AnsweredAssumed Answered

Marin Propeller simulation - Thrust results don't match ..

Question asked by Shar Fa on May 1, 2016
Latest reply on Jan 15, 2017 by Dave Bond

Hi guys!

 

I'm working on validating through flow simulation a known marine propeller with the following data:

600 RPM

V_water=1.4 m/s

Thrust is suppose to be around 23 [N] (calculated), with effic. > 0.7 for the very least.

 

Creating the model on solidworks i had the control of how to place the blades (their pitch) against the hub.

It was set as 50.5 deg at r/R=0.2 manually, and the simulation results show a symmetric velocity and pressure profile around the blades with this setting (as opposed to when I tried setting at different angle which either shown no symmetry or no high-low pressure profile above and behind the blade section view).

 

Problem is the results I get for the thrust and torque (too low as well) do not make sense.

Thrust is too low (around 1-3 [N] after full convergence) with a torque of approx. 1 [Nm] which gives a VERY bad efficiency rate (does not make sense).

Removing/Changing hub geometry has negligible effects (tried no hub, cylinder hub and the attached 'improved' hub adding 1 [N] compared to a goal of 23 [N])

Hub2_AntiCloclwiseBackFlow.png

Any guidance would be much appreciated

Thanks!

Outcomes