Performing impeller analysis

[vyas.harsh.d]

Hello all,

I am trying to perform the analysis of impeller using AUTODESK CFD. But I am not getting a way how to perform simulation of impeller alone. Is it compulsorily required to have casing for it ?

[vyas.harsh.d]

Hello all,

I am trying to perform the analysis of impeller using AUTODESK CFD. But I am not getting a way how to perform simulation of impeller alone. Is it compulsorily required to have casing for it ?

[Jon.Wilde]

Hi,

It depends what you want to do, you can have it sitting in a large domain if you need to.

What are you trying to get from the analysis?

Thanks,

Jon

[Jon.Wilde]

Hi,

It depends what you want to do, you can have it sitting in a large domain if you need to.

What are you trying to get from the analysis?

Thanks,

Jon

[vyas.harsh.d]

Hello Jon,

Thank you for your response. Actually I want to compare flow rate in the impeller before underfiling and after underfiling. I want to see if there is any change in value of flow rate after underfiling the vanes of the impeller. I suppose it should increase slightly. So for it I want to define boundary condition as follows:
Pressure at suction eye as 0 atm and Pressure at discharge 1.7 atm. and full Rpm 1440 along Z axis
The result that we should get is flow rate after performing the simulation.

So Could you please guide on performing this type of case study in AUTODESK CFD.

I would appreciate your help.

Thank you

[vyas.harsh.d]

Hello Jon,

Thank you for your response. Actually I want to compare flow rate in the impeller before underfiling and after underfiling. I want to see if there is any change in value of flow rate after underfiling the vanes of the impeller. I suppose it should increase slightly. So for it I want to define boundary condition as follows:
Pressure at suction eye as 0 atm and Pressure at discharge 1.7 atm. and full Rpm 1440 along Z axis
The result that we should get is flow rate after performing the simulation.

So Could you please guide on performing this type of case study in AUTODESK CFD.

I would appreciate your help.

Thank you

[Jon.Wilde]

OK, understood. Why not make this comparison with it in a tube though, to keep things simple and faster?

Check out the webinar here as a starting point 🙂

[Jon.Wilde]

OK, understood. Why not make this comparison with it in a tube though, to keep things simple and faster?

Check out the webinar here as a starting point 🙂

[vyas.harsh.d]

Thank you for sharing the link to webinar. It was indeed a very good one to understand but it too had an casing. 

I am not getting clear with the term 'tube' could you please explain. what would be my outlet in that situation ?

Thank you.

[vyas.harsh.d]

Thank you for sharing the link to webinar. It was indeed a very good one to understand but it too had an casing. 

I am not getting clear with the term 'tube' could you please explain. what would be my outlet in that situation ?

Thank you.

[Jon.Wilde]

Hi,

No problem, glad it was useful! There is also this page, which sort of summarises it all.

You would essentially put the impeller in a tight fitting, cylindrical wind tunnel. Up stream you would have 5x diameters in length of fluid and 10x downstream. 

Does that make sense?

[Jon.Wilde]

Hi,

No problem, glad it was useful! There is also this page, which sort of summarises it all.

You would essentially put the impeller in a tight fitting, cylindrical wind tunnel. Up stream you would have 5x diameters in length of fluid and 10x downstream. 

Does that make sense?

[vyas.harsh.d]

Hello Jon,


  As per my understanding the wind tunnel you are suggesting should be as sketched below.

Impeller is between outlet and inlet fluid domain eliminating need for casing. Is it the right fluid domain assembly that you are conveying ?

If not please guide me.



Thank you for your time and help

[vyas.harsh.d]

Hello Jon,


  As per my understanding the wind tunnel you are suggesting should be as sketched below.

Impeller is between outlet and inlet fluid domain eliminating need for casing. Is it the right fluid domain assembly that you are conveying ?

If not please guide me.



Thank you for your time and help

[Jon.Wilde]

Hi,

Sure, something like that 🙂

Is the outlet size really smaller than the inlet? If so, this is perfect - just extend the outlet by about 2x what it is and you should be good to go!

Does the flow go in the directions suggested, much like a propeller?

[Jon.Wilde]

Hi,

Sure, something like that 🙂

Is the outlet size really smaller than the inlet? If so, this is perfect - just extend the outlet by about 2x what it is and you should be good to go!

Does the flow go in the directions suggested, much like a propeller?

[vyas.harsh.d]

Hello Jon,

I performed the analysis today and it ran successfully. Then I was trying to plot the H-Q curve as per the API by following below steps:

i) First clicking on Setup in Add-Ins tab. and It generates different scenarios with varying Flow rate in GPM.

ii) Then clicking on "Process Data" tab to get excel chart. but It is showing an error as " Section 'outlet 2' does not exist "

Could you please help me with it ?



-Thanks and Regards

Harsh Vyas

[vyas.harsh.d]

Hello Jon,

I performed the analysis today and it ran successfully. Then I was trying to plot the H-Q curve as per the API by following below steps:

i) First clicking on Setup in Add-Ins tab. and It generates different scenarios with varying Flow rate in GPM.

ii) Then clicking on "Process Data" tab to get excel chart. but It is showing an error as " Section 'outlet 2' does not exist "

Could you please help me with it ?



-Thanks and Regards

Harsh Vyas

[Jon.Wilde]

Hi,

Did you add the inlet and outlet to groups like the script says also?

[Jon.Wilde]

Hi,

Did you add the inlet and outlet to groups like the script says also?

[vyas.harsh.d]

Yes I already did but its showing the error which I mentioned.

[vyas.harsh.d]

Yes I already did but its showing the error which I mentioned.

[Jon.Wilde]

What version of CFD are you using? I wonder if it is compatible?

[Jon.Wilde]

What version of CFD are you using? I wonder if it is compatible?

[vyas.harsh.d]

Its AUTODESK SIMULATION CFD 2014

[vyas.harsh.d]

Its AUTODESK SIMULATION CFD 2014

[Jon.Wilde]

Then it should work I think.

Could you share a screenshot including the design study bar and the error you are getting?

Thanks,

Jon

[Jon.Wilde]

Then it should work I think.

Could you share a screenshot including the design study bar and the error you are getting?

Thanks,

Jon

[vyas.harsh.d]

Here is the screenshot.

[vyas.harsh.d]

Here is the screenshot.

[Jon.Wilde]

Hmmm, that does look OK to me. Maybe it is case sensitive? 

I have asked the guy who wrote the app to take a look at this thread and comment if he can 🙂

[Jon.Wilde]

Hmmm, that does look OK to me. Maybe it is case sensitive? 

I have asked the guy who wrote the app to take a look at this thread and comment if he can 🙂

[vyas.harsh.d]

Hello Jon,

I tried with the example given in webinar. Also I took care of case sensitive letters. Still I am getting the same error (Please find above screen shot). Let me know if you could help me with it.

Thanks and Regards,
Harsh Vyas

[vyas.harsh.d]

Hello Jon,

I tried with the example given in webinar. Also I took care of case sensitive letters. Still I am getting the same error (Please find above screen shot). Let me know if you could help me with it.

Thanks and Regards,
Harsh Vyas