transonic compressor Convrgce pb with transient ..

Noureddine

Hi,

I would excute a transient simulation of an isolated transonic Rotor 37 using ANSYS CFX 11 with rotation along one pitch, i did not have any problem to get results for steady fluid flow but i could not converge with transient any way.

However, I noticed that the value of pitches displayed by the solver doesnt correspond to that i specified.

my setup is as fellow :

- Rotor 37 design speed = 17188.7 rpm = 1800 [rad/s]

- 36 blades ===> 1 pitch = 2*pi/36 = 2*3.1416/36 = 0.1745333 [rad]

- total time to rotate along one pitch = 0.1745333/1800 = 9.7e-5 [s]

- if i choose 100 time steps ===> DT = 9.7e-5/100 = 9.7e-7 [s].

I should see in each time step an increase of pitches by 0.01, but it is not the case !!!!!!

what it can be the problem ?????

any advice is very welcome.

Regards,