Engineering

Whether after tsunamis in Japan and Indonesia, hurricanes like Katrina and Sandy, typhoons in the Philippines, or even during search efforts after last month’s lost Malaysian Airlines flight, waves have been the focus of many urgent conversations in the past decade. Anyone who has a home on or near a coastline is talking more these days about the simple calculus of storm surges, beach erosion, and sea level rise than ever before.

Into this discussion last fall came Waves, a new book by Fredric Raichlen SM ’55, ScD ’62, a civil engineering professor emeritus at the California Institute of Technology. aas

Raichlen’s deceptively simple book, part of MIT Press’s Essential Knowledge Series, teaches its readers all the basics about waves, then takes direct aim at this century’s most pressing concerns about them. Listen to Raichlen’s discussion of the book in this month’s Alumni Books Podcast.

Raichlen, who studied waves at MIT’s hydrodynamics lab in the 1950s (now the Parsons Lab), says the book was his way to dial back the hysteria waves cause and ground readers in their fundamentals. In Waves, one learns that:

  • A tsunami, even far out to sea, is considered a shallow-water wave.
  • The sun has as much to do with tides as the moon does.
  • A storm in Alaska can cause wave damage to shorelines in Los Angeles, over 3,000 miles away.

“I wanted to lay down some of the basics of ocean waves in a simple fashion, and in the latter part of the book talk about areas I had become involved in both in research and in engineering consulting,” says Raichlen, who taught and conducted research at Caltech for nearly 50 years before retiring in 2001.

Readers will notice that the book sticks to its premise of essential knowledge and stops shorts of editorializing on climate change. “I really wanted to avoid that,” Raichlen says in the podcast. “Climate change and sea level rise are important to our coastal regions…[but] things are really not that definite in terms of quantitative estimates of sea level rise and there’s a wide range of ideas of the magnitude and rate of sea level rise. So I wanted to talk about things more definite.”

raichlen sound

Listen to the complete podcast here. Listen to past books podcasts on optics, health care, and architecture by visiting MITAA on Soundcloud.

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Guest Post by Peter Dunn from the Ask an Engineer series, published by MIT’s School of Engineering

In an era when everything else is accelerating, airplanes are actually flying at slower speeds than they used to…

A 1950s advertisement for the Boeing 707; Credit: 1950s unlimited

“Your link to faraway continents in hours less time: the new, fabulously swift Boeing 707.”
Credit: 1950s unlimited

Specified cruising speeds for commercial airliners today range between about 480 and 510 knots, compared to 525 knots for the Boeing 707, a mainstay of 1960s jet travel. Why? “The main issue is fuel economy,” says Aeronautics and Astronautics professor Mark Drela. “Going faster eats more fuel per passenger-mile. This is especially true with the newer ‘high-bypass’ jet engines with their large-diameter front fans.”

Observant fliers can easily spot these engines, with air intakes nearly 10 feet across, especially on newer long-range two-engine jetliners. Older engines had intakes that were less than half as wide and moved less air at higher speeds; high-bypass engines achieve the same thrust with more air at lower speed by routing most of the air (up to 93 percent in the newest designs) around the engine’s turbine instead of through it. “Their efficiency peaks are at lower speeds, which causes airplane builders to favor a somewhat slower aircraft,” says Drela. “A slower airplane can also have less wing sweep, which makes it smaller, lighter and hence less expensive.” The 707’s wing sweep was 35 degrees, while the current 777’s is 31.6 degrees.

There was, of course, one big exception: the Concorde flew primarily trans-Atlantic passenger routes at just over twice the speed of sound from 1976 until 2003. Product of a treaty between the British and French governments, the Concorde served a small high-end market and was severely constrained in where it could fly. An aircraft surpassing the speed of sound generates a shock wave that produces a loud booming sound as it passes overhead; fine, perhaps, over the Atlantic Ocean, but many countries banned supersonic flights over their land. The sonic-boom problem “was pretty much a show-stopper for supersonic transports,” says Drela.

Some hope for future supersonic travel remains, at least for those able to afford private aircraft. Several companies are currently developing supersonic business jets. Their smaller size and creative new “boom-shaping” designs could reduce or eliminate the noise, and Drela notes that supersonic flight’s higher fuel burn per passenger-mile will be less of an issue for private operators than airlines. “But whether they are politically feasible is another question,” he notes.

For now, it seems, travelers will have to appreciate the virtues of high-bypass engines, and perhaps bring along a good book.

Visit the MIT School of Engineering’s Ask an Engineer site for answers to more of your questions.

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Once again, MIT has been ranked the best graduate engineering school by U.S. News & World Report, the position MIT has held since 1990 in the magazine’s annual ratings of graduate schools. Who’s next in line? Stanford, UC Berkeley, and Caltech.

How the world sees MIT.

MIT from above.

In the School of Engineering, top-ranked graduate engineering programs include aerospace engineering; chemical engineering; materials engineering; computer engineering; electrical engineering (tied); mechanical engineering (tied); and nuclear engineering (tied).

USNews and World Report does not rank all disciplines annually. In the first sciences evaluations in several years, the School of Science took the top spot in biological sciences (tied); chemistry (tied) plus an additional top ranking in the specialty of inorganic chemistry; computer science (tied); mathematics (tied) plus top ranking in discrete mathematics and combinations; and physics.

The MIT Sloan School of Management’s graduate programs in information systems, production/operations, and supply chain/logistics were again ranked first this year; Sloan was ranked the #5 business school.

Read the MIT News article to see which other MIT disciplines scored in the top five nationally and the contenders in the ties.

 

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Guest Blogger: Camilla Brinkman, Edgerton Center

MIT alumni of the 2004 Remote Operated Vehicle (ROV) team play a role in a new documentary film, Underwater Dreams, the story of four Mexican-American teenagers from an impoverished area of Arizona who challenged and beat the MIT team in a national contest, a feat that drew national media attention.

“Passionate engineering knows no boundaries, and to celebrate these students’ impressive feat was the right thing to do,” says Ed Moriarty '76, during the filming. He first invited the team to MIT in 2004.

“Passionate engineering knows no boundaries, and to celebrate these students’ impressive feat was the right thing to do,” says Ed Moriarty ’76. From left, Oscar Vazquez, Lauren Cooney ’06, SM ’09, and Moriarty during filming. Photo: Camilla Brinkman.

Recently the Edgerton Center invited the MIT and Arizona team members to campus to film commentary on the impact of the Marine Advanced Technology Education ROV Competition on both teams. The filming captured comments by Kurt Stiehl ’07, Lauren Cooney ’06, Jordan Stanway ’06, and Thaddeus Stefanov-Wagner ’06 as well as the Carl Hayden Community High School team and coach.

“I was thrilled because I knew how much the invitation [to MIT] would mean to the Carl Hayden students. In 2004, they had not really had the opportunity to interact with the MIT team. But more importantly, as Oscar Vazquez later said, the invitation was such a sign of respect for what these boys and this team from Phoenix had accomplished,” said Mary Mazzio of 50 Eggs Films, who wrote and directed the film.

The Carl Hayden team had been invited to MIT to celebrate the tournament but they could not travel by plane because they were undocumented.

During the filming, each team commiserated about their mishaps at the 2004 competition.

The Carl Hayden team’s soldered robot components melted in the hot Arizona sun en route to the competition. MIT’s robot suffered catastrophic damage in transit and had to be rebuilt. Then, the day before the competition, the Carl Hayden team discovered that the mechanical housing of their robot was leaking. One team member came up with an ingenious solution—tampons as a plug.

“What the Carl Hayden team did was totally impressive,” said Stiehl, now a product designer at Apple, who credits landing his job to the hands-on experience he gained on the ROV team. “The practicalities of shipping products versus building a robot are surprisingly similar and I use everything from basic system architecture development to project scheduling and team building.”

“It’s still affecting my life, even 10 years after,” said Oscar Vazquez, a Carl Hayden alumnus. “It gave me a career in engineering; it helped me pay for college; it brought me to MIT today; it sent me on the right path.”

And the story is still unfolding. Along with Underwater Dreams, another film about the Carl Hayden team, starring George Lopez and Marisa Tomei, is set to be released in the fall.

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Guest Blogger: Bill Doncaster, for MIT Sloan

The 2014 MIT Sloan Women in Management (SWIM) Conference added a new challenge this year, a chance for MIT women entrepreneurs to pitch their startups for a $1,000 prize. Held February 8 at the MIT Media Lab, this is the first time such a competition was held for women entrepreneurs at MIT.

Systems president Natalya Brikner presents her satellite propulsion technology.

Systems president Natalya Brikner presents her satellite propulsion technology.

Ten startups, selected from 30 applications MIT-wide, presented new ideas ranging from app-based parenting resources for educational activities to a new device to monitor and prevent leg injuries for prize show horses. In the end, the high-caliber presentations led to a quandary for the panel of three judges—who chose two winners rather than one for the $1,000 prize.

One winner was Accion Systems, presented by CEO and president Natalya Brikner. Accion, which is developing propulsion systems for small satellites, is queued up for its first space test in April. Most of the 300 or so satellites launched each year remain only in orbit for days because there is no propulsion system to keep smaller satellites in orbit. According to Brikner, a PhD student in the Department of Aeronautics and Astronautics, Accion’s cost-effective systems would increase the life and operability of small satellites.

“The engines that are flying on satellites today were designed before the first handheld calculator was invented,” Brikner said. “We want to change that. Our systems are lighter, smaller, and more efficient than existing systems and our product line is infinite—customers can put thrusters anywhere they want on a satellite.”

Caroline Mauldin, a first year student in MIT Sloan’s dual degree program with Harvard’s John F. Kennedy School of Government, stayed closer to the earth with her company, Love Grain, the second winner. Love Grain serves the growing gluten-free food market through products made with teff, a gluten-free grain from Ethiopia. The company is already selling its first product, a pancake and waffle mix, and is developing an energy bar.

“Here in the United States, there are 42 million gluten-free consumers who lack nutritious and delicious options, and I know that because I’m one of them,” said Mauldin. “We’re expected to spend $6 billion on gluten free products by 2015. Teff is a tiny part of the market right now. We are creating a sustainable, compassionate business model that connects Ethiopian farmers to the United States.”

Learn more about the pitch contest and the conference.

 

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Guest Post by Sarah Jensen from the Ask an Engineer series, published by MIT’s School of Engineering

Engineering “enhancements” are already generating debate in the world of sports. There are only going to be more…

Olympians compete in the London 2012 Paralympic Games; Photo: Swamibu

Olympians compete in the London 2012 Paralympic Games; Photo: Swamibu

The history of professional sports is filled with innovations that have improved safety and allowed athletes to push their limits further and further. No one argues the value of improved helmets and shin guards and facemasks or a players’ right to wear them. But the line is beginning to blur between which enhancements are ethical and which should lead to being benched for the duration. “Medical technology is good enough now that we can enhance athletes’ bodies in ways that could give them an unfair advantage over the competition,” says Anette “Peko” Hosoi, associate professor of mechanical engineering at MIT.

“People with artificial limbs can now run as fast as able-bodied athletes,” says Hosoi. “It will come down to policy and regulation as to what is allowed, and what isn’t, in professional sports.”

Making that determination won’t be easy. Currently, the rules of the International Association of Athletics Federations includes a clause banning the use of “any technical device that incorporates springs, wheels, or any other element that provides the user with an advantage over another athlete not using such a device.” That may seem a cut-and-dried ruling, but the wording raises questions of ethics and discrimination. “All artificial limbs contain springs of some sort,” says Hosoi. “How can having no legs possibly be an advantage for a sprinter?”

And it’s not inconceivable that a version of the so-called Tommy John surgery – or ulnar collateral ligament reconstruction – could be one day be developed. Currently allowed for injured ballplayers, the procedure tightens the ligaments in their arm so they can get back into major league pitching form. “The surgery doesn’t insert anything artificial in the arm,” explains Hosoi, “and it can’t increase the pitching speed of an uninjured player.”

But future advances in biotechnology might make that possible, and it’s important for regulators to imagine such scenarios ahead of time — a simple elective tightening of the ligaments, and Junior emerges from the OR hurling them across the plate like Nolan Ryan, a multimillion dollar contract a certain part of his future. A blanket rule forbidding athletes to have the surgery seems like the obvious answer – but it isn’t. “If we decided such surgery was illegal,” says Hosoi, “we’d be telling injured athletes that their career was over.”

The debate is essentially one of ethics, she says, and must involve not only those who regulate sports, but also athletes, ethicists, and engineers. “Mechanical engineers have particular insight into emerging technologies and an understanding of the mechanics of what constitutes unfair advantage,” she says.

And MIT students, with their dual focus on technology and the humanities, are equipped to weigh in on the ethical and philosophical parts of the issue as well. “MIT’s Department of Athletics, Physical Education, and Recreation is interested in working with the governing bodies who make rules for the NCAA competitions,” says Hosoi. “I hope to increase conversations with them; it’s an area where engineers must contribute to the discussion.”

Thanks to Jordan Hester for this question. Visit the MIT School of Engineering’s Ask an Engineer site for answers to more of your questions.

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Guest blogger: Genevieve Wanucha SM ′09

As the New Year begins, Oceans at MIT is gearing up for a whole new batch of stories that explore the ocean-related research and engineering at MIT. It’s the perfect time to take a look back at Oceans at MIT’s past twelve months. The stories are a varied bunch, ranging from new insights into the surprisingly warm climate of the “Cretaceous Hothouse” 50 million years ago to a review of the “Ocean Stories” exhibit produced by Synergy, a newly formed MIT/WHOI experimental art/science organization; and from a highlight of new faculty positions in top climate-ocean science programs earned by recent PAOC members to an update on the Fukushima Disaster clean-up. Here are three highlights:

oceans_Shark-01-10-13Lights, Camera, Action: Revealing the Ocean’s Invisible Beauty A feature on MIT theoretical physicist Allan Adams’ collaboration with underwater photographer Keith Ellenbogen to make the subtle, rapid movements of sea creatures visible to the human eye. They recently used a Phantom V12 high-speed camera and lighting to film New England Aquarium (NEAq) finned denizens, including sharks and lionfish, at 1,200 frames per second in high-def. The videos, when played back in extreme slow motion, expose an awe-inspiring world.

oceans_Sailing-01-10-13Inside the Fastest Boats in America’s Cup History with MIT MechE Oceans at MIT invited professors Doug Hart, Paul Sclavounos PhD ’81, and Jerome Milgram ’61, SM ’62, PhD ’65 to answer a few questions about the fastest yachts in America’s Cup history. Knowing what they know will put the 2013 race between the US and New Zealand in San Francisco into a whole new light.

oceans_waste-01-10-13Before the Wreckage Comes Ashore Oceanographers around the world, with MIT’s mechanical engineer Thomas Peacock at the helm, have found the invisible organizing structures that govern how pollutants move along the ocean’s chaotically swirling surface. Their new application of dynamical systems theory paves the way towards next generation disaster response.

Read the more top stories online from 2013 and visit the Oceans at MIT on Facebook for regular updates.

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Guest Post from the Ask an Engineer series, published by MIT’s School of Engineering

Maybe—if it’s the right type of remote and you have plenty of time and technical know-how (but don’t get your hopes up)…

Photo: Caitlin Regan

Photo: Caitlin Regan

So you’ve lost your car keys again. You’re sure they’re in your house, but you’ve already checked between your couch cushions and on top of the fridge, and you can’t find them anywhere. You have a keyless remote that seems to communicate with your car, and you wonder if maybe there’s a way to get it to communicate with you and tell you where it is. “In theory, it is possible,” says Phillip Nadeau, a Ph.D. candidate in electrical engineering and computer science, “but it depends on the type of remote-entry system we’re talking about. And even then, it could be tough depending on the manufacturer and technology used.”

There are two main types of keyless remotes—Remote Keyless Entry (RKE), and Passive Keyless Entry (PKE)—that work in different ways. RKE devices send a radio signal to your car only when you press a button on the remote. “These devices are generally only equipped with a transmitter,” explains Nadeau. Unfortunately, this means there’s no way to call the remote. It’s as unable to hear you as a skeleton key.

If you have a PKE remote, your odds are better. PKE devices don’t require you to push buttons to lock or unlock your car. “The car sends a signal that simultaneously powers the remote and asks for a valid authentication code to unlock the car,” explains Nadeau. This is essentially the same technology RFID card readers use to give you access to a building without you having to pull your ID card out of your pocket. Unlike a RKE device, a PKE remote has both a transmitter and a receiver, which would allow it to hear you call it with specialized radio equipment—you’re just pretending to be your car! In theory, you could custom-build a device that functions as a radio transmitter and receiver, recording the signal from your car, re-transmitting it, and listening for a response from your keys. This is not an easy or inexpensive solution, but if you have the technical know-how to construct such a device, it should work…

As long as you have a lot of time on your hands, says Nadeau. “The interrogator must be within a few feet the remote to elicit a response.” This proximity restriction is useful most of the time—if PKE remotes had a long range, people could steal the car right out of your driveway while the keys sit safely inside your house! But, it also means that you’re going to have to cover every square inch of your house with your equipment to find your keys. So, you might as well save the time and expense of building some complicated radio equipment and keep looking for your keys the old-fashioned way: going back and pawing through that junk drawer one more time.

Authored by Aaron W. Johnson, a PhD candidate in aeronautics and astronautics. Thanks to Suzan Atkinson-Haverty from Fitchburg, Massachusetts, for this question.Visit the MIT School of Engineering’s Ask an Engineer site for answers to more of your questions, and ask your own. 

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Imagine a tiny device stuck to a car’s front bumper that could scan for cars ahead of you on foggy roads and warn of their approach.

First-year student Saumil Bandyopadhyay. Photo: Alessandra Petlin/Smithsonian.

First-year student Saumil Bandyopadhyay. Photo: Alessandra Petlin/Smithsonian.

You could use that same detector, the size of a postage stamp, to scan for radioactivity in shipping containers, to detect cancer in bones, or to gauge melting on polar ice caps.

MIT first-year student Saumil Bandyopadhyay is thinking through these solutions, given the success of a new nanoscale infrared detector that he co-invented with his father, a professor at Virginia Commonwealth University.

The 18-year old has already impressed Nobel laureates and government and military researchers with his invention. Last month, the Smithsonian honored Bandyopadhyay with its American Ingenuity Award, given for groundbreaking work in the sciences, technology, and humanities.

Named this year’s youth honoree, Bandyopadhyay received his award at the National Portrait Gallery on November 19 alongside Stanford professor Caroline Winterer, acclaimed author Dave Eggers, singer-songwriter St. Vincent, and five others.

Bandyopadhyay’s infrared device capitalizes on nanotechnology to minimize the enormous heat given off by traditional infrared detectors. Requiring no liquid nitrogen to cool it down, the device may prove widely useful, perhaps even aiding the search for new planets or helping to detect land mines.

In his father’s lab at VCU, Bandyopadhyay was able to improve his invention while gaining great experience with chemistry and physics. Bringing the new device to science fairs, he attracted the attention of Nobel laureate astrophysicist John Mather, who alerted Smithsonian to what a great idea it was. “He’s a brilliant kid,” said Mather.

Arriving at MIT this fall, Bandyopadhyay felt right at home and has been enjoying his first experiences studying EECS. The environment on campus, of course, is rife with nanotechnology, with professors and labs discovering uses of it for cancer research, military defense, and chemical spills.

Despite being new to him, the MIT campus provided Bandyopadhyay with some familiarity. The fact that there’s no entryway into MIT dorms labeled “I” gave him a pleasant sort of welcome, as he explained to Smithsonian Magazine this month.

“In math, the convention is that the square root of negative one is I,” he said. “So I is imaginary.”

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Guest Post from the Ask an Engineer series, published by MIT’s School of Engineering

Photo: Theen Moy

Photo: Theen Moy

“If you want to capture energy and use it to power something, it’s true that you can get energy out of a speed bump,” says Amos Winter, an assistant professor in MIT’s Department of Mechanical Engineering and director of its Global Engineering and Research (GEAR) Lab. “You need to think about how you transfer that energy, and how much energy you can actually capture.”

A speed bump pushes the car’s wheels upwards, and when it bounces back to the ground, kinetic energy is converted to potential energy absorbed in its shock absorbers. Capturing some of that energy sounds plausible at first blush. Using piezoelectric sensors, you can generate power by converting some of that force into an electrical charge. “You can produce high voltage, but pretty low current,” says Winter. “The energy of the spark of a piezoelectric barbecue lighter, for example, is less than the energy you put into pulling the trigger.”

The core principle involves work: the application of force over a distance. A car’s force multiplied by the distance it depresses the piezos equals the amount of useful work that can be done – and a car tire rolling over a piezo will depress it only a few microns. Winter suggests a more efficient way of capturing that energy. “Instead of making a speed bump, make a speed divot,” he says. “A flat surface that can be depressed easily will sink down when you drive over it and you can use the weight of the car to spin some sort of generator.” Another scenario is a compressible speed bump made of flexible plastic or rubber filled with water. When a car drives over it, water is squeezed out and can be pumped into a water tower high in the air. “You could run that water through a turbine and produce electricity with it,” says Winter.

Such models, of course, require full-size cars, full-size roadways, and full-size water towers. Scaling down the project to exhibit in the school auditorium is another story. The size of the display may be smaller, but the challenge is much larger. “You could construct a small speed bump and push down on it with a section of a car tire to light up an LED,” suggests Winter. “But a model using Hot Wheels cars? Forget it. They’d never deflect the speed bump enough to produce any energy.”

In the end, the most important thing to keep in mind is that creating energy isn’t just about applying force; it all goes back to the principle of work. “You need force multiplied by a distance,” says Winter. “That’s what shock absorbers do, and a more interesting design could be built around that.” He suggests checking out Levant Power, a company founded by Shakeel Avadhany ’09 and Zack Anderson ’09 to develop and commercialize shock absorber energy recovery.

Authored by Sarah Jensen. Thanks to Jonathan from Atlanta, Georgia, for this question. Visit the MIT School of Engineering’s Ask an Engineer site for answers to more of your questions, and ask your own. 

 

 

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