Compressible flow too many iteration
 

Hi everyone, my name is ian
I am new in Ansys, it is about my 30 days learning this software
I am doing my research for my bachelor degree but I face a problem

I want to re-create the simulation that published in a journal as a validation for my research, but I can't get the convergence

my case is a steam ejector( high pressure steam goes into e a nozzle with high velocity and low pressure)
this pressure will suct the air behind,
then the mixture goes into a converging diverging section

https://i.postimg.cc/YCQyMYLG/steam-ejector.png


my set up is
density based,steady,axisymetric
energy equation on, K omega SST
water vapor(density:ideal gas, viscosity:sutherland)

Boundary Condition:
Pressure inlet1= 800KPa ,Tsaturation
Pressure inlet2=15KPa , Tsaturation
Pressure outlet = 30KPa ,Tsaturation
operating condition 0
wall,
axisymetric

explicit, second-order, courant number set to 0,5, iteration 25000


https://i.postimg.cc/T1yCSDXP/579371.jpg

I try to use implicit as a method but it is fly high to the floating point
when I try default courant number,the graphic doesn't smooth

my meshing set up :
orthogonal minimum 0,8
average 0,85

skewness max 0,3

does my set up is right?
why it doesn't want to convergence? I really confuse
thank you so much