Archive for July, 2012


Water-Energy Nexus Goes mainstream

Post from Jeffrey Winters:

Jeffrey Winters

Water plays a little appreciated but crucial role in the cooling systems of most thermal electric generating plants—a plant with cooling towers, for instance, will consume about 400 to 500 gallons per megawatt-hour due to evaporation. If water consumption is restricted, due to drought or some other reduction of flow in the source of water nearest the facility, the power plant may have to reduce production or shut down entirely.

Because of this, the connection between power production and water use has become a topic of great interest at ASME. In 2008, the Center for Research and Technology Development published the ASME Water Management Technology Vision and Roadmap, and a research committee on water management technology produced the ASME Water Management Technology Best Management Practices and Innovations for the Process Industries in 2010. And at last year’s congress, there was a whole technical track dedicated to what’s called the water-energy nexus.

The magazine has covered the topic as well, most notably in Mike Hightower’s feature article, “Energy Meets Water,” in July 2011.

Now the connection has made the Op-Ed pages of the New York Times. On July 24, the Times published an article by Michael E. Webber, an assistant professor of mechanical engineering at the University of Texas in Austin, called, “Will Drought Cause the Next Blackout?”

Webber discusses some of the effects the national drought is already having. In Texas, for instance, some cities have declared a moratorium on the use of municipal water in hydraulic fracturing operations to preserve dwindling reserves for domestic use. Fortunately, Webber writes, there are solutions at hand. Some are obvious.

“The government should also invest in water-related research and development (spending has been pitifully low for decades) to seek better air-cooling systems for power plants, waterless techniques for hydraulic fracturing, and biofuels that do not require freshwater irrigation.”

But others are not as obvious, and will likely strike some stakeholders in coal power as controversial.

“New carbon emissions standards can also help save water. A plan proposed by the Obama administration (requiring new power plants to emit no more than 1,000 pounds of carbon dioxide per megawatt hour generated) would encourage utilities to choose less carbon- and water-intensive fuels. Conventional coal plants, which are very thirsty, exceed the standards proposed by the president. But relatively clean, and water-lean, power plants that use wind, solar panels and natural gas combined cycle, would meet them. Thus, by enforcing CO2 limits, a lot of water use can be avoided.”

What is indisputable is that the water-energy nexus left the engineering world to become part of the national discussion.


journey through India

Post from Harry Hutchinson:


Harry Hutchinson

I was looking at some articles from The Hindu Business Line the other day and came across another road trip story.

Road trips are fun—like the one that General Electric’s Freshpedition, created to publicize a new refrigerator. That’s the subject of the June 13 installment on this blog.

My last road trip took me to the Blue Ridge Mountains where I discovered some great craft ales from the Highland Brewery near Asheville, N.C. I also found some good wines in Virginia.

Business Line was reporting on a trip to publicize the new line of BharatBenz trucks. The trucks are designed specifically for the Indian market and are made in Chennai by a Daimler A.G. subsidiary, Daimler India Commercial Vehicles.

The company called it the “Power Yatra.” I had to look that one up. “Yatra” is Sanskrit for “journey.” And it was lengthy journey, more than 8,000 kilometers between April 18 and July 11 with a convoy of six light and heavy trucks.

Business Line attended the press conference that followed the trip. The Daimler crew claims it talked to about 3,000 truck drivers, as well as mechanics, some of whom, readers were told, operated “under trees.”

Now, I’ve never been to India, so I don’t know what one finds on a road trip. Maybe craft ale and regional wine. But Daimler found something it needed to know.

The new trucks have engine brakes, for instance. The brake pedal doesn’t have to be worked too hard, but Indian truck drivers from long experience are used to jamming on the brakes. The new trucks begin to accelerate when the clutch is release. That, too, will be new to India’s truck drivers. Daimler says it will have to assign at least one master driver at each dealership to show new owners the ropes.

Another point they learned: rooftop luggage racks are not an option; they are required.


Trusting the Voice in the Computer

Post from Jean Thilmany:

Jean Thilmany

I’m just putting this out there. I don’t trust Siri, the voice-recognition program on the iPhone 4S that you “talk to as you would a person” and “it understands what you say” and returns relevant information. (The quotes are from Apple’s web site.)

Problem is, Siri seldom understands what I say. And I don’t think I overmuch mumble. It’s to the point where my six-year-old son has devised a game asking her (okay, we do anthropomorphize Siri—or whatever term you’d use for a disembodied voice) common questions just to hear the hilarious-to-him results. “Who is Dr. Bunsen Honeydew’s Assistant on The Muppet Show?”

“Searching the web for Spongebob?”

She’s frequently tapped as a guest on National Public Radio’s Marketplace Tech Report and has similar things to say.

For example, here’s a transcript from the May 31 show, (which can also be found by clicking here).

Here to discuss recent developments at Apple, our regular expert on Apple, Siri, the personal assistant from the iPhone 4S.

Host John Moe: Hi Siri.

Siri: I didn’t find any meetings.

Moe: I didn’t ask you for any meetings. I was just saying hello.

Siri: Hello.

Moe: Apple’s CEO Tim Cook says TV is an area of intense interest for the company, but in a recent interview, he said there was no imminent launch of an Apple television set, despite a lot of rumors that it’s on the way. Siri, is Apple making a TV?

Siri: I haven’t a clue.

Moe: Oh, that’s how it’s going to be. OK, let’s move on. Next item. Some photos have leaked online of what looks like a case for a new iPhone, but with a much bigger screen. Siri, will the iPhone 5 be bigger?

Siri: There’s no iPhone number for Will Ferrell in your contacts.

Moe: Wait, who’s talking about Will Ferrell.

Siri: Checking on that for you. OK. How about a web search for who’s talking about Will Ferrell?

Moe: No no. Forget it. OK, last thing. Tim Cook also says that he wants to use you, Siri, in more Apple products. Siri, where are you going next?

Siri: Wherever you are. That’s where I am.

Nor do I trust the voice-recognition computerized woman that rides aboard my 2012 Ford Fiesta. She gives me similarly unreliable results. When I asked her to call my husband, Dan, recently she began automatically dialing my grandma, Jean Van Drimmelen. This was long past my grandmother’s bedtime—and I couldn’t figure out how to stop the call!

But researchers at Clemson University in Clemson, S.C., beg to differ with my unscientific findings. They found that computerized aids that include person-like characteristics inspire trust and dependence among adults.

Richard Pak, a psychology associate professor at the university, examined how human decision-making is affected by a human-like aid. He and his team members’ study focused on adults’ trust, dependence, and performance while using a computerized decision-making aid for persons with diabetes.

The study is one of the first to examine how the design of decision-support aids on consumer devices can influence the level of trust that users place in that system and how much they use it, Pak said. The design and look of an aid are important elements for designers because of the potential dangers associated when users trust unreliable decision aids or lack trust for reliable aids simply because of the their appearance, he added.

“Figuring out how trust is affected by the design of computerized aids is important because we want people to trust and use only reliable aids,” Pak said.

Pak’s study was published July 17 in the journal Ergonomics. The journal article was co-authored by Clemson researchers Nicole Fink, Margaux Price, Brock Bass and Lindsay Sturre.

For now, I’m not making health decisions based on Siri or any other computerized aid’s input. Myself, I don’t think the time is ripe for that. Maybe in the future. After all, Siri doesn’t even know the name of my favorite Muppet, Beaker.


Flying into the sun

Post from Harry Hutchinson:


Harry Hutchinson

Switzerland is a pretty cool place. I spent a week there a few years ago touring some of the country’s factories and several of its bars.

I wrote about that—the factories, anyway—in “Traced Back to the Watch,” in the January 2009 issue. The theme of the tour was micromanufacturing, which the Swiss have developed to a high degree in order to support one of their key industries, watchmaking. The micromachining and automation technologies they have refined continue to support the watch business, but also are used to make products ranging from medical devices to parts for miniature motors.

More recently, I’ve been checking in from time to time on something else cool in Switzerland. For the past few years, a project led by Bertrand Piccard, a psychiatrist, and André Borschberg, an engineer, has been developing a solar-powered airplane that—get this—they want to take on a non-stop flight around the world.

Their team, which contains about 90 people—engineers, technicians, mission controllers—has been testing a plane called Solar Impulse. It has made several flights, and so far, it has gotten as far as Morocco.

It isn’t fast, but it’s a gorgeous thing, with its long, flexible wings and extreme streamlining. Piccard was the pilot for the flight back to Europe, which went from Rabat to Madrid. Part of the fun, he wrote on the project’s website (, was that for a while the headwind was greater than the airspeed of his plane, so he was flying backwards.

The whole idea of the attempt puts me in mind of the experimental aircraft built more than 30 years ago by Paul MacCready’s company AeroVironment. One was the Gossamer Albatross, world’s first human-powered aircraft, and the other, the Solar Challenger, was solar-powered. They both won prizes, and places in the Smithsonian Air and Space Museum, by making historic flights. According to AeroVironment (, the human-powered plane crossed the English Channel in a 26-mile flight. The solar-powered plane traveled a total of 163 miles from Corneille-en-Verin Airport near Paris to a Royal Air Force base in England.

As someone who likes to ride a bicycle now and then, I got a bigger kick out of the Albatross. But it’s interesting to see how the Solar Impulse team is trying to extend its range. Rabat to Madrid is about three times farther than the trip from France to England.

What’s more, I’ve read that MacCready’s solar-powered plane carried no energy storage devices. Solar Impulse landed in Madrid at night, so the team proved the aircraft can fly when the sun is down.

Piccard was half of the team that completed the first non-stop balloon flight around the Earth. Will he and Borschberg be able to take a solar-powered plane on the same kind of journey? That would mean making and storing enough energy while the sun shines to carry them through the night.

I couldn’t think about making the trip. I’d go stir-crazy sitting in such a tight space for days on end.

Maybe the plane will have to land before it gets very far. Who knows?

But that’s the nature of an experiment. Nobody knows what works until somebody tries it.


What Price Art?

Post from Jean Thilmany:

Jean Thilmany

I come from a long line of antiquers—or junkers as my grandma calls us—who scour back alleys, thrift shops, and garage sales for items that cost only a few bucks but are of value to us (like a 1950s teenybopper romance novel for me, or a Depression-era glass vase for grandma). But we also seek that one woebegone piece of junk overlooked by everyone else that we know to be worth $400 more than the $14 asking price!

Everybody loves a find. Whole television shows, like Antiques Roadshow, and American Pickers are built around this simple get-rich-quick concept. Problem is that you pretty much have to be a specialist in a particular field to know what something will sell for “at auction”—eBay or Sotheby’s.

I’ve always been curious about why items, particularly paintings, fetch the prices they do at auction. The whole pricing structure seems so capricious. But now, Arzu Aysin Tekindor, an artist and economics PhD candidate at Washington State University in Pullman, Wash., has devised an economic model that gets at that question.

The model reveals why some paintings sell for astronomical prices, like the record auction price of $120 million fetched for Edward Munch’s The Scream earlier this summer. The Munch painting brought so much because it’s The Scream, which is arguably a part of popular culture today. Think of Macaulay Culkin making his memorable face in the Home Alone movie posters.

Tekindor ran her analysis by calculating how each of some 60 characteristics contributed to the overall price. She ranked the auction-house prices of more than 1,100 paintings chosen at random from the lifeworks of 15 great artists, including Pablo Picasso, Gustav Klimt, and Salvador Dali. She also gauged their popularity by counting Google hits on the artists, which corresponded closely with the millions of dollars that their works fetched.

She found that a mere 1 percent increase in an artist’s Google hits increases the average price of his or her work by 28 percent.

The research has implications for both artists and consumers, says Tekindor. Artists, she says, will do well to keep in mind that their style and the objects they portray can have big impact on their career. Consumers should also bear in mind an artist’s style and content, not just his or her name.

That information helps clear up some of the mystery behind auction prices and it’s good to know should I ever get into art collecting. But realistically, I think I’ll probably be sticking to collecting used paperback books.


Manufacturing Looks Strong, or Does It?

 Post from Alan  Brown

Alan Brown

Two recently released surveys show how the economy continues to unsettle manufacturers and business owners.

The first,’s Industry Market Barometer, focused exclusively on product and custom manufacturers. It was taken in January and February, and included more than 1,600 professionals, mostly from small companies with less than 100 employees and less than $10 million in revenue.

Most were optimistic about the future. Nearly half said their business grew in 2011, and 70 percent expected it to grow this year. Top growth markets included aerospace/defense, energy, fabricated metals, medical equipment, and instrumentation, automotive, and construction.

Investment and hiring reflect growth. An impressive 83 percent said they would invest in new production capacity. An additional 71 percent planned to upgrade facilities, and another 66 percent planned to add new product lines or services. Only 28 percent of respondents had trouble borrowing capital for these investments, a source of contention for many small companies during this prolonged recession.

Four out of 10 product and custom manufacturers planned to add employees in 2012, while another five of 10 expected to keep their workforce level. Less than one out of 10 companies foresaw workforce reductions.

Among companies planning to hire 52 percent expected to add line workers; 48 percent, skilled trade workers; 39 percent, engineers; 31 percent sales and marketing personnel; and 27 percent, customer service representatives. Nearly six out of 10 companies said it was hard to find qualified workers.

Despite the upbeat outlook, 61 percent of respondents said they struggle with pricing pressures, and nearly half were concerned about customers cutting back or going out of business. While 39 percent worried worry overseas competition, nearly as many, 36 percent, fretted about domestic competitors.

One way companies respond to competitive threats is by reevaluating their supply chains. Nearly all respondents—85 percent—planned to do this, and more than half will put more effort into that process. This may result in more companies sourcing products in the United States. In fact, 31 percent expect to buy more U.S. products than last year.

ThomasNet, the online version of that old standard, the Thomas Register, trumpets the results as proof that American manufacturers are “laying out an agenda for restoring their industry to its earlier glory.”

Yet the survey was at the start of the year, when the economy was rebounding and U.S. exports were soaring. A more general survey of business executives taken by McKinsey in June paints a more clouded picture.

A lot happened between February and June. Questions about European sovereign debt and the future of the euro have dominated economic news. The economies of China, Brazil, and India showed signs of slowing, as did smaller emerging markets. Uncertainty, slower growth abroad and shaky consumer confidence has caused the U.S. economy to slow.

Only 20 percent of respondents expected the global economy to improve over the next six months. In Europe, 32 percent of executives expect a recession, while 35 percent see a minimal economic contraction. Executives in developing markets and North America are the most optimistic, yet only 38 and 36 percent, respectively, see better conditions in six months.

And manufacturing? Among executives in this sector, 24 percent expected demand to decrease, compared with 13 percent three months ago.


Searching for energy sources

My July column in Mechanical Engineering magazine.

Everyone is searching for a sustainable, renewable, and powerful energy source—including Loki and the alien race Chitauri. Loki is a supervillain in Marvel Studios’ latest hit film, The Avengers. He is sent to Earth by the leader of Chitauri to retrieve a powerful energy source of boundless potential. 

In the film, this untapped source comes in the form of a tesseract. It turns out that we have been surreptitiously cultivating this power source here on Earth, even though we don’t yet fully comprehend its value. The plot revolves around the quest to secure the Holy Grail that is energy independence and control of our own destiny. Sound familiar?

To combat the threats from the outer space rogues, a U.S. espionage agency curiously resembling the CIA activates its “Avengers Initiative” to help fight the enemy and recapture this treasured tesseract. The initiative brings together a group of superheroes who present the only chance of keeping the extraterrestrial villains from destroying the world—to say nothing of Manhattan, where the final battle is waged. But before we get to that, the Avengers—which include Captain America, Iron Man, the Hulk, and Thor—become divided over the approach they should take. As the superheroes argue and lose focus, the goal becomes more elusive.

The superheroes finally figure out that the prize outweighs individual agendas and they come together on a plan. I won’t spoil the ending for those who haven’t yet seen the film. But I wish I could tell you how our own, real life, often angry, debate over energy alternatives will end.

Until we come together with our own plan, one that is comprehensive and sustainable, we remain subjugated to the whims of political and market forces rather than control our own energy future. There are too many justifiable unanswered questions and too many agendas to figure out the odds on how the energy issue will be resolved.

Some believe it will take too long for new technologies to make a dent in the energy mix. They blame technology, infrastructure, and politics. Some believe fossil fuels will continue to play a major role into the future and therefore more attention should be placed on them. Others question the long-term viability of coal, oil, and natural gas, and believe we must move aggressively into alternatives, such as nuclear, wind, solar, and other renewables. Everyone is unsure of consumer behavior, and then there is the uncertainty of current and future regulations in the U.S. and throughout the world.

In this issue we offer two points of view on the U.S. energy regulation debate, as two former ASME Federal Fellows who worked on different sides of the political arena offer their perspectives. Also this month, we present several takes on topics influencing power and energy, plus an interesting discussion on the impact of risk on public acceptance of energy solutions.

It’s no coincidence that we include these articles this month, as we salute ASME’s Nuclear Engineering Division and the Power Division for their decision to collocate ICONE and POWER 2012—two individual events coming together this month under the theme: Energy Mix for a Sustainable and Bright Future. Organizers and those attending the Anaheim event will be actively pursuing sustainable solutions to our energy needs, and even though they won’t have to contend with Loki, the task is no less challenging.


Efficiency by the Numbers

Lee Langston

The following is an article that was originally written as a “web exclusive” on the magazine’s website. Due to popular demand, we are running it again here.

When policy makers sketch out future energy scenarios, they too often overlook the best technology we have.
By Lee S. Langston

One would be hard pressed to come up with a more star-studded line-up than the attendees at the National Academies Summit on America’s Energy Future, which I attended in Washington in March 2008. The two-day summit featured some 26 presentations providing an overview of recent influential energy research studies and initiatives, and like Scrooge’s Christmas visitors, featured Energy Secretaries past (James Schlesinger), present (Samuel Bodman), and future (Steven Chu).

Yet another presenter was New Mexico Senator Jeff Bingaman, chair of the Senate’s Committee on Energy and National Resources. In his remarks, Bingaman illustrated just how long the U.S. has been grappling with energy-related issues with this quote:

“I am inaugurating a program to marshal both government and private research with the goal of producing an unconventionally powered, virtually pollution-free automobile within five years.”

That was President Richard Nixon, addressing Congress in 1970.

The talks centered around renewable energy, the oft-mooted hydrogen economy, and kicking the oil habit, but as with other recent general energy conferences I have attended, there was almost a complete lack of serious discussion on the contribution of gas turbines. Sometimes in such discussions, gas turbines are referred to as a transitional technology, on the way to the employment of some future, emerging energy converter (e.g. the fuel cell, solar energy plants, or wind turbine farms). But they are not presented as a key technology that could well play a central role in the nation’s—and the world’s—energy future.

Which, in my view, is what gas turbines are. No other technology currently available or likely to be deployed in the next decade has the potential to obtain so much power from so little energy. In a future where fuel supplies are likely to be constrained (due to geological, climatological, political, or economic factors) the inherent efficiency of the gas turbine will not be overlooked.

To illustrate the way the gas turbine changes the fundamental assumptions about energy converters, consider the superstar of electricity production, the combined cycle gas turbine power plant. These plants operate at thermal efficiencies approaching 60 percent, which makes them far and away the most efficient large energy converters we have.

Understanding why this is so impressive requires reflecting on the Second Law of Thermodynamics. Lord Kelvin presented the idea this way: “It is impossible to construct an engine that, operating continuously, will produce no effect other than the extraction of heat from a single reservoir and the performance of an equivalent amount of work.” For instance, if a power plant engine—say a Brayton cycle gas turbine—receives heat, Qin, from a reservoir (the combustion of a fossil fuel supply or a nuclear reactor), work W (the turning of a generator to produce electricity) is produced, but there must be part of Qin that is rejected as heat, Qout. The engine’s thermal efficiency, h, is then defined as

or in words, useful output divided by costly input, where engineers strive to makeh as large as possible.

The heat that must be rejected (Qout) as a consequence of the Second Law is contained in the gas turbine exhaust. But while that heat cannot be used by the first machine, it can be used to provide energy input to another engine, provided that the temperature of the rejected heat is high enough for the “bottoming” engine to produce more work, and in turn, reject heat as required by the Second Law. Two engines working together in this way are in what has become known as a “combined cycle.”

In the case of modern Brayton cycle gas turbine, its Qout (typically at 1,000 oF (538 oC) is sufficient to produce steam to run a Rankine cycle steam turbine to generate more electrical power. The combined thermal efficiency (hcc) of the two heat engines (Brayton gas turbine and Rankine steam turbine) can be derived fairly simply from the First Law of Thermodynamics and the definition of h (Equ. (1) to get an expression for the thermal efficiency of the combined cycle (CC) given by

hcc= hGT  + hST  – (hGT )(hST )

where hGT  and hST are the thermal efficiencies of the Brayton cycle gas turbine and the Rankine
cycle steam turbine respectively.

That simple equation gives insight as to why combine cycle gas turbine power plants are superstars. Suppose hGT  is 40 percent, which is a reasonable upper value for current high performance gas turbines. A reasonable value for a Rankine cycle operating at typical CC conditions would be 30 percent. The sum of those two individual efficiencies minus their product becomes:

hcc= 0.40 + 0.30 – (0.40)(0.30) = 58 percent.

The efficiency of the two turbines working in combined cycle is, in fact, greater than either of the two heat engines working separately.


Just how did this leap in power plant efficiency come about? Although the combined cycle power plant concept had been proposed in thermodynamic text books for many years, its widespread realization didn’t occur until the early 1990s, when the cumulative effects of long-term gas turbine research and technology ushered in high temperature gas turbine power plants.

We have come a long way from the very first electrical power plant gas turbine, which was built and tested by Brown Boveri in 1939. The 4 MW plant, installed at Neuchatel, Switzerland, had a thermal efficiency of 18 percent, a firing temperature (turbine inlet temperature) of 998 oF (537 oC) and a relatively low exhaust temperature of about 530 oF (277 oC).

Compare that very first power plant gas turbine with one today, the Mitsubishi Heavy Industries M701G2 heavy frame “G Class” gas turbine. It has an output of 334 MW, an h of 39.5 percent, a firing temperature of 2,732 oF (1,500 oC), and a much higher exhaust temperature of 1,089 oF (587 oC). Such a high outlet temperature is eminently suited for combined cycle steam production.

With the much higher exhaust temperature, the Mitsubishi Heavy Industries combined cycle power plant has an overall on-site thermal efficiency of 59.1 percent, yielding an aggregate output of 500 MW. Currently, three of these units with a combined output of 1,500 MW are replacing six conventional steam powered plants (which ran at 43 percent efficiency) with a total output of 1,050 MW, in one third of the plant area, at Tokyo Electric Power Co.’s Kawasaki Thermal Power Station in Japan.

What is the secret to a three-fold increase in efficiency over 70 years? Hard work. Probably more funding for research and development has been fruitfully devoted to the gas turbine—both in its jet engine aviation form and as a power plant—than for any other prime mover. In the last 50 years, for instance, ASME’s International Gas Turbine Institute has had over 15,000 refereed technical papers presented at its gas turbine conferences. And gas turbine research and development has involved a wide range of basic science and technology.

Advanced materials and heat transfer research, for example, has yielded long-lived superalloy turbine blades and vanes (some of them composed of single crystals; see “Crown Jewels,” February 2006) that are operated for tens of thousands of hours in gas path flows at temperatures greatly exceeding alloy melting points. Experimental work, analysis and computer modeling in fluid mechanics, heat transfer, and solid mechanics have led to continued advances in compressor and turbine component performance and life. Gas turbine combustion is constantly being improved through chemical and fluid mechanics research. And this list could continue almost indefinitely.

The gas turbine is every bit as high tech as a fuel cell or a wind turbine, but its low profile makes it easy to overlook. That’s a shame, because as policy makers grapple with the very real challenges facing the world’s energy system, the need for a clean, efficient energy conversion technology will be glaringly apparent. How fortunate it is that such a technology already exists, in the form of the combined cycle gas turbine, ready to be deployed on a much wider scale.


The Editor

John G. Falcioni is Editor-in-Chief of Mechanical Engineering magazine, the flagship publication of the American Society of Mechanical Engineers.

July 2012

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