rushton turbine + MRF impeller tip higher speed than physically possible?
 

hi all,

i am currently simulating
- a 6 blade rushton impeller with 4 baffles in a tank/mixing vessel
with following specs:
- rotor/stator: MRF -> 14 rps -> Re=40.000 turbulent
- U_tip = PI*D*N = 2.24 m/s

however, when i normalize the tangential velocity, i.e. U_tangential/U_tip, the max value i get is larger than 1 for the impeller tip (see attached file).

the results i saw from publications don't have such values, does it even make sense that the impeller tip is faster than the theoretical value?

thanks for any tips and hints

Hi geth, how did you calculate the tip speed, and radial and tangential velocity of the impeller? I am also in the same boat rn. TIA