Momentum source
 

Hi all,

I have a question about momentum source. The model i created is just a cylindrical pipe with 10 mm diameter and 50 mm long, the fluid flow along the tube is sucrose with density is equal to 1324.7 kg/m^3 and dinamic viscosity is 0.23677 mPa.s

The flow at the portion of inlet is set to inlet boundary condition, normal velocity 0.005 m/s. I set the opposite side of the inlet to outlet BC., average relative static temperature 0.0 Pa and set the tube wall to exteria wall , no slip condition. There are a thin concentric cylindrical subdomain (0.2mm thick) in the middle length of the tube. I specify the momentum source along the direction of the tube length to 5 kg/m^2s^2 .

I expect to see a changeing of volocity profile effected by momentum add but it's not. There's no difference of result between no momentum add and 5 kg/m^2s^2 neither nor 10 30 and 100 kg/m^2s^2 momentum add. All of momementum add value i used give the same result.

What's wrong?Did I set the wrong BC? Anybody who have an idea give me a suggestion please