Use mesh motion to introduce angle for static simulation

dancfd · November 18, 2010, 19:59

Hello all,

To begin validating my 2-D oscillating airfoil simulation, I need to run tests on a static airfoil deflected at a few angles of attack, and compare the results with experiment. While I could create a new blockMeshDict with the airfoil at a different angle each time, the mesh at each angle would not accurately reflect the mesh of a dynamic case where the mesh is being deformed, thus invalidating my validation effort. Case in point - my previous posts about a deflecting flap that keeps turning the mesh inside out. I can run blockMesh with the flap and airfoil at any angle and get a perfect mesh, however if I start with a neutral angle and try to move it, the mesh deteriorates.

I am using dynamicMotionSolverFvMesh, displacementLaplacian and angularOscillatingDisplacement on the moving boundary. Any idea on how to use OF to insert a step rotation (if I can call it that)?

Thanks,
Dan

dancfd · November 18, 2010, 20:15

It looks like I posted the previous too soon, I apologize. For anyone wondering, set angle0 != 0 and omega = 0.

The mesh is still no good, though. Using inverseDistance diffusivity, the trailing edge still turns the mesh inside out - I need an angle of attack of 18 degrees. RBFmotion can accommodate such a large change in angle of attack, however it is very computationally expensive and there is no "angle0" equivalent as with angularOscillatingDisplacement - bringing me back to my first problem.

Any ideas?

Dan

November 18, 2010, 19:59	Use mesh motion to introduce angle for static simulation	#1
dancfd Senior Member Daniel Join Date: Jul 2009 Location: Montreal, Canada Posts: 156 Rep Power: 17	Hello all, To begin validating my 2-D oscillating airfoil simulation, I need to run tests on a static airfoil deflected at a few angles of attack, and compare the results with experiment. While I could create a new blockMeshDict with the airfoil at a different angle each time, the mesh at each angle would not accurately reflect the mesh of a dynamic case where the mesh is being deformed, thus invalidating my validation effort. Case in point - my previous posts about a deflecting flap that keeps turning the mesh inside out. I can run blockMesh with the flap and airfoil at any angle and get a perfect mesh, however if I start with a neutral angle and try to move it, the mesh deteriorates. I am using dynamicMotionSolverFvMesh, displacementLaplacian and angularOscillatingDisplacement on the moving boundary. Any idea on how to use OF to insert a step rotation (if I can call it that)? Thanks, Dan

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November 18, 2010, 20:15		#2
dancfd Senior Member Daniel Join Date: Jul 2009 Location: Montreal, Canada Posts: 156 Rep Power: 17	It looks like I posted the previous too soon, I apologize. For anyone wondering, set angle0 != 0 and omega = 0. The mesh is still no good, though. Using inverseDistance diffusivity, the trailing edge still turns the mesh inside out - I need an angle of attack of 18 degrees. RBFmotion can accommodate such a large change in angle of attack, however it is very computationally expensive and there is no "angle0" equivalent as with angularOscillatingDisplacement - bringing me back to my first problem. Any ideas? Dan