Experimental Investigation on Open Waste-Gate Behaviour of Automotive Turbochargers

Turbocharging is becoming a key technology for automotive engines as a support to the downsizing concept to get reduced CO₂ emissions.

Usually, a waste gate (WG) valve is installed as a turbocharger regulating system in spark ignition (SI) applications; however, further research work is required to improve engine-turbocharger matching when the by-pass port is open.

An experimental investigation was developed at the University of Genoa (Italy) on a small waste-gated turbocharger in order to get a better understanding of WG behaviour and of its interactions with the turbine rotor flow.

In the paper the main results are presented focusing on impeller and by-pass mass flow contributions and on turbine volute pressure distribution.