Experimental and Image Processing Investigation on the Diffusion of Dust Particles in the Atmospheric Area

Document Type : Research Article

Authors

1 Department of Mechanical Engineering, University of Tabriz, Iran

2 Department of Mechanical engineering, University of Tabriz, Iran

3 Tabriz University*

Abstract

The diffusion and transfer of dust particles in the atmospheric area were investigated with experimental and image processing methods. In a flat field, the rising of dust particles into the   air by plowing the field with a tractor and their spreading along the  surrounding environment as  a  real model of dust diffusion in the atmospheric area. The experiments carried out for specifying the particle-size distribution of the bed dust and its density. The experimental photos of dust diffusion were analyzed by image processing. The intensity of the diffusion of dust particles in the atmospheric area at the different roughness of surfaces for the different speeds of the tractor movement was obtained. The roughness of the surface increases the impact threshold and reduce the number of splashing particles. As particles velocities increase, the particles height increases and the proportion slope decreases at the high velocities. A relative concentration parameter Cα was defined. The results of this study compared with previous works based on this relative concentration. The concentration of dust particles decreases exponentially by increasing up to a certain height and after this height, changes in concentration are minor. Also, the role of mid-air collisions is significant, especially at high speeds.

Keywords

Main Subjects


[1] R. Greeley, J. Iversen, Wind as a Geological Process, 333 pp, Cambridge Univ. Process, New York, (1985).
[2] H. Tsoar, Bagnold, RA 1941: The physics of blown sand and desert dunes. London: Methuen, Progress in physical geography, 18(1) (1994) 91-96.
[3]  D. Beladjine, M. Ammi, L. Oger, A. Valance, Collision process between an incident bead and a three-dimensional granular packing, Physical Review E, 75(6) (2007) 061305.
[4]  M.P. Almeida, J.S. Andrade Jr, H.J. Herrmann, Aeolian transport layer, Physical review letters, 96(1) (2006) 018001.
[5]  M. Allen, D. Tildesley, Computer simulation of liquids, volume 18 of Oxford science publications, Oxford University Press, 45 (1989) 121.
[6]  J.F.   Kok,   N.O.   Renno,  A  comprehensive   numerical model of steady state saltation (COMSALT), Journal of Geophysical Research: Atmospheres, 114(D17) (2009).
[7]  H.  Gould,  J.  Tobochnik,  D.C.  Meredith,  S.E.  Koonin, S.R. McKay, W. Christian, An introduction to computer simulation methods: applications to physical systems, Computers in Physics, 10(4) (1996) 349-349.
[8]  J.D. Iversen, K.R. Rasmussen, The effect of wind speed and bed slope on sand transport, Sedimentology, 46(4) (1999) 723-731.
[9]  Y.  Zhou,  B.H.  Xu, A.-B. Yu,  P.  Zulli, An  experimental and numerical study of the angle of repose of coarse spheres, Powder technology, 125(1) (2002) 45-54.
[10]    R.  Di  Felice,  The  voidage  function  for  fluid-particle interaction systems, International Journal of Multiphase Flow, 20(1) (1994) 153-159.
[11]  B.  Xu,  A.  Yu,  Numerical  simulation  of  the  gas-solid flow in a fluidized bed by combining discrete particle method with computational fluid dynamics, Chemical Engineering Science, 52(16) (1997) 2785-2809.
[12]  B. Xu, A. Yu, S. Chew, P. Zulli, Numerical simulation of the gas–solid flow in a bed with lateral gas blasting, Powder Technology, 109(1-3) (2000) 13-26.
[13]  X.-Y. Zou, H. Cheng, C.-L. Zhang, Y.-Z. Zhao, Effects of the Magnus and Saffman forces on the saltation trajectories of sand grain, Geomorphology, 90(1-2) (2007) 11-22.
[14]  L.   Kang,   X.   Zou,   Vertical   distribution   of   wind– sand interaction forces in aeolian sand transport, Geomorphology, 125(3) (2011) 361-373.
[15]  D.  Jackson,  Potential  inertial  effects  in  aeolian  sand transport: preliminary results, Sedimentary Geology, 106(3-4) (1996) 193-201.
[16]  M.A. Rice, B.B. Willetts, I. McEwan, An experimental study of multiple grain‐size ejecta produced by collisions of saltating grains with a flat bed, Sedimentology, 42(4) (1995) 695-706.
[17]  J.  Crassous,  D.  Beladjine,  A.  Valance,  Impact  of  a projectile on a granular medium described by a collision model, Physical Review Letters, 99(24) (2007) 248001.
[18]  R.S. Anderson, P.K. Haff, Simulation of eolian saltation, Science, 241(4867) (1988) 820-823.
[19]  L.  Oger,  M.  Ammi,  A.  Valance,  D.  Beladjine,  Study  of the collision of one rapid sphere on 3D packings: Experimental and numerical results, Computers & Mathematics with Applications, 55(2) (2008) 132-148.
[20]    P. Nalpanis, J. Hunt, C. Barrett, Saltating particles over flat beds, Journal of Fluid Mechanics, 251 (1993) 661-685.
[21]    L.   Kang,   L.   Guo,   Eulerian–Lagrangian   simulation of aeolian sand transport, Powder technology, 162(2) (2006) 111-120.
[22]    L.  Kang,  D.  Liu,  Numerical  investigation  of  particle velocity distributions in aeolian sand transport, Geomorphology, 115(1-2) (2010) 156-171.
[23]    L.   Kang,   Discrete   particle   model   of   aeolian   sand transport: Comparison of 2D and 2.5 D simulations, Geomorphology, 139 (2012) 536-544.
[24]    D.J.  Sherman,  D.W.  Jackson,  S.L.  Namikas,  J. Wang, Wind-blown sand on beaches: an evaluation of models, Geomorphology, 22(2) (1998) 113-133.
[25]    Z. Li, D. Feng, S. Wu, A. Borthwick, J. Ni, Grain size and transport characteristics of non-uniform sand in aeolian saltation, Geomorphology, 100(3-4) (2008) 484-493.
[26]    W. Zhang, Y. Wang, S.-J. Lee, Two-phase measurements of wind and saltating sand in an atmospheric boundary layer, Geomorphology, 88(1-2) (2007) 109-119.
[27]    M.V. Carneiro, N.A. Araújo, T. Pähtz, H.J. Herrmann, Midair collisions enhance saltation, Physical review letters, 111(5) (2013) 058001.