Active Control Turbocharger (ACT), a method to improve energy extraction from an engine exhaust gas

Variable geometry turbochargers (VGT) offer boosting solution which overcomes many of the conventional turbo charging problems such as turbolag and engine matching. However, VGT which are dominantly controlled based on engine load and speed, does not completely address the pulsating nature of the exhaust gas. Thus, the current VGT are not fully utilizing the energy available especially at the lower region of the exhaust pulse. An advanced turbo charging technique called Active Control Turbocharger (ACT) is proposed and demonstrated through experiment and simulation; where the turbine geometry will be operated actively to adapt to the pulsating exhaust flow in order to maximize the energy extraction while minimizing the penalty on the overall turbine efficiency.© 2009 ASME