Improved Army Exhaust Brake
presentationposted on 12.09.2014, 00:00 by Eric Jensen, Jeff Watters, Kate McKinnon, Mark Shimelpfenig
The Army Materiel Systems Analysis Activity has commissioned a team of four students from the University of Wyoming to develop an improved exhaust brake for the US Army. The current exhaust brake is a butterfly valve located in the exhaust stream which when closed provides back pressure and a braking effect on the engine. When descending steep grades this provides vehicle operators with more control and extends the life of traditional friction brakes. The current exhaust brake is corroding and seizing at a rate of approximately four times per engine life of 1,000,000 miles. This creates much waste and unnecessary difficulty and danger for United States military personnel. To improve the brake, key components of the butterfly valve have been replaced with corrosion resistant stainless steel parts and stainless steel bushings have been shrink-fit into the housing. The stainless steels selected were chosen to minimize the probability of galling, the magnitude of thermal stresses, and galvanic corrosion. To ensure proper operation and modeling of the improved brake, ambient temperature, thermal shock, corrosion, cyclic operation, and mechanical loading tests were performed. With these alterations the exhaust brake is designed to last the life of the engine with minimal maintenance.