A Proposed Vehicle For Delivering A Mechanical Engineering Systems Laboratory Experience

The practice of mechanical engineering requires the ability to investigate and analyze complex thermal and mechanical systems. An effective way for the students to develop their understanding of mechanical engineering systems is for them to get hands-on experience by working in small groups in a laboratory environment. This paper describes a plan to develop a unique capstone laboratory course that provides this experience. The course, Engin ering Systems Laboratory will be based upon an integrated sequence of laboratory experiments on an automobile and its subsystems. The automobile is chosen as the system to study because it is compact, relatively inexpensive and in the direct realm of experience of most students. More importantly, its many complex subsystems provide opportunities for the students to apply the spectrum of their mechanical engineering knowledge, including the principles of mechanics, dynamics, thermodynamics, heat transfer, and controls. INTRODUCTION An integral part of the undergraduate mechanical engineering curricula at the University of South Carolina is sequence of four mechanical engineering laboratory courses: Measurements and Instrumentation, Engineering Materials, Fundamentals of Microprocessors, and Senior Laboratory. Senior Lab is a two-credit hour course consisting of one hour of lecture and three hours of lab each week. Laboratories are offered to sections of about eight students. Currently, it is a good class, but not a great class. The existing experiments were selected primarily to support upper-level mechanical engineering courses, and include Psychrometric Study Of Cond itioned Air, Air Conditioner COP As Function Of Condenser Temperature, Transient Heat Conduction, Heat Transfer To Circular Cylinder In Cross Flow, Hydraulic And Energy Grade Line, Internal Combustion Engine Performance, Parallel And Counterflow Heat Exchanger Performance, Wind Tunnel Experimentation NACA 4418 Airfoil Section, Vibration Of A Cantilever Beam, Fracture Mechanics Experiment, and the Hydraulic Trainer. The major drawback of the existing laboratory experience is that the experiments themselves are not directly related to one another. Further, the existing lab equipment is suitable for students to gain insight into various engineering principles, but most items support one experiment only. The result is a large number of relatively expensive items which must be maintained, that occupy laboratory space, yet are used only once a semester. Because the students go from one unrelated experiment to another throughout the semester, they do not have the opportunity to develop the “system level” perspective necessary to analyze and understand complex thermal and mechanical systems. Further, with the current equipment, the experiments are “set-up” for the students and do not require any design of the experiment, or much in the way of instrumentation installation. P ge 340.1 Trends in Mechanical Engineering 2266 2 The USC Mechanical Engineering faculty decided that a more unified experience is appropriate for the senior laboratory course. It is believed that practicing mechanical engineers need a systems perspective, which can be fully developed only when systems lab experiences are also involved. To reflect this emphasis, the course will be renamed the Engineering Systems Laboratory. In it, students approach and analyze engineering problems from a systems viewpoint, design experiments, apply computer-based instrumentation to study system performance, document their results in writing, and make oral technical presentations. THE SYSTEM UNDER INVESTIGATION It is not desirable or even possible to attempt to expose students to every type of system that they might work with throughout their professional career. In designing the systems lab, one must select a number of systems for the students to investigate in detail. The selected systems must provide opportunities for the students to apply the spectrum of their mechanical engineering knowledge, including the principles of mechanics, dynamics, thermodynamics, and heat transfer. The automobile is the ideal system for this laboratory for several reasons: • It is compact, yet it incorporates such a variety of subsystems that it involves almost all of the fundamental principles of mechanical engineering; • For all its complexity, it is a relatively inexpensive system for study; and • It is in the realm of experience of all students, so they can easily relate to system performance criteria such as efficiency, handling and other factors affecting vehicle operation. These features make the automobile a powerful learning vehicle. This laboratory course will be implemented at the University of South Carolina using the Legends car similar to the one shown in Figure 1. The National Collegiate Association for Racing (NCAR), an academic motorsport involving engineering colleges throughout the country, currently races these 5/8-scale replica vehicles. There are primarily two reasons to use the Legends car: Figure 1. Legends car raced by USC NCAR Engineering Team • There is tremendous enthusiasm among our students for the NCAR sport. Those surveyed are excited about applying their engineering knowledge and experimenting with a car similar to the one raced in competition. Such enthusiasm can be a tremendous asset to any required course, particularly a laboratory course; and • The relationship between the Engineering Systems Lab course and the NCAR racing team is synergistic. Corporate sponsorship of the NCAR team provides funds that supplement the College's resources for updating the lab equipment, and the course provides an opportunity for all mechanical engineering students to benefit educationally from the NCAR program.