From the Princeton Weekly Bulletin, May 12, 1997

Building a better hairdryer

Design competition wins students a trip to Bangkok to present plans

By Caroline Moseley

An innovative hair dryer design won five of Princeton's nascent engineers a trip to Bangkok, Thailand in March. After competing against six other teams of students in a course called Engineering Design, winners Lina Jin '97, Andy Johnson '98, Matt Nuffort '98, Meeko Oishi '98 and Eric Young '98 were invited by the electronics firm Manica Corp. to present their design to company executives at headquarters in Bangkok.

The students were accompanied by Associate Professor of Mechanical and Aerospace Engineering Daniel Nosenchuck, their instructor in the course, and graduate student teaching assistant Clay Gabler.

Nosenchuck, an expert in fluid mechanics who consults for Manica and several other electronics firms, set the class the task of "designing a quiet hair dryer" last fall. He asked them to make it "a little more powerful than current models--2000 watts instead of the typical 1800-1850 watts--and to aim for an acoustic level of about 60 decibels, which exists in an ordinary office with no machines clattering." (The average dryer at the present time, he says, is about 80 decibels.)

Manica's CEO and chief engineer visited campus to judge the competition in January.

Come spring break, the winning group set off for the Far East. Their first stop was Hong Kong, where they visited Manica's purchasing department and toured the city.

Manica's director of purchasing explained to the students how "it's more efficient to do purchasing in a free trade port, even if it's not where you do your manufacturing. That's why U.S. companies often can't compete with countries in East Asia that are purchasing through places like Hong Kong," Nosenchuck says.

"I could make a difference"

In Bangkok, the Princetonians sat down with Manica's CEO, design engineers and top level management.

Recalls Nuffort, "They more or less turned to us and said, 'OK, what are we going to do now? How are we going to take your design and create something manufacturable?'" It took a moment for the students to realize "they were looking to us for expertise. It put a real significance on the education I've received at Princeton that, even as a junior, I could make a difference to this company."

"Their people knew more about the practical aspects of manufacture than we did," Jin points out. "For instance, one of our ideas was rejected because it involved a component being subjected to extreme working stress, which would shorten the lifetime of the product--which wouldn't satisfy customers."

Still, says Johnson, "It was great to feel that we were of real value to a significant player in industry. Granted, we're only talking about hairdryers here, but I never thought I would be doing something like that at age 20."

Johnson's feeling that "I'll come out of Princeton knowing enough to make valuable contributions in industry" is one Nosenchuck aims to foster. Nosenchuck spent a summer as fellow at the Boeing Co. in Seattle that introduced him to "the workings of a very large company and its relation to what faculty and students here can do." He has made an effort to move the engineering curriculum toward courses that use modern engineering tools, such as computer aided design, engineering and manufacturing (CAD, CAE and CAM) and also "make students aware of the opportunities offered by global enterprise.

"Engineering is a profession," Nosenchuck asserts. "Engineers are meant to produce competitive goods and serve customers."

He himself dwells as comfortably in the academy as in the marketplace.

"What makes Princeton strong," he insists, "is the emphasis on fundamentals. Our students must know the principles of physics, math and chemistry to become engineers."

His design students start "with pencil and paper," he says. "Sometimes I let them use chalk on the board. But I ask them not to got to the computer until they think their design is going to work, a conviction that can only be based on first principles."

Team approach

Nosenchuck uses the team approach in his courses, because "no single individual could create a complex system in the time we have available," he says. "And team design is a regular procedure in industry. Why? Because the whole is greater than the sum of its parts; and you get the job done faster --which, in industry, translates to a competitive advantage."

According to Johnson, "Team dynamics were the key to our success in the hairdryer competition. On the design side, Eric and I were the dreamers and conceptualists; Matt, Meeko and Lina took care of the heavy analysis and theory. When things got bad, we all pulled together instead of going at each other's throats."

"A lot of advanced engineering went into designing the dryer shell, in terms of providing the right flow," Nosenchuck says. Air is a gas, he points out, that is treated like a fluid. The students performed simulations using computational fluid dynamics, and "they tried housings of various geometries, trying to ensure the flow didn't separate, which is very inefficient."

The students designed their dryers using ProEngineer, a CAD program that allows three-dimensional modeling.

"You can spin the design around, look at everything in 3-D, change the dimensions easily," says Nuffort. "Then you export those files to a manufacturing computer that starts with a block of plastic and cuts it according to ProEngineer's instructions."

So what's the secret of the Hairdryer of the Future? Unwilling to spill too many beans about a design that may be patented, Nosenchuck says only that "it uses multiple blower fans within the housing and a minimal number of structural components. Also, it provides a very low acoustic emission level with high flow rate."

Nosenchuck would like "all the design students to have the same experience Manica provided for those on the winning design team." He hopes to "institutionalize an appreciation of the connections between modern engineering design and global enterprise.

The unofficial University motto, he points out, "used to be 'Princeton in the nation's service.' Now, with the 250th Anniversary, the motto has been expanded to include 'the service of all nations.' What better way to honor that idea than to move students from the confines of the campus to the broader world beyond, to establish them in service throughout their professional careers?"