CPVC Model Geyser

Visit http://mypage.iusb.edu/~brdavis/GeyserModel.html for some more details on these models, including parts lists. These models function in a very similar fashion to real geysers (& nothing like the "Diet Coke & Mentos" versions), with superheated water flashing to steam and driving an eruption. There are some major differences - these models are so small, convection is very difficult. But they are *much* closer in their operation than most "cold gas" geysers.

Category:

Education

Tags:

• model geyser
• science fair model
• plumbing
• geyser
• yellowstone
• CPVC

[bubbellz]

hey brdavis; how much time does it take for a model gyser to erupt?

[brdavis5]

That depends. There are two times that are important: the duration (how long it actively erupts for) and the interval (the time between eruptions). The interval depends on how fast you heat it (the faster, the shorter the interval) and the depth (the deeper, the longer the interval), among lots of other things. I've made geysers that have intervals from a minute or 2 to 20 or 30 minutes (and at least one with an interval of about 6 seconds).

[bubbellz]

thanks :) Just one more question... Does the diameter of the glass tube affect the interval? you rule , thanks alot ^^

[brdavis5]

My *guess* (in other words, I've not tested this), is it would effect it little or none for small diameters. Most of these erupt from the bottom - in other words, when the water at the bottom hits boiling, it ejects water from the conduit, lowering the pressure and initiating an eruption. Conduit diameter could effect this in two ways. A large diameter conduit could make the system less efficient at cooling during an eruption (making for a shorter interval), or...

[brdavis5]

...a large enough conduit can have convection within it, withdrawing warm water from the base & exchanging that with cooler water from above, thereby making it longer between eruptions (instead of heating just the base, you have to heat a significant part of the conduit as well). The 2nd I've seen when the conduit approaches 2" in diameter, the first I've not seen direct evidence for.

But in either case, the effect seems small compared to conduit depth and heat input.

[NeXTSTORMING]

Excellent material!!

I was really amazed by the number of variations you have created to experiment with. I've seen the video twice and the whole "trip" reminded me a John Barton's quote I read some time ago: "The point of an experiment is not to arrive at a predetermined result -prove or disprove something- but to deliver a poem that reveals much about the process taken"...

NeXTSTORM

[brdavis5]

Or to put it another way: "The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, 'hmm... that's funny...'" (generally attributed to Asimov).

[brdavis5]

As to supplies... other than the flasks, and a few glass segments, just about everything you see was bought at local toy stores (or LEGO on-line) or hardware stores. Although the people at Lowe's look at me funny and hide every time they see me head for the plumbing section.

[brdavis5]

Thanks! One of the models shown in the "rapid slide show" actually does refill from a reservoir, and dumps to a waste container (notice in the blue basin how there's a 2nd, offset "vent"? That's the drain in some models). The problem was the amount of time it took to heat honestly cold water put a limit on how many cycles could usefully be observed, so I ended up with a recycling model for thermal considerations. I do have ways of changing the refill rate (flowback rate).