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LaBelleMiguelle
Posts: 16
Registered: ‎04-07-2014
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HELP-"The Analysis has stopped because the Solver has stopped unexpectedly"

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04-11-2014 03:30 AM

"The Analysis has stopped because the Solver has stopped unexpectedly"

I keep getting this message. I know I am new to cfd software but I really need some help

 

Hi, I am beyond panicked. I'm using Simulation CFD and the solver keeps crashing everytime before I can use it. Please please help. I don't know if there is something wrong with my model. I will send whatever files you need to help. This is due today. Please help

I don't even know which way I'm supposed to apply the volume, I chose to fill the void but now I'm not sure. I'm supposed to be modelling the drag and lift force on a ducted marine current .

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wildej
Posts: 937
Registered: ‎08-25-2011

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-11-2014 03:39 AM in reply to: LaBelleMiguelle

Hi,

 

I can try to help, short timeframe!

 

  1. You need a far longer inlet and outlet (5x dia is a general rule). Add an extruded cuboid in CAD to each side, using the inner edge of the shroud. Leave the inner section hollow and sealed, CFD will fill it automatically
  2. Are the blades meant to be rotating? Hope not, this is not likely to be a single day analysis :smileyhappy:
  3. You can suppress all solids from the mesh, at least the outer ones
  4. Ensure that the file is held on a local HDD, that will cause this error

Thanks,

Jon

 

P.S.  I was looking at attempt 2



Jon Wilde
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Contributor
LaBelleMiguelle
Posts: 16
Registered: ‎04-07-2014

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-11-2014 03:46 AM in reply to: wildej

Oh thank you so much, I'll fix the inlet and outlet issues.
Yes the blades are meant to be rotating but I don't know how, I tried using the motion tab but when I went to preview, nothing happened. I am supposed to optimise the performance of a marine current turbine by varying multiple parameters. I chose to vary the blade type and the angle of attack. I have no idea what output I should be looking for as I have never ever used cfd software before but I am definitely willing to learn.

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wildej
Posts: 937
Registered: ‎08-25-2011

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-11-2014 03:53 AM in reply to: LaBelleMiguelle

No worries.

 

OK, this is not a study you are going to be able to run in one day. 

 

You need a rotating region around the fan - check out the fan/pump guide.

There it lots on Autodesk Knowledge Network also.

 

Thanks,

Jon



Jon Wilde
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Contributor
LaBelleMiguelle
Posts: 16
Registered: ‎04-07-2014

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-11-2014 05:23 AM in reply to: wildej

Hey, I'm still getting the same message.

I added the extrusion, I noticed the element count was reduce but I am still getting the same error. I'm truly lost

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wildej
Posts: 937
Registered: ‎08-25-2011

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-11-2014 05:35 AM in reply to: LaBelleMiguelle

Well for one you have suppressed the fluid from the mesh :smileyhappy:

The size is spot on though.

 

There is still no rotating region (RR)  around the impeller, this is what you need to cause the rotation. This will need to be drawn in CAD, it needs to encompass the impeller and the OD should be 1/2 way between the tips and the solid surfaces of the wall. Same goes for the surfaces either end of the axis.

 

Once you have this, give everything a 0.5 mesh refinement, good starting point for this model.

Then ensure the outer surfaces of the RR have a uniform mesh, as they will be passing past the static elements of the water.

 

This will need to be run transiently, all the instructions are in the link I sent before.

 

Thanks,

Jon



Jon Wilde
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Contributor
LaBelleMiguelle
Posts: 16
Registered: ‎04-07-2014

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-12-2014 08:15 PM in reply to: wildej

Hi Jon,

 

Me again. I am getting the same error message. I created the rotating region. I made it uniform. It's not touching any solid surfaces, net even the axis infront and behind. I set the mesh refinement at 0.5 but the number of elements was well over 4 million. I assumed this was the cause of the error so I decided to leave the refinement as one for the fluid. I'm not sure what else to do. I really tried to figure it out. I double checked the bodies, I hope that I haven't confused them yet again but they, as well, seem correct. Please any extra help would be appreciated. And I went through every thing.

 

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wildej
Posts: 937
Registered: ‎08-25-2011

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-14-2014 12:41 AM in reply to: LaBelleMiguelle

Hi Kaye,

 

  • Your Rotating Region is a square - it needs to be a cylinder, which will rotate
  • You can suppress the rotor from the analysis
  • I would say you are going to need a smaller timestep, less than 1s to get it moving, then you can stop it and increase the value later. If his value is too large, you will likely see divergence
  • I would use ADV5, rather than 2 (Advection Scheme)
  • I am not sure if an '@' symbol in the name might cause an issue, worth mentioning just incase


Jon Wilde
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Contributor
LaBelleMiguelle
Posts: 16
Registered: ‎04-07-2014

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-14-2014 01:45 AM in reply to: wildej

Okay, I changed everything as you said and I'm still getting the same warning message. I'm really stumped on this one. 

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wildej
Posts: 937
Registered: ‎08-25-2011

Re: HELP-"The Analysis has stopped because the Solver has stopped unexpecte

04-14-2014 01:54 AM in reply to: LaBelleMiguelle

Hi Kaye,

 

It is running fine here, although the mesh is too coarse.

Are you running from a local drive?

 

Mesh.png



Jon Wilde
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