How can I apply 1 Joule to a Body? (Understanding the Heat Source)

[ScientistRenzo]

Hello!

I would like to apply 1 total Joule to my cube. How can I do this?

I've discovered I don't understand "Heat Source". For example, when I apply Heat Source = 1, am I applying 1 Joule of energy/heat, continuously?
If that is what I am doing, then how can I accurately apply 1 total Joule to my Body?
Is the Heat Source a rate? 1 J / s?

I guess a steady state simulation will just keep applying 1 J somehow until the block hits some limit, the steady state solution if it exists
and a transient solution will apply 1 Joule somehow over the window I choose.

Can you share what you understand about the Heat Source option and how I can do what I want to

Thanks a million

[ScientistRenzo]

I would also like to know, about what settings/conditions I should choose to set up an ideal simulation.

I want to apply 1 Joule of heat to a cube of water that weighs 1 kg.
Thus I have applied 1 Grey = 1 J / kg.
The expected temperature rise everywhere in the cube will be 0.25 mK, or 0.00025 K.

First I need to know how to apply 1 Joule to my cube.
Then I need to know how I can make this simulation more ideal for this test.

I've tested this with the cube having 0.95 Idealized Radiation Emissivity: ParaView shows circular temperature-varying gradients on the surfaces and inside of the cube https://imgur.com/a/J012SWu

Why? (Simply.)
I estimate this is due to the radiation. In contrast to these results, I would like to see if I can get ideal results, where the temperature is uniform everywhere.

Help?

Thank you

Files in case you want them
https://drive.google.com/drive/folders/ ... sp=sharing

[kevinarden]

The manual says the heat source is joule per mass so I made the mass = 1, cube is .1x.1x.1 density 1000 mass = 1
Q= c m Delta T
set heat source to 1
c = 4184
Delta T = 0.00024

initial condition zero, external temperature zeror

I used Heat Flux BC and Radiation Ideal same answer
Delta T elmer = 17.5

[kevinarden]

Changed c=1, m=1, Q =1 (assuming heat source is joule/mass)

Delta T is still 17.5

[ScientistRenzo]

Thanks!
It turns out Heat Source units are W/kg = (J/s)/kg

[kevinarden]

When i run it in transient for 1 second I get a delta T of 0.00024 which is the expected answer
Q= c m Delta T
set heat source to 1
c = 4184
Delta T = 0.00024

initial condition zero, external temperature zero

[ScientistRenzo]

I have posted a question that follows understanding the Heat Source viewtopic.php?f=7&t=7430&p=24797#p24797