Recent content by Yarbles

Thanks 256bits that's a lot of stuff to explore. I really appreciate you spending the time. And everyone else of course.

Does the pot side of the boundary layer go above boiling temp? The microwaved super-heated water example above suggests this might be possible, maybe while the water waits to nucleate? (note I know next to nothing about nucleation)

Ah, I don't actually want to make the solid surface hotter but I'm interested in what could/would make it hotter than boiling temp. Temperature gradient through the thickness is not something I need to consider. I appreciate your patience with my PF question (I'm assuming it doesn't stand for...

Post 6 states 'Water cannot be liquid above its boiling temp'. No mention of inner pot surface. Why would we ignore the possibility of superheating?

Not facetious at all Merlin3189. I mentioned bubbles causing insulation just as a possible cause for the delta between the heating surface and boiling point. I don;t want to consider solids added to the surface tho, just fluid mechanisms. Not sure what a 'PF' question is. The question/thread...

If I increase boiling point then won't the boiling surface increase in temperature until boiling begins again? At that point, if heat in (power of the burner) is unchanged then the rate of boiling (mass of steam created per second) should remain unchanged?

To be clear from here on out: I wish to know how much the temperature of the inside surface (solid surface that's in contact with the fluid) can differ from the current boiling temp of the fluid. More importantly, I'm trying to understand the mechanisms that can cause the temperature difference.

If I change the boiling temp will the boiling surface (is 'hot wall' a better term?) change by the same amount? I think I'd rather stay away from adding surface material (scale) to the mix for now. Thanks!

I was referring to correlations that give a delta between boiling surface temp (the solid surface) and boil temp.

Yes I'm interested in the temperature of the pot's surface and how much it can differ from boil temp. Sorry to be unclear.

What could I do to get my pot surface hotter than boiling temp? I've seen correlations for boiling heat transfer coefficient; do those only account for bubbles insulating boiling surfaces or other phenomena as well?

From intuition: As long as the surface is covered with water (no lingering/giant bubbles) then the surface should remain right at boiling temp. From other sources: Heat Transfer Coefficient is involved somehow. However, I'm interested in any phenomena that could influence the surface...

What determines the surface temperature inside a pot of boiling water, right over the heat source? Can it go much over boiling temp if the water's just gently boiling?

Im a little confused by most of that but 'air in the pipe' got me thinking. What effect would air have in my simplified pipe above?

Hi, To help me understand two phase cooling etc. I have some simplified heat pipe questions: If a sealed, vertical pipe, half filled with water has heat applied to its bottom half and the top half is held at 120C, is it safe to say that the inner surface of the bottom half of the pipe will also...