Department News
The atomic detail of a wetting/de-wetting flow
Seminar Date
2003-03-11
Author
안지영
Date
2003-03-11
Views
1570
1. 제 목 : The atomic detail of a wetting/de-wetting flow
2. 연 사 : Professor Jonathan B. Freund
Department of Theoretical and Applied Mechanics
University of Illinois at Urbana-Champaign
3. 일 시 : 2003년 3월 27일 (목) 오후 5시
4. 장 소 : 301동 1512호 세미나실
5. 내 용 : When a liquid-vapor interface advances or recedes on a solid surface there is a crisis: the interface moves, but fluid on the should should not if there is a standard no-slip boundary condition on the solid. In standard continuum formulations a non-removable stress singularity results, which is often removed by relaxing the no-slip condition. More recently, modelers have suggested that a phase-change mass flux through the interface as another means of relieving the singularity. These models motivated the present effort. In the talk, I will discuss an ongoing study of flow in the vicinity of the advancing (wetting) and receding (de-wetting) solid-liquid-vapor contact lines of a two-dimensional (in the mean) liquid drop in thermodynamic equilibrium with its own vapor and moving steadily on an atomically smooth solid surface under the influence of an applied body force. Wetting and de-wetting are found to be asymmetric, counter to some predictions based on linear theory.There is a rolling flow of the liquid in the drop and fluid is ejected from the wetting common line into the bulk displaced vapor as observed macroscopically, but at the de-wetting common line substantial evaporation counteracts the anticipated injection of fluid from the bulk vapor.Evaporation is observed above the advancing contact line, but there is a net mass flux into the drop right at the contact line.There is evidence of slip flow just in advance of the wetting contact line, but not at the de-wetting line. Results are discussed in the context of phase-field models.
6. 문의 : 기계항공공학부 최 해 천 교수 (880-8361,1658)
2. 연 사 : Professor Jonathan B. Freund
Department of Theoretical and Applied Mechanics
University of Illinois at Urbana-Champaign
3. 일 시 : 2003년 3월 27일 (목) 오후 5시
4. 장 소 : 301동 1512호 세미나실
5. 내 용 : When a liquid-vapor interface advances or recedes on a solid surface there is a crisis: the interface moves, but fluid on the should should not if there is a standard no-slip boundary condition on the solid. In standard continuum formulations a non-removable stress singularity results, which is often removed by relaxing the no-slip condition. More recently, modelers have suggested that a phase-change mass flux through the interface as another means of relieving the singularity. These models motivated the present effort. In the talk, I will discuss an ongoing study of flow in the vicinity of the advancing (wetting) and receding (de-wetting) solid-liquid-vapor contact lines of a two-dimensional (in the mean) liquid drop in thermodynamic equilibrium with its own vapor and moving steadily on an atomically smooth solid surface under the influence of an applied body force. Wetting and de-wetting are found to be asymmetric, counter to some predictions based on linear theory.There is a rolling flow of the liquid in the drop and fluid is ejected from the wetting common line into the bulk displaced vapor as observed macroscopically, but at the de-wetting common line substantial evaporation counteracts the anticipated injection of fluid from the bulk vapor.Evaporation is observed above the advancing contact line, but there is a net mass flux into the drop right at the contact line.There is evidence of slip flow just in advance of the wetting contact line, but not at the de-wetting line. Results are discussed in the context of phase-field models.
6. 문의 : 기계항공공학부 최 해 천 교수 (880-8361,1658)
