Home Experiments in Mechanical Engineering

Latif M. Jiji, Feridun Delale and Benjamin Liaw

The City College of The City University of New York

<back to content> Introduction <next chapter>

This publication describes 14 experiments in mechanical engineering which students can perform at home using readily available supplies. The experiments are designed for integration with lecture courses in thermodynamics, fluid mechanics, heat transfer and solid mechanics. They represent applications of theoretical concepts taught in mechanical engineering courses. In each experiment theoretical predictions are compared with experimentally obtained results. Although crude measuring techniques are used at home, comparison between theoretical and experimental results is usually satisfactory.

Many theoretical undergraduate engineering courses involves concepts, conditions, processes and approximations that are not familiar to students but can be elucidated and clarified through experiments. Although one of the functions of laboratory experiments is to complement lecture courses, it is often difficult to fully exploit them as learning instruments. The ever increasing sophistication and complexity of instrumentation and data acquisition tend to obscure the phenomenon under study, making it difficult for students to exercise their intuition and experience and thus fully benefit from laboratory experiments. Furthermore, unfamiliarity with operating conditions, calibration procedures, uncertainty about the role of theory, and above all, the painful process of report writing, combine to inhibit enthusiasm about laboratory courses. Thus both the opportunity to use experiments to illustrate and reinforce theory, and to rely on theory to explain and motivate experiment are lost.

A new approach is developed in which very simple experiments which students perform at home using common materials and supplies are integrated with lecture courses and used as a learning device. The use of home experiments was inspired by our experience in teaching our undergraduate lecture course in heat transfer. It was found that when the instructor performs a crude experiment in class to illustrate an application of a theoretical topic, such as transient conduction or fin analysis, students exhibit unusual interest and enthusiasm. Suddenly theoretical ideas take on new meaning and significance. Encouraged by students' responses, the practice was institutionalized in a modified form. Students were asked to perform the experiments at home using household supplies and tools such as a wire hanger, scale, ruler, watch, boiling water, etc. Although they were surprised and amused by such an unorthodox approach to the study of theoretical topics, they reacted even more positively to this arrangement. Performing the experiment motivated students to look more carefully at the theory and examine the assumptions involved.

The concept of performing simple experiments at home is of course not limited to heat transfer. It can be applied to many engineering courses. Recognizing its general nature and utility we have extended its application to courses in thermodynamics, fluid mechanics and solid mechanics through an NSF grant. The project was formalized by organizing the material for each experiment into modules which can be used by other schools. An important component of each module is a presentation of a laboratory version of the experiment with the corresponding results. A sample module is given in Section IV.

<back to content>Concept Description <next chapter>

The simple experiment concept is distinguished by several important features. First, it addresses a broad segment of the undergraduate engineering curriculum affecting lecture courses in several disciplines. Second, it can be easily integrated with existing lecture courses and does not require curriculum changes. Third, it makes minimal demands on the instructor's time. Fourth, it increases students' involvement and thereby increases their motivation to learn. Fifth, it trains students in the processes of simplification, approximation and modeling. Sixth, it creates an environment which inspires innovation and improvisation.

Each experiment is skillfully designed to engage and involve students, capture their attention and motivate them to raise questions and seek answers. Experiments are carefully selected to meet the following critical requirements:

back to contentDescription of Home Experiments next chapter

The following are descriptions of 14 experiments in Thermodynamics, fluid mechanics, heat transfer and solid mechanics. Included are typical results and comparisons between experimental measurements and theoretical predictions.

Thermodynamics next topic