A Rapid Prototyping Application In Wind Tunnel Testing A Student Project

3D printing is a rapid prototyping process which creates a part layer by layer by spraying a binder into a bed of powder. This process is used in industry to produce concept models for marketing, fit, form and function models, as well as patterns for molds. A team of Mechanical Engineering Technology students at Penn State Erie, working on a senior project to test the down force on a late model dirt stock car, has integrated the use of rapid prototyping into their project in an innovative way. The project called for the students to build a model of the car, and to conduct wind tunnel tests to determine the down force that is generated. This student team decided to use the 3D printed prototype directly in a wind tunnel, since it appeared to be a quick, relatively inexpensive method for providing test results. Several problems arose during the design and manufacture of the model. One of the main concerns was the strength of the part, since the model contains several thin sections which would have to both survive the build process and withstand the force of the wind. Other issues included the amount of detail needed in the model, model size, and design of the model to allow for simple, economic changes. This paper reports on these issues, and how they were resolved.