stress of the wind at the top wall is set equal to zero (see also Refs. 26,46,48,49 ).…”

Section: Methodsmentioning

confidence: 99%

Optimal array of sand fences

Lima

Araújo

Parteli

et al. 2017

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, this model is often not practicable in many situations where the flows are confined in a channel. Examples of such flows include blockages and cavities in pipes [3][4][5], air flow in urban environments [6,7], environmental flows [8][9][10], engine and aerodynamic design [11][12][13], and mixing flows in diffusers, nozzles and pumps [14][15][16]. In such cases, it is important to account for the confining effect of the channel walls.…”

Section: Introductionmentioning

confidence: 99%

Turbulent shear layers in confining channels

Benham

Castrejón‐Pita

Hewitt

et al. 2018

Journal of Turbulence

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We present a simple model for the development of shear layers between parallel flows in confining channels. Such flows are important across a wide range of topics from diffusers, nozzles and ducts to urban air flow and geophysical fluid dynamics. The model approximates the flow in the shear layer as a linear profile separating uniform-velocity streams. Both the channel geometry and wall drag affect the development of the flow. The model shows good agreement with both particle image velocimetry experiments and computational turbulence modelling. The simplicity and low computational cost of the model allows it to be used for benchmark predictions and design purposes, which we demonstrate by investigating optimal pressure recovery in diffusers with non-uniform inflow.

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“…Changes in near surface wind over a barchan dune are well documented [86, [98][99][100][101]. On the windward side, wind flow decelerates before the toe of the dune, accelerates rapidly until the PLOS ONE crest of the dune where it reaches its maximum, followed by rapid deceleration in the lee of the dune, with a separation bubble of recirculation [73,86,98,[102][103][104] before the flow settles again further downwind of the barchan (Fig 9).…”

Section: Barchan Dune Flow Dynamicsmentioning

confidence: 99%

From Macro- to Microscale: A combined modelling approach for near-surface wind flow on Mars at sub-dune length-scales

Love

Jackson²,

Michaels³

et al. 2022

PLoS ONE

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The processes that initiate and sustain sediment transport which contribute to the modification of aeolian deposits in Mars’ low-density atmosphere are still not fully understood despite recent atmospheric modelling. However, detailed microscale wind flow modelling, using Computational Fluid Dynamics at a resolution of <2 m, provides insights into the near-surface processes that cannot be modeled using larger-scale atmospheric modeling. Such Computational Fluid Dynamics simulations cannot by themselves account for regional-scale atmospheric circulations or flow modifications induced by regional km-scale topography, although realistic fine-scale mesoscale atmospheric modeling can. Using the output parameters from mesoscale simulations to inform the input conditions for the Computational Fluid Dynamics microscale simulations provides a practical approach to simulate near-surface wind flow and its relationship to very small-scale topographic features on Mars, particularly in areas which lack in situ rover data. This paper sets out a series of integrated techniques to enable a multi-scale modelling approach for surface airflow to derive surface airflow dynamics at a (dune) landform scale using High Resolution Imaging Science Experiment derived topographic data. The work therefore provides a more informed and realistic Computational Fluid Dynamics microscale modelling method, which will provide more detailed insight into the surface wind forcing of aeolian transport patterns on martian surfaces such as dunes.

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Two-dimensional airflow modeling underpredicts the wind velocity over dunes

Cited by 19 publications

References 48 publications

Optimal array of sand fences

Optimal array of sand fences

Turbulent shear layers in confining channels

From Macro- to Microscale: A combined modelling approach for near-surface wind flow on Mars at sub-dune length-scales

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