[alimea]

Hi everybody

I ran the droplet impact tutorial. However, when I saw the results in ParaView, I faced some teeth on the droplet perimeter (the interface with the air), as can be seen in the following pic.

https://pasteboard.co/K2qPPzE.jpg

While in the reference paper one doesn't see these teeth.

https://pasteboard.co/K2qPiIi.jpg

I have made many changes in the setup case, e.g. increasing and decreasing Betta, increasing Re, decreasing Wi, decreasing and increasing the dt, generating a very smaller grid, etc. But the teeth remained!

Even, I set zero values for etaP and lambda, showing a Newtonian fluid, but they remained. However, when I chose Newtonian constitutive eq. the teeth would be removed. This showed me that this is just because of the numerical process of discretization or solution of Oldroyd-B constitutive eq.

Note: Can you explain to me physically why the authors set zero value for surface tension?
As we know, the droplet impact behavior is totally under the effect of surface tension forces. Nevertheless, when I set a non-zero value for the surface tension coef, e.g. 0.07 N/m, teeth got smaller. But the reference paper solved this problem using sigma = 0 and I must solve it in this situation and get the correct answer.

Do you know what they are, and how to solve them?

Thanks