Vertical Axis Turbine Simulation

dalecooper · July 24, 2013, 07:51

Hello,

I have been doing some simulations with vertical axis turbines in Fluent. In order to achieve good results I have tried using the Inflation option in Ansys Meshing module around the different airfoils in the turbine. But I found a problem in Fluent that says: 'Divergence detected in AMG solver'. When I disable the Inflation option the problem disappears.

I have tried different meshing methods as quadrilaterals and triangles as well as refining the mesh using sphere of influence around every airfoil, but still I haven't found a proper solution to the divergence error.

Thanks in advance and best regards.

vasava · July 24, 2013, 08:42

Are you working with dynamic mesh or moving frame of reference?

dalecooper · July 24, 2013, 08:57

Quote:

Originally Posted by vasava

Are you working with dynamic mesh or moving frame of reference?

I'm working with sliding mesh techique. I have defined two interfaces to separate the rotating airfoils zone and the non moving mesh zones of my domain.

I have obtained some good results with the quad mesh, but when I use the triangle mesh the results are completely different and the computational time increases too much.

vasava · July 24, 2013, 09:53

The divergence message is because the pressure distribution is not correctly predicted.

You can check the pressure distribution and check if there is abnormal pressure distribution in some region. You can improve or refine mesh in that region.

If the pressure distribution is ok then you can lower the under relaxation factor for few iterations until the pressure is back to normal.

July 24, 2013, 07:51	Vertical Axis Turbine Simulation	#1
dalecooper New Member dalecooper Join Date: Jul 2012 Posts: 10 Rep Power: 14	Hello, I have been doing some simulations with vertical axis turbines in Fluent. In order to achieve good results I have tried using the Inflation option in Ansys Meshing module around the different airfoils in the turbine. But I found a problem in Fluent that says: 'Divergence detected in AMG solver'. When I disable the Inflation option the problem disappears. I have tried different meshing methods as quadrilaterals and triangles as well as refining the mesh using sphere of influence around every airfoil, but still I haven't found a proper solution to the divergence error. Thanks in advance and best regards.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
High torque coefficient Cm for Vertical Axis Wind Turbine (VAWT)	tony00	FLUENT	11	July 23, 2018 07:13
Wind turbine simulation problem	sanchovg2	STAR-CCM+	12	March 5, 2013 05:18
Vertical axis wind turbine	DrBidden	FloEFD, FloWorks & FloTHERM	4	December 21, 2012 21:50
vertical axis wind turbine: Steady State? Chart?	Jbc	ANSYS	0	September 5, 2012 18:34
Simulation of turbine cascade in CFX.	Jonas Pedro Caumo	CFX	0	December 9, 2006 14:54

July 24, 2013, 08:42		#2
vasava Senior Member Paritosh Vasava Join Date: Oct 2012 Location: Lappeenranta, Finland Posts: 732 Rep Power: 23	Are you working with dynamic mesh or moving frame of reference?

July 24, 2013, 09:53		#4
vasava Senior Member Paritosh Vasava Join Date: Oct 2012 Location: Lappeenranta, Finland Posts: 732 Rep Power: 23	The divergence message is because the pressure distribution is not correctly predicted. You can check the pressure distribution and check if there is abnormal pressure distribution in some region. You can improve or refine mesh in that region. If the pressure distribution is ok then you can lower the under relaxation factor for few iterations until the pressure is back to normal.