Details
| Original language | English |
|---|---|
| Pages (from-to) | 757-764 |
| Number of pages | 8 |
| Journal | Computers and Fluids |
| Volume | 38 |
| Issue number | 4 |
| Early online date | 10 Oct 2008 |
| Publication status | Published - Apr 2009 |
Abstract
The accurate modelling of contact angle properties plays an important role in the simulation of free-surface micro flows. Taking capillary filling as an example, we first discuss the analytical solutions of a corresponding 1D description in certain limits and then derive an approximate analytical expression for the general case with constant contact angle. In case of a dynamic contact angle and contact line friction, the model is beyond an analytical treatment. We show that computational fluid dynamics (CFD) results exhibit a pronounced mesh dependence which is partly inherent to the modelling approach since the (non-integrable) viscous stress divergence at the three-phase contact line is commonly neglected in standard CFD simulations (see e.g. Hessel V, Hardt S, Löwe H. Chemical micro process engineering: fundamentals, modelling and reactions. Weinheim: Wiley-VCH; 2004). Moreover, the numerical description of contact angles suffers from artificial diffusion for the type of volume-of-fluid method used. Introduction of a macroscopic slip range in combination with a localised body force close to the contact line turns out to remedy both problems. Considering capillary filling as an example, we show that accurate, mesh independent solutions of fluid dynamic problems involving contact angle dynamics are obtained already on coarse meshes.
ASJC Scopus subject areas
- Computer Science(all)
- General Computer Science
- Engineering(all)
- General Engineering
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In: Computers and Fluids, Vol. 38, No. 4, 04.2009, p. 757-764.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Dynamic contact angles in CFD simulations
AU - Schönfeld, Friedhelm
AU - Hardt, Steffen
PY - 2009/4
Y1 - 2009/4
N2 - The accurate modelling of contact angle properties plays an important role in the simulation of free-surface micro flows. Taking capillary filling as an example, we first discuss the analytical solutions of a corresponding 1D description in certain limits and then derive an approximate analytical expression for the general case with constant contact angle. In case of a dynamic contact angle and contact line friction, the model is beyond an analytical treatment. We show that computational fluid dynamics (CFD) results exhibit a pronounced mesh dependence which is partly inherent to the modelling approach since the (non-integrable) viscous stress divergence at the three-phase contact line is commonly neglected in standard CFD simulations (see e.g. Hessel V, Hardt S, Löwe H. Chemical micro process engineering: fundamentals, modelling and reactions. Weinheim: Wiley-VCH; 2004). Moreover, the numerical description of contact angles suffers from artificial diffusion for the type of volume-of-fluid method used. Introduction of a macroscopic slip range in combination with a localised body force close to the contact line turns out to remedy both problems. Considering capillary filling as an example, we show that accurate, mesh independent solutions of fluid dynamic problems involving contact angle dynamics are obtained already on coarse meshes.
AB - The accurate modelling of contact angle properties plays an important role in the simulation of free-surface micro flows. Taking capillary filling as an example, we first discuss the analytical solutions of a corresponding 1D description in certain limits and then derive an approximate analytical expression for the general case with constant contact angle. In case of a dynamic contact angle and contact line friction, the model is beyond an analytical treatment. We show that computational fluid dynamics (CFD) results exhibit a pronounced mesh dependence which is partly inherent to the modelling approach since the (non-integrable) viscous stress divergence at the three-phase contact line is commonly neglected in standard CFD simulations (see e.g. Hessel V, Hardt S, Löwe H. Chemical micro process engineering: fundamentals, modelling and reactions. Weinheim: Wiley-VCH; 2004). Moreover, the numerical description of contact angles suffers from artificial diffusion for the type of volume-of-fluid method used. Introduction of a macroscopic slip range in combination with a localised body force close to the contact line turns out to remedy both problems. Considering capillary filling as an example, we show that accurate, mesh independent solutions of fluid dynamic problems involving contact angle dynamics are obtained already on coarse meshes.
UR - http://www.scopus.com/inward/record.url?scp=59849091740&partnerID=8YFLogxK
U2 - 10.1016/j.compfluid.2008.05.007
DO - 10.1016/j.compfluid.2008.05.007
M3 - Article
AN - SCOPUS:59849091740
VL - 38
SP - 757
EP - 764
JO - Computers and Fluids
JF - Computers and Fluids
SN - 0045-7930
IS - 4
ER -