Centrifugal Pump Design, Fabrication And Characterization: A Project Driven Freshman Experience

Abstract

Abstract NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Centrifugal Pump Design, Fabrication and Characterization: A Project-Driven Freshman Experience Abstract Students beginning the first year of an engineering program generally have limited experience with the tools engineers can harness to solve problems. Teaching students how to use problem solving tools at the point when they fully appreciate the nature of a problem is a powerful method of instruction. Real problems do not present themselves in response to the existence of a tool; rather, tools are developed to assist in solving existing problems. A project centered around a centrifugal pump has been developed that is effective in impressing upon freshmen the need for learning analytical tools commonly used in engineering. Approximately 350 first term freshmen work in groups of two to design and fabricate centrifugal pumps that they then characterize. The project is quite sustainable, as the cost of materials per pump is only a few dollars. The freshman students participate on an individual basis in a broad range of activities that enhance their appreciation of the importance of engineering tools and analysis. Students design their pump using solid modeling software, giving them experience with part modeling and assemblies. The designs are also fabricated by the students using milling machines and rapid prototyping. The parts are assembled, yielding a working pump. Each student develops a pump curve by measuring flowrate versus head and applying plotting and regression techniques in a spreadsheet. Students also measure voltage and current supplied to the pump motor to characterize pump efficiency. This gives them a practical feel for conservation of energy and deeper understanding of electrical power. This paper describes our experiences with implementing this project in a college-wide freshman curriculum and includes student survey data regarding the effectiveness of the project. This project is a part of a larger program designed to impart rich, hands-on experiences to students to solidify their understanding and retention of engineering concepts. The program is being developed with funding from the National Science Foundation. The centrifugal pumps described here are used in a project in a subsequent course in which students develop a salinity- and temperature-controlled fish tank. Introduction There is a proverb that is attributed alternately to the Chinese and to Native Americans that says “Tell me and I’ll forget; show me and I may remember; involve me and I’ll understand.” Educators in engineering who are forward-thinking have realized for a long time that when passive, lecture-based instruction is replaced with hands-on, project-based learning, the result is the development of students who are confident in their ability to accomplish real achievements with their learning1. The move toward project-based freshman curricula began in the United States in the 1990s; with key motivation arising from the National Science Foundation

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