Sir, I have done the simulation and it is converging and the mass flux, drag monitor is also a flat curve without any fluctuations.
I don't think there are any problems related to mesh around diffuser inlet as it is structured mesh.
Sir, Is it anything related to reference values I have entered ? As it is a 2D problem, considering depth of 1m and diameter of diffuser inlet as D. I have specified both depth, as diameter of nozzle inlet and area as (1*D).
And rest of the parameters in reference value box are the default values.
But still even my probe value is also around 1.2 which doesn't make sense to me. Can you tell me where I am going wrong.