Heat flux Question

[Kylar Smith]

A bit of a technical question, I'm messing around with heat flux equations so as to calculate sweet spots on some of my more complex builds. If I want to run around 300 mW/mm² and my heat flux for a coil is 4.28 mW/mm² per watt, how do I calculate this? I think I know but I just want to be sure. Thanks in advance for any help.

 

[T0mmy1977]

A bit of a technical question, I'm messing around with heat flux equations so as to calculate sweet spots on some of my more complex builds. If I want to run around 300 mW/mm² and my heat flux for a coil is 4.28 mW/mm² per watt, how do I calculate this? I think I know but I just want to be sure. Thanks in advance for any help.

I couldn't tell you, but maybe the coil calculator may help.

Coil wrapping | Steam Engine | free vaping calculators

 

[Ed Brown]

In physics they taught us that the units will point to how to do the math. The calculation is as follows:

300 mW/mm²
4.28 mW/mm²/W

300/4.28 = 70, mW/mm² in the top and bottom cancel, and W in the bottom of the bottom goes to the top. So it is 70W

 

[Ed Brown]

Just curious, where did the 4.28 mW/mm²/W come from? That would depend on the surface area of the coil. Did you calculate that, or is there a table somewhere where you got it for that particular coil?

 

[Kylar Smith]

Just curious, where did the 4.28 mW/mm²/W come from? That would depend on the surface area of the coil. Did you calculate that, or is there a table somewhere where you got it for that particular coil?

Thanks for that answer and conformation. It's what I had figured. I put together a coil wrapping spreadsheet based on Steam Engine's numbers to try and make my own Sweet Spot calculator. I've been trading coils and thought I would add "recommended wattage" to the package. Most of the starting numbers came from either spec sheets for individual wires or if I couldn't find that, Steam Engine.