UDF for sine wave in tank & cell count questions!

A8anato_psofimi

Hi. Does anyone have a sample or can anyone help me write a UDF for the creation of a sinusoidal wave at the end of a model testing tank(model basin)(2-D)? Also, is there a way to know if my cell count is sufficient without having to run it in Fluent to see convergence? What I mean is, does anyone know a ball park number? The tank is about 30m long, 2.5m high, and right now i have around 160,000 cells. Around half of the cells are structured and cover the majoriy of the tank, and the rest is unstructured near the wave absorbing beach (located at the opposite end from where the wave is generated) that I am testing for to find its reflection coefficient. The computer I will use I think is 2.6Ghz, with 512mb (maybe it is 1Gb, I dont remember). Any suggestions on around how many cells I should start out with?