Q: Airfoil Low Reynolds
 

I am design wind turbine 1KW. So I need to simulate predict airfoil in low reynolds. I used NACA 0012 for test. I want to know:
1/ In low reynolds you will use unsteady or steady for time.
2/ Why did my coefficient drag decrease follow time when I use k-epsilon in condition unsteady? I think it will oscillate at a point.

1- You should use steady scheme to analyze your problem.
2-Oscillation during solution convergence is a common thing for aerodynamic coefficients.

Bests.

How low is your Re...? You might be better to use a Low Re k-e model.