[Geysers] Re: Model Geysers

[Davis, Brian L.]

Hello Demetri; you and I had some correspondences on YouTube if I recall about my geyser animation. Welcome.

> Specifically I will attempt to model the basic relationship
> between Turban and Grand geysers.

I'd very strongly suggest you try to find a copy of this paper:

Cross, Jeff, "Changes in the Minor Activity of Geysers Prior to an Eruption", GOSA TRansactions, V10 (2008), pp88-95

Not only is it a great description of the eruption, but it puts forward a very plausible mechanism (heating at two different points in a branched conduit). Jeff has also experimented with a single-chamber system with two vents, with the junction located both high and low in the system, and he notes the differences in the behavior.

> If anybody though has experimented with multiple model geysers with
> subsurface connections to each other, it would be really helpful if you
> could contact me with what you did and observed so I can have some
> background knowledge for my project.

I *really* need to write something up, or at least pop some stuff up on YouTube. I've done both multi-chamber, single vent systems, as well as multi-vent, multi-chamber systems, and I've used both the hot plate / borosilicate flask as a chamber, and an externally heated metal pipe (not as successfully; still working on it). My findings are similar to some of Jeff's but also some that seem to point to odder, different behaviors... but I'm not sure how much of this is due to problems with Taylor bubble flow in the small tubes I use (Jeff and his father use large diameter metal pipe: 8" or so. I'm using 1/2", 3/4", and 1" CPVC pipe with some glass segments if I want to see bubble propagation within the conduit).

I have recently set up a system that was a "U tube", with one leg having a heated 1" galvanized steel pipe below a pool for producing eruptions, and a second leg running from a deeper "cistern" that connected with the first below the heated segment. The result did not have impressive eruptions, (I suspect due to heat loss within the system, there being a lot of surface area the loose heat too), but it had very nice periodic discharge, with a concurrent draw-down of the cistern very much like how Grand's pool drops during a Turban eruption.

I just put some more pipe together today, to try to look at the effects of closed branched conduits and "thudding", as well as scaling up (using a 2 liter flask with perhaps a 3 meter 1" standpipe).

If anyone is curious about how to do this out of common plumbing supplies, I have finally put up a web page with building instructions (but no analysis as yet - my models are instrumented for temperature and pressure usually):

http://mypage.iusb.edu/~brdavis/GeyserModel.html

Near the bottom is a picture of a dual chamber, single vent system (reliably gives minors and majors, but not in a perfectly reproducible ratio).

> (last year's geyser, unconventional in its refill system
> to increase accuracy and height)
>
> http://www.youtube.com/watch?v=d1r0siDjL2M

I can see how refilling with a "cool" source might be more accurate (actually, I suspect any constant-temperature source would be OK... it's not like the groundwater recharging a geyser is likely to be at all cold by the time it hits the conduit). But how did this alter the height?

-- 
Brian Davis