PURDUE MECHANICAL ENGINEERING

SPRING/SUMMER 2006

d e c i b e l sd e c i b e l squiet ing the urban soundscapequiet ing the urban soundscape

up front

Vin

cent

Wal

ter

From Dan’s DeskWe face unprecedented challenges and opportunities as a discipline, a nation, and a planet—energy, environment, security, and healthcare are among those that top the list. Increasingly we hear how these grand challenges will be solved through multidisciplinary efforts, with implications that collaboration is something new. While it may be new for many, collaborative and interdisciplinary research has been going on in Mechanical Engineering for decades, notably in the Ray W. Herrick Laboratories. Some of the Herrick Laboratories collaborative efforts were featured in the first issue of ME Impact on energy, and more will be covered in this issue focusing on the environment.

Herrick Laboratories was founded in 1958 with a grant from the Herrick Foundation. Bill Fontaine, the founder of the Laboratories, and Ray W. Herrick had a shared vision for multidisciplinary research of benefit to industry. Originally based on a collaboration be-tween mechanical engineers and animal scientists, research at the Labs has expanded to involve psy-chological and hearing sciences, health, and chemi-cal and biological sciences. These interdisciplinary research teams are key to finding innovative solutions to the noise, vibration, safety, energy, sustainabil-ity, and environmental problems that impact our daily lives. The translation of fundamental interdisciplinary research into technological advances of benefit to industry is similarly one of the motivating factors for Purdue’s Discovery Park, Herrick’s next-door neighbor. At Discovery Park, multidisciplinary teams in nano-technology, biosciences, and other emerging fields are located next to, and interact with, entrepreneurial, e-enterprise, and discovery learning activities.

We are now in the midst of a campaign to raise the funds to elevate the Herrick Laboratories to the next level— preeminence. Herrick Laboratories paved the road to collaborative re-search, and now it is time to extend the road. With your help, we will build it!

E. Dan HirlemanWilliam E. and Florence E. Perry HeadSchool of Mechanical Engineering

Your Response to Our Last IssueThe article in ME Impact (Fall 2005)

about the overhauling of hydraulics was of great interest and fascination for me. When I graduated, hydraulics was only a dictionary word in mechanical engineer-ing education. Fluid mechanics was cen-tered on pneumatics. It’s good to see fluid power elevated to a level and discipline equal to machine design, thermodynam-ics, etc.

I started working in aircraft flight con-trols during a dynamic period in the mid-1950s. Systems were then shifting to fully powered servomechanisms. The invention of the electrohydraulic servo valve by Bill Moog enabled the integration of electron-ics and hydraulics in the development of high-performance control and stability augmentation systems. System analysis

was mostly the province of electrical engineers who had advanced con-trol system theories. MEs could only bring up the rear and were stuck with a trial-and-error approach to the prob-lems. Over the years I had an oppor-tunity to work at companies like North

American, Lockheed, Boeing, Vickers, and Moog that gave me a better appre-

ciation for the potential of fluid power… Dick Hurley (BSME ’50) Greencastle, IN

From the EditorThis issue of ME Impact takes the envi-ronment as its theme. From noise-con-trol research in the Herrick Labs (pages 4-7) to Purdue alumnus and professor Cecil Warner’s contribution to the schol-arly study of air pollution (page 11) to Purdue alumnus Ralph Bailey’s take on clean coal (page 3), Purdue mechanical engineers are in the thick of solving some of our most pressing problems. What are your thoughts about their work? Write to us (see address on facing page) and let us know!Lisa Hunt Tally

4

3

contents

10

UP FRONT

From Dan’s Desk • Your Response to Our Last Issue • From the Editor

AROUND ME

Smooth Operators • Chiu, Raman Win College of Engineering Faculty Awards • Faculty Kudos • Welcome to Marisol Koslowski

IN MY VIEW

Alumnus Ralph E. Bailey on Clean Coal

COVER

Damaging Decibels: Herrick Labs on Environmental Noise

RETROSPECTIVE

Andrey Abraham Potter: The Man for All Reasons

UP CLOSE: STUDENTS

Rubber Meets Road: Will Thornton

UP CLOSE: FACULTY

Building a Better Back (Cervical to Lumbar): Ben Hillberry and Eric Nauman

UP CLOSE: ALUMNI

Clean Air: Cecil F. Warner Led the Way

ALUMNI NEWS

Roman J. Krygier Jr.: Built for the Road Ahead • Purdue and Beyond • Father, Son, and Alma Mater

CAMPAIGN IMPACT

One Year and Counting

IMPACT INTERACT

Plumber Puzzle • Jeffrey Henkle Solves “Weightlifter Puzzler” • Coming Up • It’s Your Turn

ME Impact is published for alumni and friends of the School of Mechanical Engineering at Purdue University.

We welcome your comments, opinions, and questions. Please send correspon-dence to the address at right, or e-mail us at peimpact@purdue.edu. In doing so, you grant us permission to publish your letter in part or in whole in an upcoming issue. We reserve the right to edit letters for length or clarity. If you would like to be removed from the ME Impact mailing list, contact Cynthia Dalton at (765) 494-7320 or cdalton@purdue.edu. Produced by the Engineering Communications Office

Equal Access/ Equal Opportunity University.

COLLEGE OF ENGINEERING

E. Dan Hirleman, PhD, Head James D. Jones, PhD, Associate Head Anil K. Bajaj, PhD, Associate Head Keith H. Hawks, PhD, Assistant Head John Sanderson, Director of Development Alicia Pilon, Director of Development Cynthia Dalton, Development Secretary Rwitti Roy, Director of Marketing and Communications, College of Engineering Lisa Hunt Tally, Editor Emil Venere, Contributing Writer Arline Meehan, Martin Sickafoose, Graphic Designers

2

3

4

8

9

10

11

12

14

15

School of Mechanical Engineering 585 Purdue Mall

Purdue University

West Lafayette, IN 47907-2088

(765) 494-7320

www.purdue.edu/ME/

Purdue Mechanical Engineering Impact

around me

Smooth OperatorsA professor’s research could lead to lower-cost,

portable surgical robots.

A mechanical engineer at Purdue is teaming up with medical doctors in research aimed at developing less expensive, portable, and versatile surgical robots that could become more common in operating rooms.

The researchers are also trying to incorporate tactile sensors into the robots to enable surgeons to feel tissue and better diagnose medical conditions.

“Robots don’t perform the surgeries, but they are tools that give the surgeon more dexterity,” says William Peine, an assistant professor of mechanical engineering. “They let you get into confined spaces. You can eliminate hand tremor, and you

can be very precise and delicate. It’s as if the tips of the instruments become your fingertips.”

Current robots are complex and often re-quire a large operating room and extra setup time. The re-searchers are trying to devel-op a new breed of surgical robot that is smaller and easier to use and can be

set up in less time. This would give surgeons the option of deciding to use a robot on the fly if necessary, Peine says.

A key innovation that is ideal for robotic surgery is a technique in which doctors insert thin probes called laparoscopic instruments into the body through small openings, eliminating the need to make large incisions that leave scars and require a lengthy recovery time, Peine says.

Without robots, surgeons manipulate the laparoscopic probes with a handle that remains outside the body. Using such handheld tools presents challenges to sur-geons because it is difficult to manipulate the devices. For example, moving the handle in one direction causes the probe to move in the opposite direction inside the body.

“They call this the fulcrum effect,” Peine says. “If I move the handle up, the tip moves down inside the body. If I move it down, it moves up—left and right are re-versed. But a robot can understand all the mechanics and compensate for them.”

Peine, whose research involves creating both software and hardware for surgi-cal robots, helped form a company called Pressure Profile Systems, located in California, which develops and markets tactile medical devices. He is also affiliated with Purdue’s Regenstrief Center for Healthcare Engineering at Discovery Park, the university’s hub for interdisciplinary research.

—Emil Venere

Chiu, Raman Win College of Engineering Faculty AwardsPurdue Engineering recognized two mechanical engineering faculty members at its 2006 Awards of Excellence this past March. George Chiu (above left), a participant in the Purdue–Hewlett Packard Digital Printing Services Program, received the Team Award with five Purdue colleagues. The program has led to significant innovations in digital imaging and printing systems. Arvind Raman (above right) received the Young Researcher Award for his accom-plishments in the areas of vibra-tions and nonlinear dynamics.

Faculty Kudos Inducted: Jim Braun, as a fellow of the American Society of Heating, Refrigeration, and Air-Conditioning Engineers. Norm Laurendeau, the Ralph and Bettye Bailey Professor of Combustion, as a fellow of the Optical Society of America. Patrick Lawless, as an associate fellow of the American Institute of Aeronautics and Astronautics.

Welcome to Marisol KoslowskiAssistant professor Marisol Koslowski joins the ME faculty from Los Alamos National Laboratory. Her research interests include computational solid me-chanics, micromechanical systems, and nanostructured materials.

Dav

id U

mb

erg

er

William Peine operates hand controls for a surgical robot under development.

2

Spring/Summer 2006

and technology to make the most cost-effective and environmentally safe use of our most abundant fossil fuel resource—coal.

We are working on SO3 with encour-aging results, and I’m confident that in time we can conquer the mercury and CO2 emission issues. In fact, there is one plant being funded by several utilities that is designed for zero emissions. Investigating clean coal technologies today will protect our environment and pay extremely high dividends in the future.

Coal also offers a cost-effective way to substitute for natural gas and other petroleum products. The technology to convert coal to gas and liquids has been available for many years. Measured against past lower oil and gas prices, coal conversion was not competitive. However, now that these prices have moved sharply upward and will likely continue to go up, gasoline, jet fuel, diesel fuel, and pipeline-quality gas extracted from coal is a reality. I have often said that some things are just obvious. To me, coal gasification and liquefaction is compelling and obvious. A new industry is about to be born.

I’m proud to be a Purdue alumnus and proud that Purdue’s School of Mechanical Engineering has been a leader in coal research for decades and that it will continue to be. The Purdue engineers are known worldwide for solving grand challenges, and I know they will be major contributors to solving our energy supply problems.

—Ralph E. Bailey

people and our congressional leadership to understand that energy independence is an overblown myth, at least for decades to come.

The ever-growing demand for electricity, transportation fuels, home and industrial heating, petrochemicals, and industrial energy consumption urgently requires that we pursue all of our options. New sources such as solar, wind, biomass, and synthetics are all very important and fit into the supply base. However, for decades to come, the energy workhorses will remain oil, natural gas,

nuclear, and coal. We do not have to import coal, so we must do everything we can to make it a viable option, which means to consume coal cleanly and efficiently.

Many of our coal-fired power plants have been retrofitted with SO2 scrubber equipment and NOX reduction systems, and utilize newly developed combustion chemicals that have placed them in compliance with current clean air and emission standards, as well as improving efficiency.

The new generation of power plants that are in the development stage requires a large investment in research

Upon graduation from Purdue, I took a job as an engineer for Northern Illinois Coal Corporation (now Peabody) and have spent my entire life working in the energy business. From that early start I ultimately served as chairman and CEO of both a major U.S. coal company and a major U.S. oil company.

The mining and consumption of coal has always been a part of my life, and I have always believed in the potential for the increased use of this strategic natural resource. Because of this belief, I also focused on a concerted effort to make the mining of coal a healthy and safe occupation.

Coal, of course, is a vital energy source worldwide, and it is used in the production of about 50 percent of the electricity in the United States and about 70 percent of the world’s steel. Coal is abundant and widely distributed, and the United States has mineable reserves to last for two centuries or more.

Today, energy supply is a critical issue in the U.S. and other parts of the world. Fundamental to having a realistic understanding of U.S. energy supply issues is the need for the American

in my viewD

igit

al S

tock

Guest editorialist Ralph E. Bailey received his BSME from Purdue in 1949 and an honorary doctorate from Purdue in 1979. He was recognized as an Old Master and received the Distinguished En-gineering Alumni Award in 1976; served as chair of the President’s Council in 1978; was named a Sagamore of the Wabash in 1982; received the President’s Council Distinguished Service Award in 1986; and was recognized as an Outstanding Mechanical Engineer in 1991. Bailey began his career as a maintenance and construction engineer for Northern Illinois Coal Corporation in 1949 and retired as chairman and CEO of Conoco Inc. in 1987. Since his retirement, he has remained actively involved in energy exploration and production ventures. Bailey and his wife, Bettye, have endowed the Ralph and Bettye Bailey Professorship of Combustion in Mechanical Engineering at Purdue.

CLEAN COAL

3

Purdue Mechanical Engineering Impact

d e c i b e l sd e c i b e l s

cover

In the Middle Ages, amid bleating live-stock and humans haggling in the village marketplace, bell ringers, blacksmiths, and miners suffered what may be the first-documented cases of noise-induced hearing loss. And until recent decades, people in the modern world resigned themselves to noise as a price of technological progress.

With OSHA’s founding in the U.S. in 1970, however, noise in the workplace emerged as a legitimate health con-cern, resulting in hearing protection programs. Beyond the work setting, environmental noise—aircraft takeoffs and landings, trains rattling through tun-nels, cars roaring down freeways—has contributed to an aural assault that we’ve only now begun to realize we can combat.

“Noise is taking its toll,” says Patricia Davies, director of Purdue’s Ray W. Herrick Laboratories and a professor of mechanical engineering. “Noise adds to our stress level, and therefore there are implications for human health and well-being.”

Just how human perception of sound varies from one person to another, and just which characteristics of sound con-tribute to “noise,” or undesirable sound, aren’t fully clear, but a number of prob-lems are.

In addition to the most obvious—hear-ing loss—noise interferes with the per-formance of complex tasks, those that require sustained attention to detail, attention to several cues, or large work-ing memory capacity. It disturbs sleep, and some sounds can lead to sustained increases in blood pressure. Noise may also contribute to aggressive-ness. In the classroom, it can impede learning. (One study in the Journal of Environmental Psychology compared children’s reading ability in a school sited next to a train track. Children in classrooms alongside the track showed poorer performance than those across the hall.)

The problem has cost a lot of money thus far. In the U.S. aviation industry alone, engine manufacturers, along with

NASA, have spent $5 billion to make commercial aircraft quieter. Another $5 billion has been spent on remediation efforts in residences near airports—and still airport noise ranks high as an envi-ronmental concern.

At the Ray W. Herrick Labs, Davies and other experts in environmental noise, product noise, noise control, and sound perception form a premier group that studies how to reduce noise in the environment.

She and mechanical engineering pro-fessor Bob Bernhard, Purdue’s associate vice president for research, have recently been appointed to the National Academy of Engineering’s project “Technology for a Quieter America”—a comprehensive review of environmental noise (as well as product noise), with the goal of quanti-fying the problem and recommending solutions to Congress and governmental agencies.

Following, a look at cutting-edge re-search taking place under the roof of Herrick’s red barn.

Planes, trains, automobiles—they all make noise, and they all provoke complaints from an increasingly stressed-out citizenry. At Herrick Labs, researchers in

environmental noise are at work to quiet the urban soundscape.

Dig

ital

Sto

ck

4

Spring/Summer 2006

Aviation Noise: Rattle and BoomNoise pollution by aircraft can cause a range of disturbances, from a low- frequency rattle to sonic booms. (The latter are rarely heard since the 1970s ban on supersonic commercial flight across the U.S.) Each aircraft design produces its own signature sound, and the sound characteristics affect how the sound is perceived. What people do, where they live and work in relation to a plane’s flight path, their economic class, and even the political climate also affect perception of aircraft noise.

The FAA/NASA/Transport Canada Center of Excellence (COE) for Aircraft Noise and Aviation Emissions Mitigation counts Purdue as a participating mem-ber. Researchers in the Herrick Labs, along with their counterparts in Aviation Technology and Health Sciences, are pursuing a number of projects through the COE to create new, more unified noise metrics that go beyond a simple measurement of decibel level and that can contribute to decisions on aircraft design, airport operations, and land-

use management.“As scientists, we are designing math-

ematical models that can be used to predict perception of noise attributes, annoyance, and complaint levels,” explains Davies, whose expertise is in sound quality and metrics. “These models can be used with sound source and propagation models to simulate the impact of changes in airport operations and of changes in aircraft-noise signa-tures and thus can help in the planning of different patterns of land usage.”

Evaluating the relationship of airport noise to physiological responses, cog-nitive performance, and sleep quality will be part of COE researchers’ future efforts. In a related COE project, Davies is working with colleagues at Penn State and NASA to evaluate the characteris-tics of sonic booms and investigate the validity of using simulators to study hu-man response to these types of sounds. Manufacturers are predicting that they will be able to make low-boom aircraft, but the question is how low, and which kinds of booms would the public find

acceptable? Determining those an-swers could lead to setting noise sig-nature goals for a return to commercial supersonic flights cross-country.

Colleagues Bob Bernhard and Luc Mongeau are examining how to predict and mitigate low-frequency aviation noise—the 50- to 200-Hertz rumble or rattle from the local airport that shakes a homeowner’s china in its cabinet. “It’s a very tough thing to control,” says Bernhard. “What normally saves us is that the ear isn’t very sensitive in this range. So if you build your strategies for aircraft noise control based on the sen-sitivity of the human ear, we wouldn’t be too concerned about this problem.”

It’s the propagation of the sound that’s the concern. For example, an aircraft’s thrust reversers, engaged dur-ing landing, can propagate sound and vibration miles away. “That sound can do things like shake walls and cause rattle,” says Bernhard. “We’ve been able to use simple models to explain what’s going on and to extract how you suppress rattle.” The Herrick research-

5

Purdue Mechanical Engineering Impact

writing letters to their congressmen. There’s now more investment in envi-ronmental acoustics, and it’s a growing field here.”

Li’s interest in urban noise—how sound moves through cities—con-tributes not only to the FAA Center of Excellence work mentioned earlier, in determining how low-frequency aviation noise propagates in urban settings, but also to the study of how noise is gener-ated when trains pass through tunnels.

“In cities, you have ‘canyon streets,’” he says. “The sound’s propagation is affected by the tall buildings on either side of the street.” Tunnels are like can-yon streets with a top supplied, and similar physics apply to these long en-closures.

“We’re concentrating on how to re-duce noise levels inside a railway tunnel by using innova-tive surfaces,” he continues. The wheels of an advancing train

ers have sound-insulation recommen-dations in place that window and door manufacturers can follow to address the problem.

Given our dependence on air travel—the past 35 years have seen a six-fold increase in the mobility provided by the U.S. air transportation system, accord-ing to the FAA—a lot’s at stake in get-ting aviation noise reduced. The number of Americans exposed to airport noise levels of DNL 65 (65 decibels averaged over a 24-hour period) has plummeted since 1975, from 7 million to about half a million, yet projects to build more air-ports, or to expand existing ones, still run up against civic opposition, and projects across the country are scrapped.

“Just five or so airport expansions or new construction projects happened in the last 10 years at the country’s 30 busi-est airports,” Bernhard points out. “The biggest constraint on the growth of the U.S. aviation industry in this country is noise.”

Trains in TunnelsHaving lived in both London and Hong Kong, Kai Ming Li has experi-enced some of the noisiest locales on the planet. Moving to Purdue and the comparative quietude of West Lafayette, Indiana, in 2005, the me-chanical engi-neering professor still continues his research interest: urban noise and the prediction and abatement of tran-sit noise.

“Transit noise is becoming more and more of a problem in the United States,” says Li. “As the popula-tion grows and people become more informed, they’re complaining more,

hammering on the track can produce an 80- to 90-decibel sound that’s virtu-ally unbearable to passengers inside.

Li is exploring the use of hard, nonfi-brous rough surfaces inside tunnels. “A small noise will reverberate in the typi-cal tunnel, and there’s usually limited absorption because the sound bounces around,” he says. The surfaces he’s investigating produce a diffused sound field that yields significantly lower noise levels—good news to the ears of American commuters, who make some 423 million trips by train each year.

Road Noise: Turning Down the VolumeAt Purdue’s Institute for Safe, Quiet, and Durable Highways (SQDH), road noise is the theme, and since SQDH’s creation in 1999, Purdue—and Herrick

Labs—have emerged as a national leader in miti-gating the problem.

“Traffic noise is a per-sistent long-term en-vironmental effect of highways,” says institute director Bernhard. “The public’s annoyance with highway noise had been artificially suppressed by the myth that there aren’t any solutions. When peo-ple complained about the interstate next door, or the

beltway running beside their house, the local transportation agency would say nothing could be done.”

The mechanics of noise control: For Purdue engineers, reducing sound levels means go-ing on-site, as at this train tunnel (above), and to the lab (above right and facing page).

Imag

es

cour

tesy

of K

ai M

ing

Li

6

Spring/Summer 2006

Along with research, Herrick is mak-ing a name for itself in education and outreach, hosting road-noise and na-tional strategic planning workshops that draw participants from transportation agencies all over the country. Bernhard himself travels extensively to co-teach “Tire-Pavement Noise 101” to state departments of transportation. Says Herrick director Patricia Davies, “Bob has taken a true leadership position in teaching fundamentals and bringing the latest sound metrics to that community. This outreach and the research of Bob and his colleagues has significantly en-hanced Herrick Laboratories’ reputation as a world-class institution in road-tire noise research.”

Herrick as Living LabAlthough environmental noise concerns the exterior soundscape—the sym-phony, or cacophony, of natural and human-produced sounds in an outside location—Herrick researchers are, not surprisingly, interested in interior noise as well. This interest complements the research of Herrick’s Yan Chen and Jim Braun on thermal comfort and indoor air quality.

Experts at Herrick Labs (and the School of Civil Engineering) began looking at noise and vibration control, pavement construction, and the dynam-ics of tires rolling on roadways—and met with a “rising tide” of public interest, Bernhard says.

“About the time SQDH started, Arizona discovered that one of the pavement designs that they had been using to avoid cracking in asphalt pave-ment was quiet, and citizens of Phoenix began to demand that that pavement be put down on all the interstates in the city,” he says. Add high-profile road-construction projects in Detroit and California, and “all of a sudden,” he continues, “people are clamoring for answers.”

Herrick is uniquely positioned to con-tribute, thanks to faculty expertise and a one-of-a-kind apparatus that Bernhard conceived and had constructed for testing how tires perform on various kinds of pavement (see “Rubber Meets Road,” page 9).

It may come as a surprise, he says, that most of the acoustical pollution from cars doesn’t come from engine noise but from the interface of tires and road surfaces. Researchers including colleague Stuart Bolton are exploring the physics of pre-cisely how the tire vibrates and ra-diates sound and are developing sound visualization techniques to develop a greater understanding of what is happening in a real tire and to validate their models.

“Vibration of the tire carcass can radiate sound the way a speaker radiates sound,” says Bernhard. Herrick researchers have used laser Doppler vibrometry with an electromagnetic shaker, which send vibrations of various intensities through a tire. Reflected light from a helium-neon laser records how these vibrations propagate.

“It’s like dropping a pebble in a lake and watching how the ripples move away,” says Bernhard. “We study which waves propagate more than others, what radiates sound and what doesn’t.”

unique challenges for noise control en-gineers. Noise in hospitals, for exam-ple, can lead to increases in recovery times, as reported in the Journal of the Acoustic Society of America, but many acoustic materials that are commonly used in buildings have “pockets” in which bacteria can breed—a great challenge for researchers like Herrick’s Bolton, who studies design and optimal application of sound-attenuating materials.

Herrick Labs’ upcoming renovation and expansion, planned to begin in 2007, is a prime opportunity to con-figure the facility as a “living laboratory” for exploring com-bined acoustic and thermal comfort, says Davies. “As we renovate, we would like to build the administrative wing as a test bed that’s exten-sively instrumented to evalu-ate those properties, as well as energy usage, air qual-ity, lighting, communication,

security, safety, productivity, and other factors.” It’s a step toward making high-performance buildings the rule rather than the exception.

And that step, combined with the ma-jor strides that Herrick has taken in ex-terior noise control, promises a quieter, more peaceful environment for us all.

—Lisa Hunt Tally

Pianissimo to FortissimoSample noise levels measured in dBA.*

0 Threshold of human hearing 20 Whispering at five feet 60 Normal conversation 70 Freeway traffic 80 Doorbell 90-95 Level at which sustained exposure may lead to hearing loss 95 Subway train at 200 feet 120 Ambulance siren 140 Threshold of pain 150 Jet engine at takeoff 170 Shotgun

*A-weighted sound pressure level. Taken from Beranek, Noise and Vibration Control, INCE, 1988.

7

Chen and Braun have spearhead-ed multidisciplinary research efforts focused on designing buildings to increase productivity, comfort, and health—efforts that involve simultane-ous thermal, acoustic, and air quality control. Environments such as aircraft and automobile interiors, hospitals, and schools come with constraints that pose

Purdue Mechanical Engineering Impact

When Purdue first opened its doors on September 16, 1874, the fledgling university counted six instructors and 39 students. Now the main campus has gown to approximately 1,750 faculty and 38,000 students, on the shoulders of many great individu-als. Dean Potter was one of the greatest.

A graduate of the Massachusetts Institute of Technology (BSME 1903), Andrey Abraham Potter joined Purdue in 1920 as dean of engineering, serving as acting president in 1945 and concluding his tenure as dean in 1953. He gave freshman lectures about the role of engineers in society, opening with the line, “We must learn zee mother language” delivered with a thick accent. He reminded students that an engineer must be-come a good citizen of the world and develop interests outside the profession.

Books have been written about this Russian immigrant documenting his public strengths: great teacher of students at all levels, national leader of important engineering societies (known as the “Dean of Deans of Engineering”), and builder of Purdue’s world-class College of Engineering. Not so well known are his wonderful personal qualities: friendly engage-ment with students, devotion to his family, frugality in his per-sonal life, and generosity toward his family and Purdue. These qualities came through to me from his great-niece, from indi-viduals who knew him in Lafayette, and from documents sent to me by his close friends.

As a student, I recall eating dinner with Dean Potter in the residence hall where I lived. He was a particularly gracious guest, at ease with students, with a very friendly wisdom that the students appreciated. Some glimpses of this most singular man:

• In 1928, Maurice Zucrow was granted the first Purdue PhD, in mechanical engineering. Dean Potter recruited Zucrow, and they became fast friends. After arriving here, Zucrow married a local woman, and they soon had a baby. A few months after the baby’s arrival, Dean and Mrs. Potter called on the proud parents. The baby was sitting on the floor playing with a large rubber ball. Dean Potter immediately got down on his hands and knees and rolled the ball back and forth with the baby—who was without a diaper. Only Dean Potter could play ball with a bare-bottomed baby!

• Potter met a young man working on the Canadian railroad and was impressed with his ability. The man asked if he could come to Purdue. Potter agreed, but the University would not admit him because he did not have a high school diploma. Potter went to the president to plead his case. President Elliott said no. Then Potter said, “I will

give you my letter of resignation that you can accept if he doesn’t graduate.” Elliott accepted the offer. The man enrolled and did graduate. He then went on to become the president of the Canadian National Railroad.

• Dean Potter’s mother, sister, nieces, and nephews lived in Boston. On a trip there, he insisted on buying his great-niece a canary as a gift. He invited her to walk to the store with him, about a three-mile trip. After the purchase, the niece expected to take the streetcar home along Beacon Street, saying she could not carry the cage all the way back. Potter understood, reached in his pocket, gave her a dime for the streetcar fare, and walked back by himself. Dimes were not to be wasted on frivolous things like streetcars when you could walk! During the Depression he sent home $50 each month, an amount that supported the Boston family during a very difficult time.

After his retirement, Potter gave $100,000 to Purdue, saying that this sum represented all the salary money he had been paid in his 33 years at the University. He died in Lafayette in 1979, at age 97.

—Henry H. Hirschl

Andrey Abraham Potter: The Man for All ReasonsAlumnus Harry H. Hirschl (BSME ’47) remembers Purdue’s “Dean of Deans.”

“As dean,” A. A. Potter wrote to Purdue president W. E. Stone in 1920, “I should be honored to devote my time to close contacts with my colleagues and students in the interest of enhancing Purdue’s standing as a leader in engineering education and research.” Potter, above right, is shown here with Purdue president Edward Elliot (above left) and Purdue industrial engineering professor Lillian Gilbreth (above center).

retrospective

8

Spring/Summer 2006

Using Herrick Labs’ mighty tire-pavement testing apparatus—the world’s only such device—an ME doctoral student investigates the fundamental mechanics of road noise.

It’s the first step toward silencing the dull roar.

By Will Thornton’s account, some 2,630 linear miles of noise walls have been built in the U.S., at a cost of $1.5 million or more per mile. And they’ve done very little good.

“They’ve been built along highways and roads to attempt to block the path of the noise,” says the Purdue doctoral student in mechanical engineering. “So the concern over road noise isn’t new. What we’re attempting to do at Herrick Labs is to get rid of the noise problem by eliminating the source. We believe that this is far more effective and cer-tainly more cost-effective than band-aid solutions like noise walls.”

Pursuing research sponsored by the American Concrete Paving Association (ACPA), Thornton is looking to identify Portland cement concrete paving textures that are quiet. A second- generation Herrick student—his father also studied acoustics, receiving a

master’s and doctor-ate from Purdue—Thornton notes that in the field, industry has relied on anecdote and custom rather than rigorous test-ing to determine how to build quiet roads. “The realization that the problem occurs at the tire-pavement interface and that we can come up with engineered solutions to the problem is new,” he says. “What we are attempting to do is to design away noise that people previously believed

they just had to live with. The public is becoming aware that something can be done.”

Thornton is investigating how different texturing, or grooving, techniques ap-plied to pavement affect noise produc-tion when tires pass over the pavement. “Industry would like a magic bullet—one specific texturing pattern that will work—but it’s complicated,” he says. “It’s an optimization problem. Roads need to be safe, durable, and economi-cal.” Under those constraints, how do you reduce noise?

In a Herrick lab, Thornton has put the problem under a microscope—or, more literally, microphone. Using ACPA- prescribed concrete mixtures, Thornton and his colleagues create road sam-ples that are forklifted into place on an immense tire-pavement testing appa-ratus and textured according to various specifications (concerning the depth

and width of the grooves, for example). With transducers, or microphones, in place for capturing noise and acceler-ometers in place for registering vibra-tions, the apparatus can accommodate as many as 12 different arc-shaped samples at once as a rubber tire re-volves around the doughnut-shaped configuration. The setup is unique in the world in using real, not synthesized, pavement for testing.

Employing different microphone posi-tions and different loads, Thornton runs any given tire at 10, 20, and 30 miles per hour. The data gathered at the ap-paratus is sent wirelessly to a computer in an adjoining office.

So just what makes some pavements noisy? “We know that certain positive textures—road surfaces in which a pat-tern is raised up—tend to create noisy surfaces,” says Thornton. “But we’re early in this work. There are several noise-generation mechanisms occur-ring at the tire-pavement interface, and it’s difficult to determine how any one mechanism affects the overall noise.” After compiling and analyzing data, he’ll proceed with drawing conclusions and making recommendations.

“In the field, testing such as this could take years and would be very expen-sive,” says Thornton, “and the ability to explore innovative concepts would be very limited. At Herrick, we can con-duct this testing in a highly controlled environment at a small fraction of the cost, both in time and money, of field testing. We’re also freed from many of the practical constraints of constructing pavements in the field and can explore innovative and novel solutions to the noise problem.”

—L.H.T.

John

Und

erw

oo

d

Revolutionary: On Purdue’s 38,000-pound, 12-foot-diameter tire- pavement testing apparatus, an automobile tire revolves at 10, 20, and 30 miles per hour. ME student Will Thornton captures the noise produced.

Rubber Meets Road

up close: students

9

Ben Hillberry and Eric Nauman

Purdue Mechanical Engineering Impact

up close: faculty

Building a Better Back (Cervical to Lumbar)

Your spine is one of Mother Nature’s most impressive feats of engineering: strong and flexible, enabling you to shake your head (all 15 pounds of it) in defiance or to support half the weight of that upright piano your friend needs

hauled up a flight of steps.When it’s damaged, though, the

spine can benefit from human exper-tise, and Purdue engineers are at work

to provide that. Ben Hillberry, a professor of mechanical and biomedical engineering, leads

a team of mechanical and bio-medical engineers at Purdue who have developed specialized hy-

draulic machines and software to help industry create better

implants for people suffering from spinal injuries, disease, and age-related wear.

In the basement of the Mechanical Engineering Building, the team is using finite-element analysis to

predict the strength and

other properties of the implants being tested. Armed with that knowledge, in-dustry can proto-type implants, which Purdue engineers can then attach to spines from cadav-ers and test mechani-cally in the Purdue Spine Simulator. This hydraulic machine, designed by alumna Beth Galle (MSME 2004 and currently

a doctoral student in ME at Purdue), re-creates the spine’s natural twists, bends, and turns, demonstrating how the implants stand up to everyday de-mands.

A cervical fatigue tester designed by the Purdue engineers is used specifi-cally to test ball-and-socket-like im-plants for the cervical spine (the neck region). “There is much more move-ment in the cervical spine than in the lumbar portion, so what we are primar-ily testing with this machine is how well implants will stand up to wear over a period of about 10 years,” says gradu-ate student Shreekant Gayakar.

For implants to be approved by the Food and Drug Administration, says Hillberry, “it has to be shown that they can last 10 million cycles, or 10 mil-lion movements, which translates into about 10 years of living. Our goal is to complete 10 million cycles over a four-month period.”

Whereas wear is the primary con-cern in the cervical spine, damage

from injury and disease are the biggest problems in the lower back, or lumbar region. “Arthritis in your spine is awful,” says Eric Nauman, an assistant pro-fessor of mechanical and biomedical engineering. “It’s one of the worst kinds of skeletal degeneration you can get. Basically, the medical community is try-ing to create new devices that dupli-cate the spine’s natural motion instead of immobilizing the damaged area.” Researchers are using the Purdue Spine Simulator to test implants that re-place arthritic “facet joints.”

The Purdue team also is working with Archus Orthopedics Inc. to develop mathematical simulation tools that will allow the accelerated development of next-generation implants.

“Future designs may ultimately be used in conjunction with total disk replace-ments, allowing the restoration of function at any vertebral level in the spine, much like total hip and total knee replace-ments currently achieve,” says Jorge Ochoa (MSME ’87, PhD ’91), Archus Orthopedics’ vice president of R&D and chief technology officer.

—Emil Venere

Using spines from human cadavers, Purdue engineers are developing machines and software models that will help create better implants for aching backs.

Blake Powers

Election as Society Fellow Caps Hillberry’s CareerSet to retire at the end of this academic year, Ben Hillberry gained the distinction this past March of induction as a fellow of the American Institute for Medical and Biological Engineering. “My peers are the ones recognizing me, so that makes this award very meaningful,” says the professor of mechanical and biomedi-cal engineering, who is known for his work in biomechanics and the fatigue and fracture of materials. Also a fellow of the American Society of Mechanical Engineering and the American Society for Testing and Materials, Hillberry has been at Purdue since 1967.

Bla

ke P

ow

ers

10

Spring/Summer 2006

up close: alumni

Clean Air: Cecil F. Warner Led the Way

When Cecil F. Warner died on December 8, 2005, Purdue lost a beloved alumnus, a revered faculty member, an outstand-ing community volunteer, and a leading researcher and educa-tor on the origin and control of air pollution.

Warner received his BSME in 1939 and his PhD in 1945 and devoted his life to conducting research and mentoring stu-dents. Last June, the School of Mechanical Engineering and Warner’s family surprised him with the announcement that the conference room at Zucrow Laboratories would hence-forth be known as the Cecil F. Warner Conference Room. More than a hundred friends, including astronaut Jerry Ross, a graduate student of Warner’s, were present to honor this pio-neer in air pollution control.

Although air pollution had been a concern in London, England, as early as 1272, it did not become a national concern in the United States until the 1950s, when the Air Pollution Control Act was enacted. A succession of leg-islation followed, including the Clean Air Act in 1963, the Motor Vehicle Air Pollution Control Act in 1965, the Air Quality Act in 1967, and the Clean Air Act amendments in 1970.

Warner’s landmark contribution was the publication, by Prentice Hall, of the first edition of Air Pollution, Its Origin and Control. The third edition of this classic air pollution text, co-authored with Kenneth Wark and Wayne T. Davis, came out in 1998.

Air Pollution, Its Origin and Control provides engineers and scientists an introduction to this ever-more-relevant subject. Known for its detailed devel-opment and application of equations, the text is not simply a handbook but, rather, emphasizes an understanding of the relationship between sources and control of air pollution. Warner and his co-authors present information on the effects of pollutants on health and welfare, the laws and regulations that have been passed in efforts to improve air quality, the modeling of atmospheric dispersion of pollutants, and approaches to the control of emis-sions (from both stationary and mobile sources). The third edition covers the

latest regulations, including the Clean Air Act Amendments of 1990. The latest standards for ambient air quality and emission also are included.

Purdue alumni like Cecil F. Warner have been meeting society’s grand challenges head on for more than 100 years. Through Warner’s legacy of scholarship, new generations of en-gineers are equipping themselves to solve the challenges of tomorrow.

—Keith H. Hawks

This Purdue alumnus wrote the book on air pollution control.

Keith H. Hawks (BSME ’64, MSME ’66, PhD ’69) is assistant head and associate professor in Purdue’s School of Mechanical Engineering. His interests include power plant systems, pollution control, and energy management.

11

Purdue Mechanical Engineering Impact

Purdue’s Distinguished Engineering Alumni Convocation honored Roman Krygier on March 3, 2006, for his “outstand-ing leadership and vision in global automo-tive manufacturing and management.”

exterior moldings, inside trim, and exterior trim,” he says. “The relationship part of the business was really broadened, and our interface with the engineers who designed the ve-hicle was much more involved. My engineering background and degree made me comfortable in those relationships.”

Krygier’s next promotion, to general manager, brought him responsibility for all of Ford’s North American assembly plants, stamping plants, and manufacturing engineering. At that time, the automaker embarked on the Ford 2000 initia-tive, a project for globalizing and standardizing processes and operating methods. “That was a time of change for the company, and the project had a lot of visibility,” says Krygier, whose experience and expertise broadened, with involve-ment in Europe and Asia. As a result of Ford 2000, he led the development of the Ford Production System, which defined a common way in which Ford facilities were to operate around the world.

In the position from which he has just retired—group vice president for global manufacturing—Krygier oversaw the de-velopment of Ford’s 3.5-liter V-6 engine, to be launched in 2006. The Lima, Ohio, plant that builds the new engines re-flects Ford’s flexible manufacturing approach, incorporating common engine architectures, common manufacturing equip-ment, and CNC (computer numerical control) machine tools.

Flexible manufacturing in Ford’s assembly plants means that “we can deal with up to four models off a given platform, as well as different platforms using the same tooling and facilities,” says Krygier. “This allows us to respond to lower incremental volume, or come up with unique vehicles off our base platforms.”

In addition to spearheading Ford’s flexible-maufacturing systems, Krygier served as the company’s executive spon-sor for worker safety, overseeing a more than 90 percent im-provement in safety statistics during the past six years, and he gained distinction over the course of his career as an advocate of employee involvement and as a coach and mentor to other Ford employees. For the 2003 United Auto Workers (UAW) contract with Ford, Krygier served as lead negotiator, along with Ford’s vice president for labor relations. “My experiences were always positive and effective with the UAW,” he says. “Labor relations and involvement with the UAW were part of my fabric as I grew up in the business.”

—L.H.T.

In 1964, Ford Fairlanes, Galaxies, and Thunderbirds filled American highways, and a classic—the Mustang—was born.

That same year, Roman Krygier joined the automotive giant as a trainee foreman

at its Chicago Stamping Plant, beginning a 42-year career

that would help usher in Ford’s flexible production oper-ations and cul-minate with his post as group vice president of global manu-

facturing.The son of a jour-

neyman tool-and-die maker, Krygier grew up in

Thornton, Illinois, and enrolled in Purdue—the first member of his family to attend col-lege. “It was challenging,” he recalls. “Being the oldest son and oldest grandson, I was always concerned about making sure I would gradu-ate. I took it seriously.”

With his bachelor’s degree in mechanical engineering

from Purdue, Krygier started at Ford, completing two years of rotational assignments. “I always had a bent for manu-facturing operations,” he says. Nine years into his career at Ford, he accepted the company’s offer for him to study at MIT as a Sloan Fellow and earn a master’s in the science of management.

Krygier’s move to the Buffalo (New York) Stamping Plant in 1977 as plant manager marked a turning point. After leading a turnaround of the Buffalo plant, he was promoted to stamp-ing business manager and then operations manager.

In 1992, Krygier had the opportunity to learn the assembly side of automotive manufacturing when he became Ford’s assembly operations manager. “You had to deal with all your supply base for engines, transmissions, radios, stampings,

alumni news

Cou

rtes

y Ro

man

J. K

rygi

er J

r.

Roman J. Krygier Jr.: Built for the Road AheadIn a career spanning four decades, this 2006 Distinguished Engineering Alumnus

helped bring innovation to Ford Motor Company.

12

alumni news

Purdue and BeyondThis Boilermaker’s college experience launched a career with NASA.

unique, like “Machine-Gun” Geiger.Now, my only nightmares about Purdue

are of losing my schedule and not knowing which Quonset hut to go to next. The rest are good memories, but I also wonder, what if just one of those circumstances hadn’t gone the way it did? How could I have planned ahead for that? But if someone asked me if I would do it again, I would have to say yes, and in the same way.

—David G. Evans (BSME '52) There were two other “D. Evanses” in some of his classes,

Evans recalls, “and that’s how we decided to sign our test papers.”

Father, son, and alma mater: Norm Gertz (BSME ’55) and son Tom Gertz (BSME ’80, MSIA ’87) stopped by Mechanical Engineering’s booth just before Homecoming last year and found themselves the lucky winners of club seating for two. “The seats to the game were awesome,” Tom recalls, “but we won’t talk about the final score!”

The beginnings of maturity started for me 57 years ago at Purdue, and in retrospect there was no way I could have pre-dicted or planned my life’s course. So much was the result of luck, chance, or circumstances.

My first shock was learning I was 10 years younger than my class average. We high school graduates were outnum-bered by World War II veterans. They knew why they selected Purdue, were driven to make up for lost time, and had respon-sibilities—all the things I lacked. This, plus Purdue’s system of grading on a curve and allowing only three grammatical errors a semester, resulted in four years of anxiety for me.

The saving grace was learning how to study, but that came just as the Korean War broke out, and I faced losing my new skill to the Army. Then luck took over. I had my choice of two lines to stand in, one in front of a colonel who disliked college students, sending every one to Korea—and without training. The other line’s colonel, the one I picked by chance, was just the opposite.

Freshman chemistry was the flunk-out course, but a later course in fluid mechanics became my nemesis. After I graduated, the NACA [to become NASA] Propulsion Lab at Cleveland hired me, and the real world began. I worked in the same group as a future academician, one who wrote two books on fluid flow and later became president of Purdue: Art Hansen. But the war was still on, and I was being deferred. I quit NASA and went to war. But to my surprise, I was as-signed to an engineering office and a drafting board—the epitome of experience for a new engineer back then.

Later, with a clear conscience, I went back to NASA and my fluid mechanics nemesis. Redemption came in the first year of the space program: 1959. I went through suborbital astro-naut training and then oversaw experiments to find the effects of weightlessness on two-phase flows in Rankine systems (and on me). Power generation in space depended on it. I had more time at 0-G that year (and sick leave) than anyone until John Glenn’s three-orbit Mercury shot three years later. But my nemesis was over, and the aerodynamics of turbines and the thermodynamics of heat engines became my career. Then, six years before retiring, I became a chief engineer.

If I hadn’t found some semblance of fun during this journey, I would have given up, or worse. But, on the other hand, it didn’t take long to get to like President Hovde. He was Purdue for us. Many ME professors were also memorable for their true caring, such as Bill Miller, Dave Clark, or those who were

Spring/Summer 2006

13

campaign impact

Purdue Mechanical Engineering Impact

$132 million down. $18 million to go. One year left, and the clock is running!

That’s a summary of the Mechanical Engineering portion of the $1.5 billion Campaign for Purdue.

It’s exciting to report that progress is being made on the Roger B. Gatewood Wing of the ME Building. The University will be doing some tunnel and util-ity work near our expansion site, and we will be able to piggyback on that project to save some money and be ready to build when we receive the $17 million being requested from the state. Construction costs have increased substantially since the original project estimates, and we will be asking the state to cover some of that increase. We project that further increases in con-struction costs will require that we either raise an additional $4 million in private

One Year and Counting

funds or reduce the size of the building. The Ray W. Herrick Laboratories, an

institution dedicated to graduate edu-cation and engineering research with emphasis on technology transfer to in-dustry, is the last capital project for the ME campaign. The Laboratories have established an outstanding interna-tional reputation for research in thermal systems and noise and vibration con-trol and are particularly valued for their contributions to the automotive and heating, ventilating, and air-conditioning industries.

The research at the Laboratories is as relevant today as it was at its incep-tion nearly 50 years ago, and responds to global needs in the areas of energy, the environment, and sustainability. The Laboratories are in dire need of expan-sion and renovation to meet the grand challenges of tomorrow.

The Herrick project will include the construction of a “Living Laboratory,” which will serve as the Laboratories’ administration wing (student, faculty, and staff offices; conference rooms; etc.) and will be configured to serve as a test bed for advanced building concepts. The Living Laboratory will facilitate translation of fundamental ad-

vanced buildings research into robust working technology that will be used in commercial and residential buildings to increase the comfort, health, and pro-ductivity of building occupants.

In addition to needing money for buildings (the Herrick project will be financed completely with private dona-tions), we want to increase the number of endowed professorships to attract and retain the best faculty. Purdue’s Board has facilitated this with a limited number of “Goodwin Matches.” As I write this, there are still a few matches available—you contribute $750,000 over three years, and your gift is matched with another $750,000 to en-dow a $1.5 million professorship. You name the professorship, designate the general aspect of ME you want it to support—and impact ME in perpetuity.

This is a great time to be a Boilermaker and a great time to step forward to help smooth the road for the Boilers of the future!

—John Sanderson Director of Development

Our expansion is in sight: We’re getting ready to build the ME Building wing, which will transform artist’s renderings—here, for the Tech Atrium, a collaborative learning class-room, and the Product Engineering and Realization Laboratories—into reality.

Arl

ine

Mee

han

14

impact interact

Spring/Summer 2006

Plumber PuzzlePut your mind to this puzzler, and e-mail your solution to Cynthia Dalton at cdalton@purdue.edu. Readers supplying correct answers will be named in the Fall 2006 issue of ME Impact.

Make a square (or rectangular structure) that is flat in one plane using ordinary standard plumbing pipe. The four pieces of pipe are to be identical in all char-acteristics, and also the four elbows are to be identical in all characteristics. For the pipe, the right-handed male thread is to be used. For the elbow, the matching right-handed female thread is to be used.

You can easily assemble each of the elbows onto the pipes until you get to the last joint. At the last joint you need a left-handed thread to get it together. This is the puzzle.

—submitted by Ben Hillberry, professor of mechanical engineering

Coming UpJuly

15-16 Herrick Laboratories Short Courses

17-20 International Refrigeration and Air Conditioning Conference;

International Compressor Engineering Conference

September 2 Football: Purdue vs. Indiana State

9 Football: Purdue vs. Miami, Ohio (Family Day)

16 Football: Purdue vs. Ball State

18-22 Global Engineering Week

23 Football: Purdue vs. Minnesota (Homecoming)

24 ME Awards Convocation

October 21 Football: Purdue vs. Wisconsin

26 Outstanding Mechanical Engineers Award Ceremony

28 Football: Purdue vs. Penn State

November 18 Football: Purdue vs. Indiana

Jeffrey Henkle Solves “Weightlifter Puzzler” (MEmo 2005)

In our last issue of ME Impact, we ran the solution to the “Weightlifter Puzzler”

@ It’s Your Turn@Please help us keep up with your achievements and career successes. E-mail us at mealumni@purdue.edu.Include your contact information, degree year, and the news—civic achievement, board memberships, professional honors, career activi-ties—that you’d like to report. Alumni news will be published in future issues of ME Impact.

that had appeared in MEmo 2005, but we neglected to credit alum Jeffrey

Henkle (BSME ’97) with solv-ing the problem of the Olympic weightlifter who had ruptured his patellar tendon while execut-ing a clean-and-jerk maneuver. The question: Determine the forces exerted on the patellar tendon.

Henkle writes, “I solved this using Engineering Equation Solver, which we used in un-dergrad for thermo problems and other classes 10 years ago. It was so useful that I con-vinced my employer to buy it a few years ago. It’s so nice to enter n equations with n un-knowns instead of trying to ma-nipulate the equations to enter it all in Excel.” His final answer: Gy = 2,695N.

15

apertureThe device, a vacuum pressure gauge, operates on the principle of gaseous ionization. The glowing filament produces electrons, which are accelerated until they collide with gas molecules and ionize a portion of them. The gauge then measures the ionic current, which is related to the vacuum pressure. Purdue mechanical engineering professor Tim Fisher, who studies electron emission phenomena in high-vacuum environments, uses the gauge to ensure that his research group’s work is operating at low pressure. Applications of the research include flat-panel displays, radio frequency electronics, and direct energy conversion processes.