دانلود رایگان مقاله بررسی مدل سازی دینامیک سیالات محاسباتی (CFD) جریان هوا بر لندفرم بادی

abstract

Aeolian landforms occur on all earths’ continents as well as on Mars, Titan and Venus and are typically formed where sediment is eroded and/or deposited by near surface wind flow. As wind flow approaches an aeolian landform, secondary flow patterns are created that cause wind to deviate in both speed and direction, producing complex patterns of sediment erosion, deposition and transportation. Computational Fluid Dynamics (CFD) modelling of wind flow has become a common tool to predict and understand secondary wind flow and resulting sediment transport. Its use has progressed from simulating wind flow over simple two dimensional dune shapes, to calculating a multitude of flow parameters over a range of increasingly complex landforms. Analysis of 25 peer reviewed journal articles, found that CFD has been crucial to providing additional insight to flow dynamics on the stoss slope of dunes, the structure and nature of wind flow separation in the lee of landforms and information on localised wind flow variations in large-scale dune fields. The findings of this assay demonstrate that further research is required regarding the parameterisation and modelling of surface roughness, the incorporation of accurate sediment transport to wind flow models, and the prediction of topographic surface changes. CFD is anticipated to be increasingly utilised in aeolian geomorphology and this work aims to be a starting point for aeolian geomorphologists wishing to better understand and review the utilisation of the technique to date.

5. Conclusion

This review demonstrates that CFD can be used to model the wind flow around natural aeolian landforms and replicate field and wind tunnel measurements. The technique has been evidenced as a valuable tool to aeolian researchers investigating wind flow separation, steering and acceleration over isolated landforms and landforms integrated within a landscape. CFD is likely to be an increasingly utilised tool in aeolian research and future research is expected to include the prediction of erosion and deposition by CFD, increased integration of LES turbulence modelling and the use of discrete roughness elements to examine the boundary layer dynamics in vegetation.