The objective of this project is to design and build a device that is able to defrost a car windshield more effectively than current methods while producing a low environmental impact. Current methods, which include removing the ice using plastic scrapers or melting the ice by running a car on idle to heat up the windshield, prove to be ineffective or environmentally damaging. This device must be able to melt up to one sixtenth of ice from a distance of twenty feet, while meeting the environmental design parameters detailed in the report. An infrared heating element will be used with a reflective shield to create a focused beam of energy that will be used to defrost the windshield. A series of heat transfer calculations determined the theoretical energy required to melt a sixty-four foot area of ice to be 76 watts, and the amount of energy actually transferred through the focused beam after losses was determined experimentally. The testing of a scale model, which utilized diffuse visible light, showed there was an intensity gain of 3 percent from 19 foot by adding a reflector. A focusing factor of about 3 percent was found by a comparison of the intensity of the element at close range to the use of a reflector at 19 feet. The results show that about 9 kW would be needed to defrost one sixtenth of ice to meet the design criteria. The heat transfer calculations, which were completed for an initial set of variables, were used as a tool to see how the system reacted in terms of time and power as other variables were changed. A set of heat transfer calculations were done on the proposed prototype model in order to perform material selection, and it was found that 6061-Aluminum would be acceptable. The final construction of the prototype, using a single 540 W heating element, resulted in testing to find how well the design performed. As the scale model indicated, the time would be too great to melt the frost. Future prototypes will use more powerful elements to match the calculations discussed in this report, and melt the designated amount of frost in a reasonable tin frame.
automobile maintenance, car windshield defroster
Department of Mechanical, Industrial, and Manufacturing Engineering
Brown, Todd; Grace, Christopher; Lynch, Scott; McIntosh, Scotlund; and Melanson, Katie, "Infrared Windshield Defroster" (2008). Capstone Design Program: Mechanical Engineering. Paper 67. http://hdl.handle.net/2047/d10012953
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