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Transient convergence problem

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Old   June 23, 2017, 15:21
Default Transient convergence problem
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I am trying to simulate a NACA0012 airfoil that slowly rotates from Angle of attack=0 to AOA=1deg.
I'm doing this via a rotating mesh ( a circle around the airfoil that rotates at 1deg per second, and in between I use 500 timesteps.

When I solve transient he converges to a wrongful Lift coefficient (but drag coefficient is correct). Then if I do steady state simulation at AOA=1 he gives me the correct result for both coefficients.

I already tried to reduce the rotation speed of the airfoil, increase the amount of time steps, increase iterations/timestep, reduce time step size,... But nothing has a significant effect on the lift coefficient.

Before I start the transient simulation I made sure to first solve static analysis to have a good estimation for the flowfield at AOA=0

Ma= 0,023
Re= 219.000
I use turbulence model: Transition SST because for the application a correct estimation of the transition point is important.

Before I had exactly the same setup with Re=3e6 and then everything worked perfectly

I hope somebody has some advice at what I could look at or anything I could be doing wrong here.
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rotating mesh, transient sst, turbulence analysis

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