Nick Olejniczak/Flickr.com

Solving the spill

March 28th, 2012 by Gene

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Listen up, coffee drinkers. Somebody has figured out why you spill your coffee on the way back to your desk. We’ll share, today on Engineering Works!

If you drink coffee, it’s happened to you. Your fresh cup of coffee has sloshed over the edge and onto the floor as you walk. Often, what’s going on is more than clumsiness, and fluid dynamics researchers have figured out what it is.

Fluid dynamics studies how forces affect the flow, or movement, of fluids. Today, the forces are the movements your cup makes as you walk. The fluid is your coffee. As you walk, you’ll see that both the cup and the coffee move quite a bit. This is where the spill starts.

The researchers analyzed high-speed video of people walking with cups of coffee and found that the cups moved in two different ways: big, regular motions as you walk, and smaller, irregular motions from uneven floors or when you get distracted.

Sometimes the movement of the cup reinforced the flow of the coffee — sort of like when you push your children in playground swings. If you push at just the right time, the swing goes higher. So does the coffee, until it sloshes over the rim of the cup.

The problem could be solved by changing the design of coffee cups so the coffee can’t move so much or so fast.

Our coffee cup works just fine, and we’ll see you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

http://engineeringworks.tamu.edu

Start the discussion: Sometimes research like this seems pretty silly, but this could have implications beyond the coffee cup – anywhere you have liquids that move, in tanks or big pipes, say. Interesting stuff, we say.

For more:

http://www.scientificamerican.com/article.cfm?id=fluid-dynamics-in-a-cup

http://www.engineeringontheedge.com/?s=coffee+fluid+dynamics&search=Search

http://meeting.aps.org/Meeting/DFD11/Event/154769

Trashing the skies

March 21st, 2012 by Gene

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If you look up into the sky, you don’t see much until the moon comes up. There’s a lot there you can’t see. We’ll check it out. Today, on Engineering Works!

Beginning with the Sputnik satellite in 1957, we’ve been sending stuff into space for more than half a century. Most of it is still there. The latest count shows about two-thousand active satellites and more than 13,000 other objects four inches or more across. There’s so much smaller stuff that keeping track of it is impossible.

This means that the chance of orbital fender-benders is getting bigger all the time. In 2009, a Russian Cosmos satellite and an Iridium communications satellite did collide. Neither survived. The space shuttles used to return to earth regularly with dings from orbiting junk as small as a chip of paint.

There’s more. This orbiting junk doesn’t stay in orbit forever. Eventually, it all comes back to earth. And some of it is big enough to hurt if you get hit with it.

Scientists and engineers are trying to figure out what to do. Ideas range from launching special satellites to gather or destroy orbiting junk to designing future spacecraft so they’ll burn up when they finally hit earth’s atmosphere. That doesn’t always happen now. In fact, titanium, the light, strong metal many spacecraft parts are made of, often falls to earth without much damage.

We haven’t been hit yet, but we’re still done for today. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

http://engineeringworks.tamu.edu

Start the discussion: This seems almost like a problem without a solution. This orbiting junk is up there where we can’t get at it easily, and most of it is so small we can’t see it. Anybody got any ideas?

For more:

http://latimes.com/news/local/la-me-space-junk-20120122,0,819657.story

http://blogs.scientificamerican.com/guest-blog/2012/01/14/where-did-all-that-space-debris-come-from/

http://science.nationalgeographic.com/science/solar-system/orbital/#

http://urthecast.com/corporate/uncategorized/steering-clear-the-science-of-space-junk

NASA

Stepping off the grid

March 14th, 2012 by Gene

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Most of us take electricity for granted. We’ll look into an unusual way to keep the lights on. Today, on Engineering Works!

It’s hard to think of getting through the day without electricity. It gets us up in the morning, helps us find out what’s happening, cooks our meals, keeps us entertained.

In the United States, we use almost four-trillion (with a T) kilowatt-hours of electricity a year. A kilowatt-hour is a thousand watts of electricity for an hour. It’s enough to burn a forty-watt light bulb for 24 hours or power your computer for two-and-a-half hours. We use more electricity than any other country on Earth.

We depend on our nationwide electric distribution network to keep the lights on. That’s fine, but when it goes down, a lot of us end up in the dark. Like what happens when a big snowstorm or hurricane hits.

Power engineers and policymakers have a way to deal with the situation. Instead of the big national electric grid, why not break it up into a whole lot of little networks, called microgrids? Individual cities or counties would have their own generators and separate distribution grids.

In normal times, they’d sell electricity to the national system, but if part of the big grid nearby goes down, they’d automatically disconnect from the damaged part and the lights would stay on. The idea needs some work, but it sounds promising.

Our grid is up, but we’re shutting still down. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

http://engineeringworks.tamu.edu

Start the discussion: We understand about the economies of scale – the advantage to doing some things big, but stepping back to a system of small grids seems to make sense. Yes? No? Tell us what you think.

For more:

http://ctmirror.org/story/15148/microgrids-offer-potential-greater-energy-reliability

http://certs.lbl.gov/certs-der-micro.html

http://www.nationmaster.com/graph/ene_ele_con-energy-electricity-consumption

http://www.eia.gov/

Zorin Denu/Flickr.com

Timing the future

March 7th, 2012 by Gene

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Time is fascinating stuff: just ask Albert Einstein. Let’s take a look. Today, on Engineering Works!

To understand time, we need a way to measure how much time has passed. Clocks of one kind or another have been around for at least 6,000 years. Early clocks used dripping water or the movement of a shadow across a sundial to tell time.

The first really accurate clock was built in 1759 by an English carpenter and clockmaker. It was incredibly accurate for its time, gaining or losing no more than a second a month. Sailors needed this kind of accuracy to figure out easily where they were, east and west, their longitude. Before this, top-quality clocks and watches might gain or lose a minute a day.

Fast forward to today. We use time – and clocks – to do things sailors in the 1700s never dreamed of. For instance, modern GPS locating devices depend on clocks that gain or lose less than 10-millionths of a second. This sounds like really small, but engineers and scientists are hard at work on even more accurate clocks.

For instance, an experimental clock based on the vibration of a single mercury atom gains or loses no more than one second in a quintillion seconds. We didn’t make that up. That’s a second in almost 32 million years. And other clocks promise to be at least as accurate.

Our clock is nowhere near that accurate, but it still says we’re done. See you next time.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

http://engineeringworks.tamu.edu

Start the discussion: It’s easy to wonder how much all this accuracy is worth. Apparently, it’s worth quite a bit. We all know about the need for accurate time in GPS devices; what other technology needs ultra-accurate timekeeping?

For more:

Dava Sobel, Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of his time. Penguin Books, 1995

http://en.wikipedia.org/wiki/Clock

http://www.nature.com/scientificamerican/journal/v16/n1/full/scientificamerican0206-56sp.html

http://www.sciencenews.org/view/feature/id/334983/title/The_Ultimate_Clock