I am having difficulty capturing the unsteadiness of a jet spray in Fluent. I've selected the unsteady option in the solver model menu and I'm using the k-epsilon viscosity model. Jet sprays are typically very unsteady and I'm using a significantly high Reynolds number (184,000), yet each of my time-steps gives me a nice, symmetric, smoothly-varying velocity contour plot. I've even initially disturbed the flow, but with no success.

Have any of you ever encountered this before or do you have any tips to better capture unsteadiness. I would greatly appreciate any and all advice. Thanks!

Tucker

Although I have not modelled the jet spray. But I think you can try two things: (i) define surface monitors at different locations in your domain and see whether there is change of velocity with time

(ii) Change the grid size (increase the no. of cells)and try to capture the unsteadiness.