[cheap_person]

Hi there,

I'am doing a simulation of assembly of centrifugal compressor (Impeller + diffuser)

Project schematic:
https://innovationspace.ansys.com/fo...8-mceclip0.png

when i run the simulation. it's been several times. Exactly on 50th iteration i get this error.
the residual graph:
https://innovationspace.ansys.com/fo...3-mceclip1.png

I'm using Ansys 2024 student version

I've already been through this forum. but, couldn't fine solution.
ERROR #004100018 has occurred in subroutine FINMES.

[Opaque]

Originally Posted by cheap_person

Hi there,

I'am doing a simulation of assembly of centrifugal compressor (Impeller + diffuser)

Project schematic:
https://innovationspace.ansys.com/fo...8-mceclip0.png

when i run the simulation. it's been several times. Exactly on 50th iteration i get this error.
the residual graph:
https://innovationspace.ansys.com/fo...3-mceclip1.png

I'm using Ansys 2024 student version

I've already been through this forum. but, couldn't fine solution.
ERROR #004100018 has occurred in subroutine FINMES.

I am puzzled. You are modeling a centrifugal compressor w/o solving the energy equation? Very likely you have chosen "Air at 25C" as a material, and that is an incompressible material.

Your setup is incorrect based on your goals.

[cheap_person]

Originally Posted by Opaque

I am puzzled. You are modeling a centrifugal compressor w/o solving the energy equation? Very likely you have chosen "Air at 25C" as a material, and that is an incompressible material.

Your setup is incorrect based on your goals.

Thank you so much opaque. this solution exactly worked the way it should be.

but, when i am trying to run the simulation in transient, it again shows the same error. I've posted the problem on cfd online forum. The link is given below.

Click here

Before redirect there, i want to know:
1. Why this error occurs, what is the acctual reason?
2. How can we reduce the chances of countering this error?

[Opaque]

Originally Posted by cheap_person

Thank you so much opaque. this solution exactly worked the way it should be.

but, when i am trying to run the simulation in transient, it again shows the same error. I've posted the problem on cfd online forum. The link is given below.

Click here

Before redirect there, i want to know:
1. Why this error occurs, what is the acctual reason?
2. How can we reduce the chances of countering this error?

Have you done the Transient Blade Row tutorials?

The setup you described in the MainForum has nothing to do with this one. This one you are not solving the energy equation (likely Air at 25C), the one in the MainForum uses "Air Ideal Gas" and it solves the energy equation. There is a HUGE difference between both models regardless if it is steady state or transient.

On top of the above, you are using the Time Transformation pitch change model and you are not showing its diagnostics. There is a set of specific guidelines on how to best run that model. Did you read the documentation for such guidelines?

You need to provide more information and show a bit more diagnostics for anyone to be able to provide you with meaningful feedback.

[cheap_person]

Originally Posted by Opaque

I am puzzled. You are modeling a centrifugal compressor w/o solving the energy equation? Very likely you have chosen "Air at 25C" as a material, and that is an incompressible material.

Your setup is incorrect based on your goals.

Sir, again I'm getting the same error.
even this time I made sure that I turned energy option on and fluid is ideal air.


image link: click here

[ghorrocks]

Have you checked the basic stuff? See FAQ: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

[cheap_person]

Originally Posted by ghorrocks

Have you checked the basic stuff? See FAQ: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

yes sir! I've been through this page before.

Even I performed couple of similar simulations successfully.
This time also, I'm not doing anything different, just copy pasting the values except one thing.

the thing is, using expression for pressure {inlet & outlet} and for speed.

I'm doing turbo machinery in cfx using turbo mode.

Sending positive vibes...!
cheap person.

[cheap_person]

Originally Posted by ghorrocks

Have you checked the basic stuff? See FAQ: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

I made it, ghorrocks sir!!!

the issue was coming due to wrong unit in expression.
my desired boundary condition is 60,000 rpm
but I was putting rad per sec unit with same value.
which leads to creation of extremely wrong physics.

now, I can run the simulation successfully.

thank you so much for your reply.
I warmly appreciate it sir!

sending cheering vibes...!
cheap person.

[ghorrocks]

Yes, well done.

That mistake was point 1 in the FAQ: "Is the physics of the simulation set up correctly?", a very common problem and too often overlooked.

[cheap_person]

Originally Posted by ghorrocks

Yes, well done.

That mistake was point 1 in the FAQ: "Is the physics of the simulation set up correctly?", a very common problem and too often overlooked.

sir please help!!!
i can't create new threat to ask my new doubts

it is showing

Forbidden
You don't have permission to access /Forums/newthread.php on this server.

[ghorrocks]

I cannot see anything in your profile which would stop you from starting a new thread. Are you trying to start a new thread from the CFX main page (https://www.cfd-online.com/Forums/cfx/)? The new thread button should work on that page.

[cheap_person]

Originally Posted by ghorrocks

I cannot see anything in your profile which would stop you from starting a new thread. Are you trying to start a new thread from the CFX main page (https://www.cfd-online.com/Forums/cfx/)? The new thread button should work on that page.

sir still!!! same error is showing up when I am trying to start a new thread from the link you have provided.

[ghorrocks]

I have sent a message about this to the forum owner. Hopefully they can resolve the issue soon.

[cheap_person]

Originally Posted by ghorrocks

I have sent a message about this to the forum owner. Hopefully they can resolve the issue soon.

while it is in process, i am forced to ask a new question here. Please let me, sir.

My new question is:

I'm trying to make a performance map by performing a cfd simulation of an impeller. It is performing using cfx, turbo mode.

in a you tube tutorial, negative sign is used to change the direction of rotation of the impeller.
But I am using and expression (speed, as an input parameter) to provide rpm, but i keep failing to get similar result with negative sign.

I tried the following combinations with negative sign:
1. - speed , 60000 (negative sign with expression speed while putting boundary condition, keeping value positive in input parameter)
2. speed , - 60000 (positive sign with expression speed while putting boundary condition, keeping value negative in input parameter)

But the arrow of the direction in pre-processing doesn't change.

Problem: Now I am unable to provide the correct direction of rotation to my impeller. It is rotating in opposite direction.
What is the solution?

sending positive vibes...!
cheap person

[cheap_person]

Originally Posted by ghorrocks

I have sent a message about this to the forum owner. Hopefully they can resolve the issue soon.

sir, please do not answer on this thread, issue solved!!!

actually i was sharing you tube link, i think that was restricting me to start a new thread.

Thank you so much for your support and efforts.
It means to me a lot.

sending warm vibes...!!!
cheap person