TY - JOUR
T1 - A model for detachment of a partially wetting drop from a solid surface by shear flow
AU - Basu, Suddhasatwa
AU - Nandakumar, K.
AU - Masliyah, Jacob H.
N1 - Funding Information:
Authors acknowledge Alberta Oil Sand Technology Research Authority for their financial support.
PY - 1997/6/1
Y1 - 1997/6/1
N2 - Liquid drop detachment from a solid surface by simple sheat flow is modeled based on the experimental observations available in the literature. A liquid drop adhered to a solid surface deforms in the presence of a simple shear flew to form an advancing and a receding dynamic contact angle, The drop slides on the solid surface when the drag due to the shearing fluid overcomes the retentive force due to the contact angle hysteresis. A drop having an equilibrium contact angle, θ(e), approaching 180°detaches from the solid surface at the onset of its sliding motion. However, a drop with θ(e) much lower than 180°slides on the solid surface and will not detach. With further increase in the sheer rate, the sliding drop detaches from the solid surface when the lift force equals the adhesive, gravitational, and buoyancy forces of the drop. Based on this premise, an approximate mathematical model for the detachment of a partially wetting drop is constructed. The experimental results available in the literature for Pristane and Squalane drop detachment are compared for slide and lift as the mode of detachment. The critical sheat rate for the detachment of Pristane drops, having θ(e), of 175°, is predicted well by the model where sliding as the mode of detachment is assumed, whereas the experimental data for Squalane drops, having θ(e), of 126°, is well predicted by the model where lift is considered the mode of detachment.
AB - Liquid drop detachment from a solid surface by simple sheat flow is modeled based on the experimental observations available in the literature. A liquid drop adhered to a solid surface deforms in the presence of a simple shear flew to form an advancing and a receding dynamic contact angle, The drop slides on the solid surface when the drag due to the shearing fluid overcomes the retentive force due to the contact angle hysteresis. A drop having an equilibrium contact angle, θ(e), approaching 180°detaches from the solid surface at the onset of its sliding motion. However, a drop with θ(e) much lower than 180°slides on the solid surface and will not detach. With further increase in the sheer rate, the sliding drop detaches from the solid surface when the lift force equals the adhesive, gravitational, and buoyancy forces of the drop. Based on this premise, an approximate mathematical model for the detachment of a partially wetting drop is constructed. The experimental results available in the literature for Pristane and Squalane drop detachment are compared for slide and lift as the mode of detachment. The critical sheat rate for the detachment of Pristane drops, having θ(e), of 175°, is predicted well by the model where sliding as the mode of detachment is assumed, whereas the experimental data for Squalane drops, having θ(e), of 126°, is well predicted by the model where lift is considered the mode of detachment.
KW - Adhesive force
KW - Advancing and receding dynamic contact angles
KW - Contact angle hysteresis
KW - Drop detachment
KW - Lift force
KW - Partially wetting drop
KW - Sliding drop
KW - Steady shear flow
UR - http://www.scopus.com/inward/record.url?scp=0031171126&partnerID=8YFLogxK
U2 - 10.1006/jcis.1997.4856
DO - 10.1006/jcis.1997.4856
M3 - 文章
AN - SCOPUS:0031171126
SN - 0021-9797
VL - 190
SP - 253
EP - 257
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
IS - 1
ER -