Experimental investigation on the transient response of an automotive turbocharger coupled to an electrically assisted compressor

An experimental investigation on a turbocharger coupled to an electrically assisted boosting system was developed at the turbocharger test rig of the University of Genoa. In the paper, a description of the experimental set-up and the measuring equipment adopted to test the e-booster coupled to the main turbocharger is reported. The e-booster system (eSC) was maintained in an upstream configuration and the main instantaneous parameters (pressure, mass flow rate and turbocharger rotational speed) were measured using high frequency response transducers. This layout allowed to analyse the transient response of the main turbocharger and to highlight the gain in the turbo lag when the eSC is working. A specific experimental technique was made up in order to provide experimental information on the time requested by the turbocharger to reach a compressor outlet pressure value with and without the presence of the eSC. The target was to properly control each variable (throttle valve, waste-gate valve and the by-pass valve of the eSC) to perform reproducible and repeatable test with and without the adoption of the electrically assisted compressor. The work presented in this paper was conducted with support from The H2020 UPGRADE (High efficient Particulate free Gasoline Engines) Project (Grant Agreement Number: 724036).