Sphere in the oil

General Questions
1

Hi to All
Can i simulate the temperature a very hot sphere (200° C) in (immersed) the oil, with an ambient temperature of 20° C? If yes, can you list the steps?
Thank you very much
Giovanni Di Maria

2

Yes, check this recent video with a similar case:

Oil can be simulated as convective film load with a sink temperature of 20 °C and proper film coefficient. You will also have to assign the initial temperature of 200 °C to the sphere. As you can see in the video, there’s even an approximate analytical solution based on the lumped capacitance method.

3

Fantastic.
Thank you very much for your Help
Giovanni

1 Like
4

HI
I have simulated a resistor of 200 Watt in the oil.
I don’t know if the results are correct.
I have created a little PDF document, with some steps, but i don’t know to attach it here.

image
image713×604 126 KB

Cheers
Giovanni

5

This is in transparency.

image
image742×610 111 KB

Giovanni

6

You can add .zip files so .pdf can be shared this way. Or you could host it somewhere and paste the link here.

Oil is simulated as a volume ? Did you try with convection load, as discussed before? The temperatures in your results are very high.

7

Yes, i have simulated your previous solution, it is more realistic.

image
image985×735 91.8 KB

This is the attachment, where oil is simulated as volume.
But i think that i am wrong in the numeric parameters…

olio03.zip (1.9 MB)

Cheer
Giovanni

8

Maybe 200 W is too much. I’m not an electrical engineer so I don’t have any experience with stuff like that but 200 W seems like quite a lot of power. Try running transient analysis to see how long it takes to reach these temperatures.

Just to make your workflow easier:

  • you don’t have to define surfaces manually, they can be created when defining contact pairs
  • you can use the Search Contact Pairs tool to automatically apply contacts

Actually, I would use tie constraints instead of contact pairs in this case (unless you know the value of gap conductance that should be used here).

9

HI.
Thank you very much.

  • I have used Search Contact Pairs tool: simply fantastic.
    So I have used Tie Constraints, the results is similar…
    I think it is correct, becouse 200 W is very much.

Thank you very very much
Giovanni