Princeton Weekly Bulletin February 2/15/99
He's no ivory tower engineer
By Caroline Moseley
There is no such thing as an ivory tower engineer," declares Zellman Warhaft, visiting professor in Mechanical and Aerospace Engineering. "Every engineering device, whether a quaint windmill or a guided missile, has social implications."
Zellman Warhaft with spark ignition internal combustion engine (photo: Denise Applewhite)
It is ironic, he observes, that "engineering schools are so often located on the periphery of their campuses, because engineering exists entirely in a social context." Describing himself as "not a lone voice, but a minority voice," Warhaft sees engineering as "the most socially involved of the sciences." He would like engineering to attract students who are socially and environmentally concerned: "We should be recruiting, and educating, students with a broad view of the world," he says.
Engine and Atmosphere
Warhaft is teaching two courses at Princeton this year as 250th Anniversary Visiting Professor for Distin- guished Teaching. Last semester he taught a course for freshmen and sophomores, The Engine and the Atmosphere: An Introduction to Thermal Fluid Engineering. This semester he is leading a graduate seminar called Social Issues in Engineering Education: Components and Systems -- Engineering in a Social Context.
Warhaft designed The Engine and the Atmosphere as a broad introduction to engineering, he says. "Engineering is often taught in a piecemeal approach. Students learn various aspects of engineering, but they aren't integrated. A fragmented approach makes it difficult for the student to see the unity of the subject, let alone its connection to society."
Hence, Warhaft's course introduces thermal fluid engineering "as the interrelation among the various disciplines of thermodynamics, fluid mechanics, heat transfer and combustion." He also emphasizes the relation of technology to social and environmental effects, with the automobile as an example. "The engineering tendency is to talk about aerodynamics and drag reduction with the focus on the unit (the car) itself, rather than the effect of thousands of such cars on the local or even global atmosphere."
Yet, he points out, "Engineering students are ideally trained to learn about the greenhouse effect, with all their groundwork in thermodynamics and heat transfer." Warhaft aims "to show students that the atmosphere -- the sink into which the 'engine' is exhausting -- is not infinite. The atmosphere at this time in history is part of the engine, and therefore part of the engineer's domain."
Active voice in society
This semester's graduate seminar concentrates on a series of case studies, Warhaft says, examining ballistic missile systems "such as the Scud-Patriot encounters of the Gulf War." It's a technical course, "in which students do the relevant calculations, and read technology assessment reports, conference papers and records of congressional hearings."
Studying missiles is important, Warhaft says, because "many engineering students, particularly in mechanical and aerospace engineering, still go into defense or defense-related industries. Yet military activities are rarely discussed in the classroom."
He believes, "It is the responsibility of an engineer to ask, 'Why are we doing this particular job, and where is it going?'" He is not teaching ethics or morality, he insists, "just questioning the technical issues." The engineer "should be an active voice in society, because those with specialized knowledge have a special responsibility."
Fluid dynamics
Warhaft, a professor at Cornell University's Sibley School of Mechanical and Aerospace Engineering and a member of the Cornell faculty since 1977, received his BE in 1967 from the University of Melbourne and his 1975 PhD from the University of London. His textbook, An Introduction to Thermal-Fluid Engineering: The Engine and the Atmosphere (Cambridge Uni-versity Press, 1997), grew out of his teaching at Cornell.
His own professional interest is fluid dynamics, especially turbulence, which "transports heat and moisture." For example, he says, "If you pour cream in your coffee, the cream will remain pretty much at the top -- a demonstration of laminar, or layered, flow. But give it a few flicks with a spoon, and the coffee and cream mix -- that's turbulent flow."
Turbulence has its environmental pros and cons, he points out. "Turbulence causes higher drag over surfaces, so cars and planes need more fuel, and there's resistance to flow in pipelines." However, turbulence can also dispel smog. "If the ground is hot, the air convects up like a bubbling kettle," he explains. "But if the ground is cool and the air is warm, nothing wants to move. The cool air doesn't rise, and the warm air is happy where it is. This is called a temperature inversion -- there's no turbulence, and all the pollution stays in the air."
Orange glow through smog
Such is the current situation, especially in winter, in areas of the globe afflicted with industrial pollution. Warhaft recently returned from India, where he spoke at the Indian Institute of Technology in New Delhi, and Katmandu, Nepal, where he spoke at Tribhuran University on "Energy, Transportation and the Pollution of Our Cities." He describes Delhi at noon as "a vision of hell. The sun is only dimly visible as an orange glow through the smog." The cause of the Indian and Nepali smogs, as well as that in Mexico City and many other cities, he says, is vehicular and industrial pollution.
"The pollution will ultimately affect us all," he says. "It is selfish to think that we are okay while the rest of the world is a mess. We use other countries to produce our products -- China is just as polluted as India -- so surely we must share the responsibility."
At Princeton, in addition to teaching and offering departmental seminars, Warhaft will speak on "Engineering in a Social Context" on February 23, in an event cosponsored by the Department of Mechanical and Aerospace Engineering and the Center for Human Values.