convergence of propeller blade velocity

dnb2289 · August 21, 2013, 07:35

hallo everyone!!
from last one month i have started working on fluent and my goal is to get convergence of propeller blade velocity.I have tried by changing controls from solver also but my solution is almost remain constant after 100 iterations and its not getting converged .so i need your help.so let me know how should i proceed now??

Thanks & Regards,
Vishal

A CFD free user · August 21, 2013, 15:09

Hello there
If there is no problem concerning the geometry (model and mesh quality) and boundary conditions, then you need to increase the velocity gradually. For instance, if you want to run a impeller with 200 rpm, then first start with 30 rpm and increase it 20 rpm step by step and in each step, try to get a converged solution. Be careful to apply right turbulence model as well.
Good luck

dnb2289 · August 22, 2013, 05:08

hallo ,
Thank you for reply and so now let me try this method and if i would have any problem then will let you know,

Best Regards,
Dharmesh

vasava · August 22, 2013, 05:41

Some questions:
1. What approach are you using? Moving frame of reference, dynamic mesh or something else?
2. Is your simulations steady-state or transient?
3. What makes you say 'my solution is almost remain constant after 100 iterations and its not getting converged'? Are you observing a particular quantity or Convergence graph?

Few pictures from your mesh and results would also help us help you.

dnb2289 · August 22, 2013, 07:18

Hallo Vasava,
Description of My task: I am working on propeller blades of helicopters and i have to get convergence of three types of blade inlet velocity and my approach is Absolute reference frame and my simulation is for steady state condition. and velocity and mass flowrate i set same in all three blades ,in one old wood blade i got convergence and in one blade after trying many times the convergence not coming near to criteria but its going up and up and in one blade convergence remain almost constant after 100 iterations ..My main goal is to get convergent solution of inlet velocity of all blades .i have checked mesh and everything and my supervisor also checked .I don't know how to take photo so tell me how can i click and send .

Thank you

Best regards,
vishal

August 21, 2013, 07:35	convergence of propeller blade velocity	#1
dnb2289 New Member vishal Join Date: Aug 2013 Posts: 3 Rep Power: 12	hallo everyone!! from last one month i have started working on fluent and my goal is to get convergence of propeller blade velocity.I have tried by changing controls from solver also but my solution is almost remain constant after 100 iterations and its not getting converged .so i need your help.so let me know how should i proceed now?? Thanks & Regards, Vishal

August 21, 2013, 15:09		#2
A CFD free user Senior Member A-A Azarafza Join Date: Jan 2013 Posts: 226 Rep Power: 14	Hello there If there is no problem concerning the geometry (model and mesh quality) and boundary conditions, then you need to increase the velocity gradually. For instance, if you want to run a impeller with 200 rpm, then first start with 30 rpm and increase it 20 rpm step by step and in each step, try to get a converged solution. Be careful to apply right turbulence model as well. Good luck __________________ Regard yours

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Force can not converge	colopolo	CFX	13	October 4, 2011 22:03
Reference Velocity Calculation & Convergence Problem	hasan_hzl	Main CFD Forum	0	January 29, 2011 13:42
Inlet Flow Velocity or pressure gradient - modeling of a Wind Turbine Blade case	LittleBart	Main CFD Forum	5	January 10, 2011 15:07
Ultra slow convergence velocity in the simulation	demigod	FLUENT	1	October 5, 2005 08:03
propeller rotating at zero inflow velocity	Ammu	FLUENT	1	July 23, 2005 13:36

August 22, 2013, 05:08		#3
dnb2289 New Member vishal Join Date: Aug 2013 Posts: 3 Rep Power: 12	hallo , Thank you for reply and so now let me try this method and if i would have any problem then will let you know, Best Regards, Dharmesh

August 22, 2013, 05:41		#4
vasava Senior Member Paritosh Vasava Join Date: Oct 2012 Location: Lappeenranta, Finland Posts: 732 Rep Power: 22	Some questions: 1. What approach are you using? Moving frame of reference, dynamic mesh or something else? 2. Is your simulations steady-state or transient? 3. What makes you say 'my solution is almost remain constant after 100 iterations and its not getting converged'? Are you observing a particular quantity or Convergence graph? Few pictures from your mesh and results would also help us help you.

August 22, 2013, 07:18		#5
dnb2289 New Member vishal Join Date: Aug 2013 Posts: 3 Rep Power: 12	Hallo Vasava, Description of My task: I am working on propeller blades of helicopters and i have to get convergence of three types of blade inlet velocity and my approach is Absolute reference frame and my simulation is for steady state condition. and velocity and mass flowrate i set same in all three blades ,in one old wood blade i got convergence and in one blade after trying many times the convergence not coming near to criteria but its going up and up and in one blade convergence remain almost constant after 100 iterations ..My main goal is to get convergent solution of inlet velocity of all blades .i have checked mesh and everything and my supervisor also checked .I don't know how to take photo so tell me how can i click and send . Thank you Best regards, vishal