Numerical simulation of wind field and sand flux in crescentic sand dunes

Abstract Sand flux is the key factor to determine the migration of sand dunes and the erosion to the surrounding environment. There are crescent-shaped sand dunes of various scales in the desert, and there are significant differences in spatial wind field and sand flux among them. However, due to th...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Huiwen Zhang, Zhen Wu, Jing Hu, Zhiping Zhang, Bin Xiao, Jianping Ma
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/f017145a828e47dcb1b91240283c6735
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:f017145a828e47dcb1b91240283c6735
record_format	dspace
spelling	oai:doaj.org-article:f017145a828e47dcb1b91240283c67352021-12-02T13:34:57ZNumerical simulation of wind field and sand flux in crescentic sand dunes10.1038/s41598-021-84509-x2045-2322https://doaj.org/article/f017145a828e47dcb1b91240283c67352021-03-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-84509-xhttps://doaj.org/toc/2045-2322Abstract Sand flux is the key factor to determine the migration of sand dunes and the erosion to the surrounding environment. There are crescent-shaped sand dunes of various scales in the desert, and there are significant differences in spatial wind field and sand flux among them. However, due to the difficulty of monitoring, it is difficult to continuously observe the spatial wind field and sand flux around the larger crescentic dunes. On the basis of the Reynolds-Average Navier–Stokes (RA-NS) equation and the stress and sand flux model, the distribution of wind field and sand flux of a circular dune with a height of 4.2 m and a length of about 100 m during the four evolutionary periods of the evolution into a crescentic dune was simulated in this study. By comparing with the measured results, we verified that the closer to the leeward side, the more the simulated values of the velocity in wind field and sand flux were in line with the measured results. In order to further analyze the influence of the height of dune and other relevant parameters on sand flux, we simulated the influence on wind field and sand flux by changing the air viscosity and wind velocity of upper boundary. We found that the air viscosity mainly affected the amount of deposited sand on the leeward side of sand dune, while the increase of wind velocity would undoubtedly increase the sand flux of the whole sand dune. In addition, the simulation results also showed that the influence of changes in height of dune on the turbulent intensity of leeward side was very significant, and the turbulent intensity increased with the height of dune. The height changes of tall dunes gradually affected the transport of sand caused by wind flow behind the leeward side because that the rotation of the wind flow would form new vortexes at the large pores behind the leeward side, which would increase the turbulent energy in space and thus would increase the distance of migration of the lifting sand. While the low sand dunes could not form extra small vortexes at the bottom of the leeward side, so the wind velocity was small and the eddy currents behind the leeward side were more stable. The simulation results indicated that wind velocity was not the only reason for increasing the amount of sand flux, and the fluctuation of wind flow caused by turbulence could also stimulate the movement of sand particles on the ground.Huiwen ZhangZhen WuJing HuZhiping ZhangBin XiaoJianping MaNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-18 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Huiwen Zhang Zhen Wu Jing Hu Zhiping Zhang Bin Xiao Jianping Ma Numerical simulation of wind field and sand flux in crescentic sand dunes
description	Abstract Sand flux is the key factor to determine the migration of sand dunes and the erosion to the surrounding environment. There are crescent-shaped sand dunes of various scales in the desert, and there are significant differences in spatial wind field and sand flux among them. However, due to the difficulty of monitoring, it is difficult to continuously observe the spatial wind field and sand flux around the larger crescentic dunes. On the basis of the Reynolds-Average Navier–Stokes (RA-NS) equation and the stress and sand flux model, the distribution of wind field and sand flux of a circular dune with a height of 4.2 m and a length of about 100 m during the four evolutionary periods of the evolution into a crescentic dune was simulated in this study. By comparing with the measured results, we verified that the closer to the leeward side, the more the simulated values of the velocity in wind field and sand flux were in line with the measured results. In order to further analyze the influence of the height of dune and other relevant parameters on sand flux, we simulated the influence on wind field and sand flux by changing the air viscosity and wind velocity of upper boundary. We found that the air viscosity mainly affected the amount of deposited sand on the leeward side of sand dune, while the increase of wind velocity would undoubtedly increase the sand flux of the whole sand dune. In addition, the simulation results also showed that the influence of changes in height of dune on the turbulent intensity of leeward side was very significant, and the turbulent intensity increased with the height of dune. The height changes of tall dunes gradually affected the transport of sand caused by wind flow behind the leeward side because that the rotation of the wind flow would form new vortexes at the large pores behind the leeward side, which would increase the turbulent energy in space and thus would increase the distance of migration of the lifting sand. While the low sand dunes could not form extra small vortexes at the bottom of the leeward side, so the wind velocity was small and the eddy currents behind the leeward side were more stable. The simulation results indicated that wind velocity was not the only reason for increasing the amount of sand flux, and the fluctuation of wind flow caused by turbulence could also stimulate the movement of sand particles on the ground.
format	article
author	Huiwen Zhang Zhen Wu Jing Hu Zhiping Zhang Bin Xiao Jianping Ma
author_facet	Huiwen Zhang Zhen Wu Jing Hu Zhiping Zhang Bin Xiao Jianping Ma
author_sort	Huiwen Zhang
title	Numerical simulation of wind field and sand flux in crescentic sand dunes
title_short	Numerical simulation of wind field and sand flux in crescentic sand dunes
title_full	Numerical simulation of wind field and sand flux in crescentic sand dunes
title_fullStr	Numerical simulation of wind field and sand flux in crescentic sand dunes
title_full_unstemmed	Numerical simulation of wind field and sand flux in crescentic sand dunes
title_sort	numerical simulation of wind field and sand flux in crescentic sand dunes
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/f017145a828e47dcb1b91240283c6735
work_keys_str_mv	AT huiwenzhang numericalsimulationofwindfieldandsandfluxincrescenticsanddunes AT zhenwu numericalsimulationofwindfieldandsandfluxincrescenticsanddunes AT jinghu numericalsimulationofwindfieldandsandfluxincrescenticsanddunes AT zhipingzhang numericalsimulationofwindfieldandsandfluxincrescenticsanddunes AT binxiao numericalsimulationofwindfieldandsandfluxincrescenticsanddunes AT jianpingma numericalsimulationofwindfieldandsandfluxincrescenticsanddunes
_version_	1718392769674739712

Numerical simulation of wind field and sand flux in crescentic sand dunes

Ejemplares similares