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Calculation time for lift on 3D wing

Question asked by Josiah Lund on Feb 23, 2015
Latest reply on Jun 26, 2020 by Steve Grossman

All,

 

I have recently been working quite a bit with SW flow sim and have gotten good results in 2D. I am working my way up and have now begun trying to tackle a 3D wing. Find my 2D simulation here: Lift Coefficient on 2D Airfoil

 

I have been able to somewhat successfully reach convergence for the 3D case. My concern is that even on a relatively powerful computer, calculation time is in the neighborhood of 24-30 hours. How can I keep this as low as possible yet ensure I am getting accurate results?

 

I am able to check values for this simulation, but the next step is to include the fuselage of my plane, and I will have nothing to compare with so I want to perfect my methods before moving on.

 

The wing I am simulating is built from the same airfoil as the 2D simulation.

XFLR5 Wing.PNG

Rather that go into details on the setup again, I will jump straight to my results and different methods I took.

 

The Mesh was created using a level 1 initial mesh with a level 5 refine set to refine every 1 travel starting with the 2nd full travel. The resulting mesh is pictured below.

 

Mesh Top.PNG

Mesh Side detail.PNG

Mesh Front.PNG

Mesh Front Detail.PNG

The simulation converged after after 21 hours with a mesh of 5.75 million fluid cells + 320,000 partial cells. The converged value for CL is 0.317, off from the theoretical value by about 6%.

 

Goal Plot.PNG

I am okay with the accuracy, but would like to know if there is a way that I could set the problem up differently to shorten the calculation time without bringing down the accuracy of the simulation.

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