Thursday, December 24, 2009

A merry Christmas flume.

More of the little prototype I'm working on, the lights in the background are in our front windows.  Peace and happiness to all.

Wednesday, December 16, 2009

The Emflume takes another step forward.

Could you use a small 2D flume to teach fluid mechanics to your engineering, stream ecology, and geoscience students?

I got this small prototype in working mode today.  We hope to build a version that would sit on the end of our Em2 models.

I should thank the amazing Steven Vogel for helping me with the design, which uses a propeller pump like his "swim tunnels" used for fish research.  It's a very efficient and interesting way to short-lift a lot of water.  The motor at upper left drives a shaft and propeller in a 3-inch duct.  Flow circulates clockwise.  Here you see it pumping around 1.5 cfs using only a couple of amps and making very little noise.

Having the fluid mechanics part nearly done, we have to integrate mass production, safety issues, economics, university science curriculum, and a dozen more things to get to a final design.

The middle photo shows hydraulic jump over a broad wier; at bottom you see a flash photo I took of the sheet aluminum propeller we made running at around 800 rpm.

Saturday, December 12, 2009

Minnesota geomorphology trip, part two.

After visiting the St. Anthony Falls Hydraulic Laboratory, Kate and I met with Peder Thompson, who develops exhibits for the Science Museum of Minnesota.  Peder has done some amazing exhibits on hydraulics, hydrology, and atmospheric phenomenon for SMM, perhaps the best in the world.

Here you can see him with an incredible hydraulics bench display he's working on.  That's a fully operational pump he scratch built from acrylic.  Peter and I've talked a lot about modeling rivers for museum work.

Here you see a huge interactive wave simulation tank--the floor has many cool interactive exhibits, my scientist wife and I learned a few things in the physics and biology sections!  Visit if you can, and plan to spend some time there.

Minnesota geomorphology trip, part one.

Two weeks ago Kate (my spouse and silent partner in LRRD) and I took a working vacation in Minnesota, first visiting the St. Anthony Falls Hydraulic Laboratory.  Karen Campbell was kind enough to give us a tour.

This is a fantastic facility.  Built in the 1930's, it uses a natural drop in the Mississippi River (geomorph here, rich history of the area here) to provide head for the lab.  Researchers can get hundreds of cfs without pumping.  It's the only facility of its kind in the world.

Here you see Karen and Kate overlook SAFL's new Outdoor Stream Lab, an experimental channel built last year.  OSL link: 

We were also able to see the lab's famous Jurassic Tank and other research facilities.

The Lab has done a lot of work on scale modeling, most famously of a couple of dam removals.  Video from National Geographic here.  Here Karen shows Kate a model of a model; a small representation of the Elwha Dam removal.

We'll be collaborating with Karen on an upcoming NSF proposal to develop curriculum for river models.  I'm very grateful to her for working with us on that.

The last couple of photos show an old flume I'm pretty sure is featured in some of the first educational films on fluid mechanics.  (I wish SAFL/UMN would put these online and not require DVD orders.)  Quite a steampunk contraption.  Check out those massive galvanized iron pipes.  Lots of history at this place.

Tuesday, December 8, 2009

Please take our stream table survey!

We're resubmitting a proposal to NSF to develop stream table curriculum in collaboration with no less than eleven institutions, led by Southern Illinois University-Carbondale. 

Can you help? We're asking for information on existing stream tables, or movable bed river models (MBMs), my preferred term.

We've set up a very short (<3 minutes) survey here. Please complete it if you can.

And forward to your geoscience colleagues!  Here's the full link for cutting and pasting: