Controlling Engine Air Balance through Manifold Design
This paper presents results from an investigation into the causes and correction of inlet air imbalance to power cylinders of a two-stroke integral compressor engine. The project is funded by the Department of Energys (DOE) Office of Fossil Energy and managed by the National Energy Technology Laboratory (NETL) as part of their Natural Gas Infrastructure Reliability Program. Co-funding for this project is provided by GMRC, El Paso, Cooper Compression, and Optimum Power Technology. A laboratory GMVH-6 turbocharged engine was utilized to provide baseline data. In addition to many performance and dynamic measurements, the engine was disassembled to quantify the geometric variations among cylinders. Three of the six power cylinders were also flow tested to investigate the variance in port discharge coefficient. From the dimensional and performance measurements, a computational model of the engine was created. The computational model was utilized to further distinguish the effects of dimensional variation and to aid in the design of manifolds or manifold modifications to achieve air balance. Prototype components are to be manufactured and validation testing on the laboratory engine is planned. After which, a cost-benefit analysis is to be performed from the results. The desire for improved air balance relates to the potential for improvements to engine efficiency, emissions, detonation and misfire tolerance, and mechanical integrity.