Mechanical Engineering Department
BS in Mechanical Engineering
Sarah T. Harding
Bull Outdoor Products, Incorporated, a barbeque grill and outdoor kitchen manufacturer, sponsored this project with the intent of improving the temperature uniformity across the surface of their barbecue grills. For this project, the Cal Poly team of mechanical engineering students, Monty Dodge Jr. and Samuel Melo, used the Brahma grill head model with setups for both natural gas and propane. In order to determine exactly what the uniformity across the grill surface was, the student team designed a testing apparatus which would measure a grid of temperature locations one inch apart spanning an area 16 by 36 inches. Developing a testing method which produced accurate results was done over five separate tests, at which point the team began testing various geometrical configurations of flame guards (flame tamers) to determine how these geometries affected the overall temperature uniformity. Across all of the tests, the results clearly showed that temperature in the back of the grill was consistently higher than the front. It was also found that approximately half of the propane grill, on the left side, was significantly lower temperature than the right. Upon further investigation, and bench testing a propane manifold for pressure at each valve, it was determined the cause of the discrepancy in temperature from left to right was the result of a pressure drop in the manifold. Recommendations were then made to Bull Outdoor Products with regard to how this might be improved. The student team did, in the end, design a set of louvers which would direct heat flow from the back to the front of grill. These new louvers did improve the temperature distribution from front to back, however, the most valuable deliverable was the actual design of the test apparatus, the test method, and method of data analysis used.