Heat transfer - SPCD multiple temperature

Lucia R

Hi,

I am doing a heat transfer analysis (transient) with OptiStruct and I want to apply a distribution of temperatures to a solid face.

I usually use TLOAD1 cards as DLOAD in the loadstep, and SPCD in the EXCITEID field of the TLOAD card.

I know how to apply SPCD constraints when the temperature is the same for all nodes of the face, but I have a .txt file with different temperature values of each node and I don't know how to proceed.

What is the procedure to solve this problem?

Thanks in advance!

Adriano A. Koga

You may try usong 'field' entity in the model browser.

You create a field and assign your txt file to it and then realize it in your mesh and it will find the closest nodes to aplly5 the field as temperature

Take a look at field documentation in the help.

Lucia R

Thanks for your answer!

I've follow your guidelines but when I realized the field and contour the temperatures, the values are 0 (see image below)

Do you know why temperatures are 0?

 

(in the .txt file the temperatures don't are 0)

<?xml version="1.0" encoding="UTF-8"?>

<?xml version="1.0" encoding="UTF-8"?>

Adriano A. Koga

are you sure your model dimensions/units are the same as the original txt file?

Sometimes the scale can give you some trouble.

 

Also, you have a mesh in your model, correct?

Lucia R

You were right! I had a problem with dimensions. 

Now that I have the field realized, what is the next step? 

I've tried to run Optistruct but in the results the temperatures of the field don`t appear, so I don't know if I have to include the field in the loadstep neither how to include it.

Thanks so much! 

Adriano A. Koga

Are you requesting the output of temperature and heat fluxes?

Lucia R

Yes

Adriano A. Koga

did your model run until the end or did you get any error?

Can you share your .out file?

Lucia R

The model runs until the end, but the temperatures field is not detected.

 

Here is my .out file

 

<?xml version="1.0" encoding="UTF-8"?>

Unable to find an attachment - read this blog

Adriano A. Koga

your model is big..it has a couple millions elements...but ok..just takes longer to run.

 

But i understand that you're running a thermal transient analysis, and you get your temperature fields from somewhre else, maybe CFD..

How do you want to use these temperatures in your transient run?

Do you want to apply them as initial conditions? or as imposed temperature curves?
 

For what i've seen you can calculate temperature, but maybe it is not what you expected. 

Lucia R

Yes, you are right. I want to use the temperatures as imposed temperatures in the thermal transient analysis, not as initial conditions.