How can you do a thermal simulation of a power transformer in altair flux student version?

Hello Iñigo Izaguirre,

I did not understand, how you are getting only one temperature. Flux gives a distribution of temperature along the faces or volumes.

Please check the "Induction heating" example in Technical tutorials for transient thermal and other examples we have in thermal analysis to get an idea on how to setup and run the simulation. 

Thank you,

Lavanya

Can you please elaborate on getting one exact temperature?

Hello Lavanya,

I put here attached the model if you want to have a look. Thank you 

Hello Iñigo Izaguirre,

The definition of boundary conditions are not correct. That is why, Flux is not showing any temperature distribution.

Under Boundary conditions on Faces, you should define thermal exchanges like radiation or convection and assign their heat transfer coefficients. With this assignment, Flux will understand that there is heat that is being radiated through fluid medium (air in your case).

After providing the information of thermal exchanges, below is the temperature distribution in the model.

I am attaching the model for your reference. Let me know, if you have any questions.

Thank you,

Lavanya

Hello thanks for your solution and your time but I can not open it. I get this error every time I try.

Is a newer version program

Hello Iñigo Izaguirre,

I have recreated in the model in Flux 2021.0 version. You should be able to open the attached model now.

To open the files of advanced version in lower version, you need to edit first lines in the python files of model using editor which reads hex format.

Thank you,

Lavanya

sorry but i have the same problem now.Where is the new model? I had downloaded the same I think.

can you attached again?

I have the same error.

Hello Iñigo Izaguirre,

I have recreated in the model in Flux 2021.0 version. You should be able to open the attached model now.

To open the files of advanced version in lower version, you need to edit first lines in the python files of model using editor which reads hex format.

Thank you,

Lavanya

I think you forgot putting the model attached I dont see anything

Here is the file. Please check this one.

Here is the file. Please check this one.

Yes now I can open it. Thank you!

At the simulation now I dont understand the results. Why increases the temperature so high with that little losses. How can I fix this? What is the purpose of tha cutting center face

I have used a random number for heat transfer coefficient. You need to put correct value of coefficient to see the actual temperatures in model. 

The reason for cutting the center face is to see the temperature distribution. This will not be visible from outside when isovalues of temperature are plotted.

I have used a random number for heat transfer coefficient. You need to put correct value of coefficient to see the actual temperatures in model. 

The reason for cutting the center face is to see the temperature distribution. This will not be visible from outside when isovalues of temperature are plotted.

So I understand that the cut shows the temperature in 2D no?

So I understand that the cut shows the temperature in 2D no?

Yes. That is correct.

Yes. That is correct.

And how I can view 3D tenperature distribution?

Hello, 

I have put an air h coefficient of 15 (W/m2.K) but I obtain too big results again. Is there something left to set up?

I think face settings are okay but I dont understand how is possible to get that high temperatures with 40 and 15 W of thermal source in W in the core and the windings. 

Do I have to define the air volume region as inactive?

No, you should not define air volume region as inactive.

Two reasons for such high temperatures are :

- Heat transfer coefficient used on faces of airbox

- Thermal conductivity of air that is surrounding the transformer

I have used 0.025 W/mK for thermal conductivity of air. For natural convection, thermal conductivity ranges from 0.025 W/mK to 25 W/mK

If you have forced air cooling, the thermal conductivity of air ranges from 5 W/mK to 100 W/mK.

If you change the thermal conductivity of air, you should see lower temperatures in the model.

No, you should not define air volume region as inactive.

Two reasons for such high temperatures are :

- Heat transfer coefficient used on faces of airbox

- Thermal conductivity of air that is surrounding the transformer

I have used 0.025 W/mK for thermal conductivity of air. For natural convection, thermal conductivity ranges from 0.025 W/mK to 25 W/mK

If you have forced air cooling, the thermal conductivity of air ranges from 5 W/mK to 100 W/mK.

If you change the thermal conductivity of air, you should see lower temperatures in the model.

 

Please check the attached model with updated thermal conductivity.

Ok thank you! I think this temperature is has more sense. It probably not exactly correct but is a step forward. 

After this i was wondering if there is any way to obtain the average heating value of the different elements of the transformer. I mean how many average tenperature has increase the transformer.

Thank you 

Iñigo

Ok thank you! I think this temperature is has more sense. It probably not exactly correct but is a step forward. 

After this i was wondering if there is any way to obtain the average heating value of the different elements of the transformer. I mean how many average tenperature has increase the transformer.

 

Thank you 

Iñigo

Yes you can create a sensor on Transformer with operation of average temperature.

To create a sensor, Under data tree<Parameter/Quantity<Sensor<Right click, Select New<Create a sensor as below.

Then Evaluate sensor and display the curve of average temperature.

Hello,

Thank you for the help I am going forward in the simulation. Now I am trying to set up correctly the convection and radiation values. I put all the values but I dont know whst to put in the absortion coefficient value I was wondering if you have any advice when putting this values because I understand this values are not constant in reality. 

Also I have a question because in the model my transformer core is set like one piece(not laminated) but in reality this core is a laminated non magnetic core. I havebt seen the option to set it like that and I dont know how much may this affect to the heating results of any transformer.