[yhy20081016]

Hi, everybody. I am currently simulating 2D liquid sheet breakup using the VOF model in FLUENT. Both the gas and liquid are inviscid, and the surface tension has been considered. However, I found that it is very difficult to obtain a grid independent and time step independent solution.

I am working on absolute instability. I have constructed three meshes, of which the mesh size are 0.2(coarse mesh), 0.1(medium mesh) and 0.05(fine mesh), respectively. The number of cells are approximately 60000, 250000 and 1000000, respectively. For each mesh, I have tried several time step sizes. I use the non-iterative fractional step solver. A small pertubation is imposed on the sheet at t=0. The results, which is interface shapes at t=350, have been compared, which have been place in the attachments.



I found that there is no sign that the solution is converging with the decreasing of mesh size and time step size. I think maybe the cause is that the spatial accuracy of FLUENT is too low. Does anybody can give some advice? Thank you very much.