Improvement of Engine Transient Performance by Compressor Scroll of Turbocharger with Circumferential Non-Linear Sectional Area Distribution

In order to prevent global warming, improving automotive fuel economy has become one of the biggest challenges. Therefore, a lot of attention has been drawn to turbocharging technology. However,“turbo lag”which is a common phenomenon in conventional turbocharger could worsen the vehicle's drivability. To cope with such drawback, a new-concept compressor cover which has non-linear area distribution has been designed with CFD analysis. And, it is experimentally evaluated, and the result shows that the efficiency of new compressor cover at low flow condition increases by 1％. The result of on-engine performance test also shows that this new compressor cover can improve transient response by more than 60％ for low-to-medium engine speed conditions.