In VOF model, we simulate micro-droplet generation and flow behavior defining static contact angle. But, the contact angle of the droplet keeps changing as it flows in the channel if its touching the surface. I would like to know, at
When we need to consider dynamic contact angle ?
What kind of benefits we will get if we choose it?
Does static condition will work in all cases? If Yes, what should be the range of dynamic contact angle change which will allow us to consider static angle?
Hi!
I see no benefits in choosing static angle. Measuring dynamic angles across a surface gives a better representation as you get more data points. Changes in dynamic angle are common along the surface and depending on the surface finishing they may be great. But that’s the result then :)
Of course, adjusting measurement conditions can improve the results.
However, in case you go for static angle, make several tests around your sample surface. In static measurement there is a huge risk of measuring only artefacts, impurities or roughness where your drop pins.
I hope this helps!
Dear Sripada,
Since you simulations anyway you can do benchmark simulations. There are some scaling laws when it comes to wetting, like the Tanner's law. If you can match these scalings with your static contact angle model everything should be fine.
However I would suggest to be critical with your numerical results, because the VOF method with it's interface reconstruction is far from being trivial.
Always try to validate against experimental results!
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