Erratic Scaled Residuals
 

Hey all,

I cannot achieve a converged result for one of my simulations which is of a NACA0015 airfoil with a flow of Mach 0.2 and AOA = 10 degrees.

I have successfully modelled the same airfoil at the same AOA through the range from Mach0.25 to Mach0.65

Unlike my other models the scaled residuals (attached) have an extremely "jagged" appearance over 1000 iterations, and hence, do not converge.

Does anyone know what the problem could be and how to solve it?

Much appreciated,
Tim.