Wide-Range High-Boost Turbocharging System Using Advanced Aerodynamic Design Features

Increasingly stringent exhaust emissions and fuel economy legislation is forcing automotive engine designers to: 1) demand increased pressure ratios from turbocharger compressors to ensure complete fuel combustion, 2) use Exhaust Gas Recirculation for emission reduction, and 3) reduce engine displacement while maintaining or even increasing output power to reduce fuel consumption. These three changes have led to the need for significantly improved turbocharger operability. Specifically, the compressor must operate over a wider flow range, while achieving both high pressure ratios and high efficiency for high and low flows. While a variety of range extension devices have been developed, a novel compressor configuration is proposed which allows a single compressor to mimic the behavior of a small and a large compressor with minimum complexity. Based on the prior development work performed, we anticipate the compressor technology to have the following benefits compared to current commercially available turbochargers: 1) 3% improvement in fuel economy compared to a commercial turbocharger, and 2) significantly larger range, allowing low-flow low-pressure ratio conditions to be achieved that would not be possible with a current commercial turbocharger. In the Phase II project, several candidate configurations will be designed and fabricated, allowing for detailed component testing to be performed. Based on those tests, a preferred configuration will be selected and tested with an engine relevant to automotive gasoline applications to determine overall engine performance enhancements of the novel technology. Commercial Applications and Other Benefits: Upon successful completion of Phase II, automotive and truck turbocharger designers and manufacturers can be supplied with intellectual property licensing and associated tools to help them design and/or produce high performance turbochargers that will operate over a wider range of operating conditions compared to current commercial turbocharger systems, increasing fuel economy and reducing emissions without a significant increase in cost, weight or size.