SMOOTHING OUT THE BUMPS ON THE ROAD TO ENGINEERING

FAYETTEVILLE, Ark. - Learning engineering fundamentals can be a rough road, but University of Arkansas mechanical engineering faculty are trying to smooth out the bumps. Their award-winning paper details the results of their investigation.

"Engineering faculty understand that the differences in dynamics and thermodynamics are a matter of usage, not science," explained Larry Roe. "But those differences can be very confusing to students."

Roe and Rick Couvillon, associate professors of mechanical engineering, teach thermodynamics, while Ing-Chang Jong, professor of mechanical engineering, teaches dynamics and statics. After investigating the ways in which faculty present basic materials, the researchers prepared a concise description of these differences. Jong presented their paper, The Meandering Road from Dynamics to Thermodynamics and Vice Versa, last week at the American Society for Engineering Education annual meeting in Montreal, where it won a Best Paper Award.

Although dynamics and thermodynamics have similar sounding names, they have considerably different subject content, according to Jong. Some definitions and conventions in dynamics and thermodynamics are given differently and can be confusing to unsuspecting undergraduates.

Dynamics is a physical science that describes and predicts the conditions of bodies under the action of unbalanced forces, such as a sack of sand falling on a concrete floor. A fundamental course in mechanics, it is typically taught in mechanical engineering, but other engineering disciplines often require that their students take these courses. Thermodynamics, a physical science of energy, is required and taught in many engineering disciplines, including mechanical, chemical and petroleum engineering.

"Thermodynamics has a great deal to do with the transfer, storage and conversion of energy, but it has little to do with the dynamics of particles and rigid bodies from the mechanics point of view," said Jong.

Problems arise because both disciplines use the same terms - such as work and heat - but in different ways or to describe different phenomena. But the situation can get even worse. For example, in dynamics there are instances where the mechanical energy of an object is not conserved. However, the First Law of Thermodynamics asserts that energy can neither be created nor destroyed; energy can only change forms.

"A lot of the reason for this is historical," explained Roe. "Terms came into usage as a discipline developed. For mechanics, that was around 384 BC and for thermodynamics it was in the 1850s. It wasn’t until the 20^th century, when a common engineering curriculum was developed, that conflicting usage became obvious."

In many curricula, these differences are not addressed in detail, although they may be mentioned in passing. For example, mechanics courses do not include a discussion of heat, which is an integral part of thermodynamics. Since students do not take these courses in a specific order, the emphasis or neglect of certain topics can be particularly confusing.

"This is not an invisible difference," explained Roe. "It often leaves students confused."

The researchers do not advocate changing the terminology, however. "Every now and then someone will embark upon a crusade to change terms or symbols in a discipline, but it is rarely successful," said Roe.

Rather, they believe that increased awareness on the part of engineering faculty will produce more effective results. And Jong is currently incorporating these discussions into the next edition of his textbooks, Engineering Mechanics: Dynamics and Engineering Mechanics: Statics and Dynamics.

"Being aware of the differences in terminology and phraseology in different subjects, instructors can enhance their effectiveness in communicating with students, and students will

learn these subjects more effectively," Jong said.

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