starting vortex
Does anybody know, for starting vortex past an Airfoil, which BCs and also which strategies for time-dependent velocity should be used?
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Are you talking about the starting vortex simulation wise (i.e. starting from a non-physical initial field) or about the physical starting vortex from an accelerated airfoil??
huge difference :)= Cheers! |
I want to see what happend to the fluid past an Airfoil, if there is an acceleration in the fluid,
I do not know how I should increase the velocity and which BCs should I use? Is special strategy necessary? many Thanks! |
so you are trying to simulate the flow from an airfoil at rest up to some given speed? like an airplane taking off?
I have seen that done a few times, almost always with a moving mesh approach, but I'm no expert on this... What happens if you do sth like this: inflow BC: freestream, starting from u=0 to some u (of course, make sure your time discretization can handle this!!), outflow: extrapolation outflow. That would be my first try... |
I run this case with different BSc, but I could not get a good result. Do you think I should add a source term in NA-ST equations? or do you have another Idea?
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Quote:
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I compare my results with the experiment. I expect to have a vortex at the trailing edge (that agrees Helmholz theory too), but my results are the same as the results optained without the initial acceleration. I use DG (discontinous Galerkin) method.
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