脉动风场下跃移沙粒对风的响应时间

doi:10.7522/j.issn.1000-694X.2020.00008

摘要/Abstract

摘要： 风沙流是大气边界层的典型气固两相流,输沙率对风速的响应滞后时间,被称为风沙流响应时间。通过野外测量发现风沙流响应时间与风速测量高度成正比,通过对瞬时风速进行信号分解并计算近地表输沙率与不同时间尺度风速信号之间的相关性,发现响应时间随风速频率的减小而增加。为进一步得到定量的规律,采用数值模拟的方法分析了周期来流风场中,风沙流响应时间随各种参数(周期\,湍流强度\,来流摩阻风速和测量高度等)的变化规律。模拟结果显示:响应时间与风速变化周期、来流摩阻风速成正比,与湍流强度和边界层高度成反比,输沙强度对跃移层外风速变化的响应时间沿高度先增加后减小。

关键词: 风沙流, 非定常风场, 响应时间, 数值模拟

Abstract: Wind-sand flow is a typical gas-solid two-phase flow occurring in the atmospheric boundary layer in which the sediment transport rate has a response time to the change of wind velocity named wind-sand flow response time. In this paper, we obtained that the response time of wind-sand flow is proportional to the measured height of wind velocity by field measurement. Based on the signal decomposition of instantaneous wind velocity and the correlation between near-surface sediment transport rate and wind velocity signal at different time scales, it is found that the response time increases with the decrease of wind velocity frequency. In order to obtain a quantitative rule, the response time of wind-sand flow with various parameters (period, turbulence intensity, incoming friction wind velocity and measured height, etc) in periodic flow field is analyzed by means of numerical simulation. The simulation results show that the response time is proportional to the period of wind velocity and the incoming friction wind velocity, and inversely proportional to the turbulence intensity and the height of the boundary layer. As height increases, response time first increases and then decreases.

Key words: wind-sand flow, unsteady wind field, response time, numerical simulation

中图分类号:

X169

靳婷, 彭晓庆, 王萍. 脉动风场下跃移沙粒对风的响应时间[J]. 中国沙漠, 2020, 40(2): 100-108.

Jin Ting, Peng Xiaoqing, Wang Ping. Response time of saltation to wind in pulsatory wind field[J]. Journal of Desert Research, 2020, 40(2): 100-108.

参考文献

[1] Butterfield G R.Transitional behaviour of saltation:wind tunnel observations of unsteady winds[J].Journal of Arid Environments,1998,39(3):377-394.
[2] Schnfeldt H J,von Lwis S.Turbulence-driven saltation in the atmospheric surface layer[J].Meteorologische Zeitschrift,2003,12(5):257-268.
[3] Baas A C W.Wavelet power spectra of aeolian sand transport by boundary layer turbulence[J].Geophysical Research Letters,2006,33(5):L05403.
[4] Martin R L,Barchyn T E,Hugenholtz C H,et al.Timescale dependence of aeolian sand flux observations under atmospheric turbulence[J].Journal of Geophysical Research:Atmospheres,2013,118(16):9078-9092.
[5] Zheng X.Mechanics of Wind-blown Sand Movements[M].Berlin,Germany:Springer Science & Business Media,2009.
[6] Pfeifer S,Schnfeldt H J.The response of saltation to wind speed fluctuations[J].Earth Surface Processes and Landforms,2012,37(10):1056-1064.
[7] Butterfield G R.Near-bed mass flux profiles in aeolian sand transport:high-resolution measurements in a wind tunnel[J].Earth Surface Processes and Landforms,1999,24(5):393-412.
[8] Butterfield G R.Graintransport rates in steady and unsteady turbulent airflows[M]//Aeolian Grain Transport 1.Vienna,Austria:Springer,1991:97-122.
[9] Butterfield G R.Sand transport response to fluctuating wind velocity[J].Turbulence:Perspectives on Flow and Sediment Transport,1993,13:305-335.
[10] Shao Y,Raupach M R.The overshoot and equilibration of saltation[J].Journal of Geophysical Research:Atmospheres,1992,97(D18):20559-20564.
[11] Andreotti B,Claudin P,Pouliquen O.Measurements of the aeolian sand transport saturation length[J].Geomorphology,2010,123(3/4):343-348.
[12] Li B,Neuman C M K.A wind tunnel study of aeolian sediment transport response to unsteady winds[J].Geomorphology,2014,214:261-269.
[13] Ungar J E,Haff P K.Steady state saltation in air[J].Sedimentology,1987,34(2):289-299.
[14] Werner B T.A steady-state model of wind-blown sand transport[J].Journal of Geology,1990,98(1):1-17.
[15] Anderson R S,Haff P K.Wind modification and bed response during saltation of sand in air[M]//Aeolian Grain Transport 1.Vienna,Austria:Springer,1991:21-51.
[16] McEwan I K,Willetts B B.Numerical model of the saltation cloud[M]//Aeolian Grain Transport 1.Vienna,Austria:Springer,1991:53-66.
[17] Srensen M.An analytic model of wind-blown sand transport[M]//Aeolian Grain Transport 1. Vienna,Austria:Springer,1991:67-81.
[18] Spies P J,McEwan I K.Equilibration of saltation[J].Earth Surface Processes and Landforms,2000,25(4):437-453.
[19] Zheng X J,Huang N,Zhou Y.The effect of electrostatic force on the evolution of sand saltation cloud[J].The European Physical Journal E,2006,19(2):129-138.
[20] Ma G S,Zheng X J.The fluctuation property of blown sand particles and the wind-sand flow evolution studied by numerical method[J].The European Physical Journal E,2011,34(5):54.
[21] Mayaud J R,Bailey R M,Wiggs G F S,et al.Modelling aeolian sand transport using a dynamic mass balancing approach[J].Geomorphology,2017,280:108-121.
[22] McEwan I K,Willetts B B.Sand transport by wind:a review of the current conceptual model[J].Geological Society of London Special Publications,1993,72(1):7-16.
[23] Bauer B O,Davidson-Arnott R G D,Nordstrom K F,et al.Indeterminacy in aeolian sediment transport across beaches[J].Journal of Coastal Research,1996:641-653.
[24] Stout J E,Zobeck T M.Intermittent saltation[J].Sedimentology,1997,44(5):959-970.
[25] Baas A C W,Sherman D J.Spatiotemporal variability of aeolian sand transport in a coastal dune environment[J].Journal of Coastal Research,2006:1198-1205.
[26] Jackson D W T.A new,instantaneous aeolian sand trap design for field use[J].Sedimentology,1996,43(5):791-796.
[27] Ellis J T,Sherman D J,Farrell E J,et al.Temporal and spatial variability of aeolian sand transport:implications for field measurements[J].Aeolian Research,2012,3(4):379-387.
[28] Bauer B O,Davidson-Arnott R G D.Aeolian particle flux profiles and transport unsteadiness[J].Journal of Geophysical Research:Earth Surface,2014,119(7):1542-1563.
[29] Martin R L,Kok J F.Distinct thresholds for the initiation and cessation of aeolian saltation from field measurements[J].Journal of Geophysical Research:Earth Surface,2018,123(7):1546-1565.
[30] Sterk G,Jacobs A F G,Van Boxel J H.The effect of turbulent flow structures on saltation sand transport in the atmospheric boundary layer[J].Earth Surface Processes and Landforms,1998,23(10):877-887.
[31] Wiggs G F S,Baird A J,Atherton R J.The dynamic effects of moisture on the entrainment and transport of sand by wind[J].Geomorphology,2004,59(1/2/3/4):13-30.
[32] Jackson D W T,McCloskey J.Preliminary results from a field investigation of aeolian sand transport using high resolution wind and transport measurements[J].Geophysical Research Letters,1997,24(2):163-166.
[33] Carneiro M V,Rasmussen K R,Herrmann H J.Bursts in discontinuous Aeolian saltation[J].Scientific Reports,2015,5:11109.
[34] Baas A C W,Sherman D J.Formation and behavior of aeolian streamers[J].Journal of Geophysical Research:Earth Surface,2005,110(F3):3011-3026.
[35] Sherman D J,Houser C,Ellis J T,et al.Characterization of aeolian streamers using time-average videography[J].Journal of Coastal Research,2013,65(sp2):1331-1336.
[36] 王萍,郑晓静.野外近地表风沙流脉动特征分析[J].中国沙漠,2013,33(6):1622-1628.
[37] Wang P,Zheng X.Saltation transport rate in unsteady wind variations[J].The European Physical Journal E,2014,37(5):40.
[38] Kok J F,Renno N O.A comprehensive numerical model of steady state saltation (COMSALT)[J].Journal of Geophysical Research:Atmospheres,2009,114(D17):17204-17223.
[39] Rice M A,Willetts B B,McEwan I K.An experimental study of multiple grain-size ejecta produced by collisions of saltating grains with a flat bed[J].Sedimentology,1995,42(4):695-706.
[40] Kang L,Guo L,Liu D.Reconstructing the vertical distribution of the aeolian saltation mass flux based on the probability distribution of lift-off velocity[J].Geomorphology,2008,96(1/2):1-15.
[41] Andreotti B.A two-species model of aeolian sand transport[J].Journal of Fluid Mechanics,2004,510:47-70.
[42] Beladjine D,Ammi M,Oger L,et al.Collision process between an incident bead and a three-dimensional granular packing[J].Physical Review E,2007,75(6):061305.
[43] Bagnold R A.ThePhysics of Wind Blown Sand and Desert Dunes[M].London,UK:Methuen,1941.
[44] Wang G,Zheng X.Very large scale motions in the atmospheric surface layer:a field investigation[J].Journal of Fluid Mechanics,2016,802:464-489.
[45] Liu H Y,Wang G H,Zheng X J.Spatial length scales of large-scale structures in atmospheric surface layers[J].Physical Review Fluids,2017,2(6):064606.
[46] Feldmann D,Bauer C,Wagner C.Computational domain length and Reynolds number effects on large-scale coherent motions in turbulent pipe flow[J].Journal of Turbulence,2018,19(3):274-295.
[47] Lotfy E R,Zaki S A,Harun Z.Modulation of the atmospheric turbulence coherent structures by mesoscale motions[J].Journal of the Brazilian Society of Mechanical Sciences and Engineering,2018,40(4):178.
[48] 刘江,王元,杨斌.高频测量输沙浓度对湍流脉动的频率响应[J].西安交通大学学报,2010,44(11):118-123.
[49] Spies P J,McEwan I K,Butterfield G R.One-dimensional transitional behaviour in saltation[J].Earth Surface Processes and Landforms,2000,25(5):505-518.
[50] Zhang H,Zheng X J,Bo T L.Electric fields in unsteady wind-blown sand[J].The European Physical Journal E,2014,37(2):13.
[51] Davenport A G.The spectrum of horizontal gustiness near the ground in high winds[J].Quarterly Journal of the Royal Meteorological Society,1961,87(372):194-211.
[52] Berman S.Estimating the longitudinal wind spectrum near the ground[J].Quarterly Journal of the Royal Meteorological Society,1965,91(389):302-317.
[53] Kaimal J C,Wyngaard J C J,Izumi Y,et al.Spectral characteristics of surface-layer turbulence[J].Quarterly Journal of the Royal Meteorological Society,1972,98(417):563-589.
[54] Wyngaard J C.Atmospheric turbulence[J].Annual Review of Fluid Mechanics,1992,24(1):205-234.
[55] Weaver C M,Wiggs G.Turbulent flow and sand dune dynamics:identifying controls on aeolian sediment transport[C]//AGU Fall Meeting Abstracts.2007.
[56] Yang X I A,Sadique J,Mittal R,et al.Integral wall model for large eddy simulations of wall-bounded turbulent flows[J].Physics of Fluids,2015,27(2):025112.
[57] Rasmussen K R,Srensen M.Vertical variation of particle speed and flux density in aeolian saltation:measurement and modeling[J].Journal of Geophysical Research:Earth Surface,2008,113(F2):F02S12.
[58] Creyssels M,Dupont P,El Moctar A O,et al.Saltating particles in a turbulent boundary layer:experiment and theory[J].Journal of Fluid Mechanics,2009,625:47-74.
[59] Ho T D,Valance A,Dupont P,et al.Scaling laws in aeolian sand transport[J].Physical Review Letters,2011,106(9):094501.
[60] Kok J F,Parteli E J R,Michaels T I,et al.The physics of wind-blown sand and dust[J].Reports on Progress in Physics,2012,75(10):106901.
[61] Durán O,Andreotti B,Claudin P.Numerical simulation of turbulent sediment transport,from bed load to saltation[J].Physics of Fluids,2012,24(10):103306.
[62] Dupont S,Bergametti G,Marticorena B,et al.Modeling saltation intermittency[J].Journal of Geophysical Research:Atmospheres,2013,118(13):7109-7128.
[63] Zhou Y H,Guo X,Zheng X J.Experimental measurement of wind-sand flux and sand transport for naturally mixed sands[J].Physical Review E,2002,66(2):021305.
[64] Kawamura R.Study on sand movement by wind[R].Tokyo,Japan:Institute of Science and Technology,Tokyo University,1951:95-112.
[65] Lettau K.Experimental and micrometeorological field studies of dune migration[M]//Exploring in the Worlds Driest Climate.1978:110-147.