-
沙尘暴和尘卷风等风沙运动的静电场是空气流场中沙粒间的碰撞摩擦带电及沙粒粒径的分层效应引起的, 本文耦合沙粒摩擦荷电模型和风沙运动气固两相流模型, 提出了离散单元法与计算流体动力学结合的数值方法. 数值模拟计算表明电荷呈中性的沙粒临界直径为300 μm; 在充分发展的水平风沙流中, 细小的沙粒带负电, 较大直径的沙粒带正电, 所模拟的沙粒带电的荷质比及水平风洞试验段的电场强度与实验测量值一致, 验证了风沙运动的电场-流场耦合模型及数值计算方法的合理性. 本文基于沙粒摩擦荷电机理的风沙运动气固两相流模型提供了理解风沙运动静电场产生的一种物理机理.The electrification of wind-blown sand, such as dust storms and dust devils, is known as the tribo-electric effect of sand particles and the stratification of different size particles. Combined with the grain electrification model, a new numerical method of gas-solid two-phase flow is developed for the simulation of wind-blown-sand two-phase flow, which is a hybrid method of computational fluid dynamics and discrete element method (CFD-DEM). In the developed wind-blown-sand two-phase flow of horizontal wind tunnel, the simulation results indicate that large size grains become positively charged while small size grains become negatively charged, and the critical diameter of grain with electric neutrality is about 300μm. The simulated charge-to-mass ratio and electric field intensity of the wind-blown sands in the field wind tunnel approach to the measured data, showing the rationality of this numerical method. The simulation also demonstrates that there occurs the maximum of electric field intensity over the sand bed of the field wind tunnel, which is the reason why the electric grounding of the field wind tunnel is used in experiment. The coupling of grain electrification model and gas-solid two-phase flow method provides an important tool for interpreting laboratory and field observations of wind-blown sands and insights into the physical dynamics of dust storms and dust devils as well.
-
Keywords:
- wind-sand movement /
- gas-solid two-phase flow /
- triboelectrification /
- discrete element method
[1] Anderson R S, Sorensen M, Willetts B B 1991 Acta. Mech. (supp1) 1
[2] Farrell W M, Delory G T, Cummer S A, Marshall J 2003 Geophys. Res. Lett. 30 2050
[3] Farrell W M, Smith P H, Delory G T 2004 J. Geophys. Res. 109 E03004
[4] Ju J J, Yna M H, Dong G R, Zhang H F 2003 Science China D 33 593 (in Chinese) [屈建军, 言穆弘, 董光荣, 张鸿发 2003 中国科学(D辑) 33 593]
[5] Renno N O, Abreu V J, Koch J 2004 J. Geophys. Res. 109 E07001
[6] Kok J F, Renno N O 2008 Phys. Rev. Lett. 100 014501
[7] Kok J F, Renno N O 2009 J. Geophys. Res. 114 D17204
[8] Zheng X J 2009 Mechanics of wind-blown sand movement (Berlin Heidelberg: Springer Verlag) p10
[9] Latham J 1964 Quart. J. R. Meteor. Soc. 90 91
[10] Zheng X J, Huang N, Zhou Y H 2003 J. Geophys. Res. 108 4322
[11] Huang N, Zheng X J 2000 Chin. Sci. Bull. 45 2232 (in Chinese) [黄宁, 郑晓静 2000 科学通报 45 2232]
[12] Zhou Y H, Guo X, Zheng X J 2002 Phys. Rev. E 66 021305
[13] Lu L Y, Gu Z L, Luo X L, Lei K B 2008 Acta Phys. Sin. 57 6939 (in Chinese) [鲁录义, 顾兆林, 罗昔联, 雷康斌 2008 57 6939].
[14] Zhou J, Cai L, Zhou F Q 2008 Chin. Phys. B 17 1535
[15] Tong Z H 2010 Acta Phys. Sin. 59 1884 (in Chinese) [仝志辉 2010 59 1884]
[16] Zhao J H, Zhang Q 2010 Acta Phys. Sin. 59 8954 (in Chinese) [赵建华, 张强 2010 59 8954]
[17] Gu Z L 2010 Eolian Dust: Near-surface Turbulence and Gas-Solid Two-Phase flow (Beijing: Science Press) p275 (in Chinese) [顾兆林 2010 风扬风尘-近地层湍流与气固两相流(北京: 科学出版社)第275页]
[18] Zhao Y Z, Cheng Y 2008 Acta Phys. Sin. 57 322 (in Chinese) [赵永志, 程易 2008 57 322]
[19] Zhao L L, Liu C S, Yan J X, Xu Z P 2010 Acta Phys. Sin. 59 1870 (in Chinese) [赵啦啦, 刘初升, 闫俊霞, 徐志鹏. 2010 59 1870]
[20] Ergun S 1952 Chem. Eng. Prog. 48 89
[21] Wen C Y, Yu Y Z 1966 Chem. Eng. Prog. 62 100
[22] Eigen M, DeMaeyer L 1958 Proc. Roy. Soc. London Ser. A 247 505
-
[1] Anderson R S, Sorensen M, Willetts B B 1991 Acta. Mech. (supp1) 1
[2] Farrell W M, Delory G T, Cummer S A, Marshall J 2003 Geophys. Res. Lett. 30 2050
[3] Farrell W M, Smith P H, Delory G T 2004 J. Geophys. Res. 109 E03004
[4] Ju J J, Yna M H, Dong G R, Zhang H F 2003 Science China D 33 593 (in Chinese) [屈建军, 言穆弘, 董光荣, 张鸿发 2003 中国科学(D辑) 33 593]
[5] Renno N O, Abreu V J, Koch J 2004 J. Geophys. Res. 109 E07001
[6] Kok J F, Renno N O 2008 Phys. Rev. Lett. 100 014501
[7] Kok J F, Renno N O 2009 J. Geophys. Res. 114 D17204
[8] Zheng X J 2009 Mechanics of wind-blown sand movement (Berlin Heidelberg: Springer Verlag) p10
[9] Latham J 1964 Quart. J. R. Meteor. Soc. 90 91
[10] Zheng X J, Huang N, Zhou Y H 2003 J. Geophys. Res. 108 4322
[11] Huang N, Zheng X J 2000 Chin. Sci. Bull. 45 2232 (in Chinese) [黄宁, 郑晓静 2000 科学通报 45 2232]
[12] Zhou Y H, Guo X, Zheng X J 2002 Phys. Rev. E 66 021305
[13] Lu L Y, Gu Z L, Luo X L, Lei K B 2008 Acta Phys. Sin. 57 6939 (in Chinese) [鲁录义, 顾兆林, 罗昔联, 雷康斌 2008 57 6939].
[14] Zhou J, Cai L, Zhou F Q 2008 Chin. Phys. B 17 1535
[15] Tong Z H 2010 Acta Phys. Sin. 59 1884 (in Chinese) [仝志辉 2010 59 1884]
[16] Zhao J H, Zhang Q 2010 Acta Phys. Sin. 59 8954 (in Chinese) [赵建华, 张强 2010 59 8954]
[17] Gu Z L 2010 Eolian Dust: Near-surface Turbulence and Gas-Solid Two-Phase flow (Beijing: Science Press) p275 (in Chinese) [顾兆林 2010 风扬风尘-近地层湍流与气固两相流(北京: 科学出版社)第275页]
[18] Zhao Y Z, Cheng Y 2008 Acta Phys. Sin. 57 322 (in Chinese) [赵永志, 程易 2008 57 322]
[19] Zhao L L, Liu C S, Yan J X, Xu Z P 2010 Acta Phys. Sin. 59 1870 (in Chinese) [赵啦啦, 刘初升, 闫俊霞, 徐志鹏. 2010 59 1870]
[20] Ergun S 1952 Chem. Eng. Prog. 48 89
[21] Wen C Y, Yu Y Z 1966 Chem. Eng. Prog. 62 100
[22] Eigen M, DeMaeyer L 1958 Proc. Roy. Soc. London Ser. A 247 505
计量
- 文章访问数: 7529
- PDF下载量: 708
- 被引次数: 0
下载:
