CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   Sliding mesh vs MRF in axial turbine simulation (http://www.cfd-online.com/Forums/fluent/49294-sliding-mesh-vs-mrf-axial-turbine-simulation.html)

Vito September 18, 2008 18:36

Sliding mesh vs MRF in axial turbine simulation
 
Hello folk, I'm a student and I'm actually dealing with a simulation for estimating the torque in an axial turbine. The turbine could have different blade shapes, and I would evaluate the torque for each of them. The turbine has 20 mm diameter and 8 blades, while the medium is water. The mesh has been generated by Gambit, using the turbo plugin also. In addition to the volumes surrounding the blade I have 2 volumes more: one at the inlet and one at the outlet of the turbine, which have got a considerable lenght. According to the volumes related to the turbine, the inlet and outlet are modelled for 1/8 of the diameter. I created interfaces between the inlet-blade_volume and the blade_volume-outlet. In Fluent I tried to perform analisys with sliding mesh and MRF, leaving the boundaries, solver and other parameter the same for both simulation. The simulations converges in both case, but when I get the torque from turbo report panel, I obtain values which are considerable different. A relative error between the calculated torque in MRF and the calculated torque in sliding mesh is more than 55%. Is it normal? Which is you best suggestion for this kind on simulation? Thanks Vito

Vito September 21, 2008 09:04

Re: Sliding mesh vs MRF in axial turbine simulatio
 
Does anybody have experience with such problems?

emreg December 20, 2011 15:02

do you have any parts deters the flow?

than try TRANSIENT + SLIDING MESH ...

if not, so STEADY+MRF

shenheng86 December 21, 2011 04:57

Quote:

Originally Posted by emreg (Post 336512)
do you have any parts deters the flow?

than try TRANSIENT + SLIDING MESH ...

if not, so STEADY+MRF

:mad::mad::mad::mad::o:o


All times are GMT -4. The time now is 07:55.