Hi; I want to analys a waterfal. How can i do it? thanks

Dear Rawin:

You have to use stratified two phase model for this problem. I fluent use have to use VOF model. Guess the waterfall dimensions first and patch it to FLUENT. Use second order discretization (QIUCK prefered). You have to adjust your mesh density and initial condition carefully. Also, consider following link; Niagara Waterfall is simulated already: http://www.cfdcanada.com/Falls1.pdf

Best Regards MEhdi Ghoddosy

Hi MEhdi Ghoddosy Thanks for your response.I should simulate free surface flow of that.I think Flow domain is consist of moving and deforming mesh.am i right?if yes how can i do it?

Dear Rawin:

You do not need moving or deforming mesh for free surface flow modeling. In free sufrace modeling flooding and drying algoritms are used and there is not a deforming mesh. The flooding and drting algoritm decets that the cells in the water surface boundary turn off or on(Wet or Dry). Here, in FLUENT an advanced model is utilized named Volume of Fluid that let you to model two(or more)phase stratified flow. You can model dense flows with this model too. It does not need moving mesh. This model defines a vulome fraction for each cell of computaional domain that decets what fraction of each cell is filled with each fluid (Air and water for your case). A mass transfer and continuity eq. is solved for boundary cells and momnetum eqs. is averaged over each boundary cell. Using this method you can model complicated free surface problems, but initial condotions are most important in your model. You have to give a good guess to your problem. Use excisting litrature on waterfalls to achieve an exact guess for your problem. For example, USBR experiments is a good initial condition guess.

Best Regards Mehdi Ghoddosy

Hi thank you Mehdi Ghoddosy.it was helpful. Best Regards