TY - JOUR
T1 - Experimental study of liquid drop impact onto a powder surface
AU - Marston, Jeremy
AU - Thoroddsen, Sigurdur T
AU - Ng, Waikiong
AU - Tan, Reginald
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by the Science and Engineering Research Council of A*STAR (Agency for Science, Technology and Research), Singapore. The authors would like to thank Ng Junwei for assistance in measurements of the powder size distribution and liquid viscosities.
PY - 2010/11
Y1 - 2010/11
N2 - The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.
AB - The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.
UR - http://hdl.handle.net/10754/561510
UR - https://linkinghub.elsevier.com/retrieve/pii/S0032591010002500
UR - http://www.scopus.com/inward/record.url?scp=77955518700&partnerID=8YFLogxK
U2 - 10.1016/j.powtec.2010.05.012
DO - 10.1016/j.powtec.2010.05.012
M3 - Article
SN - 0032-5910
VL - 203
SP - 223
EP - 236
JO - Powder Technology
JF - Powder Technology
IS - 2
ER -