Investigation of a GDI injector with an innovative flowmeter for high-pressure transient flows

A new flowmeter for high pressure flows, characterized by intense dynamic events, is presented. The flowmeter algorithm is based on the measurement of two pressure signals along the investigated pipe, and the flowrate is obtained through an ordinary differential equation given by the combination of the continuity and the momentum partial differential equations. This flowmeter has been applied to a GDI injector to monitor the flowrate that enters the injector during an injection event. A 1D numerical model of the GDI injector has been set up and validated, and the numerical outcomes have been used to confirm the consistency of the experimental results obtained from the new flowmeter, for both single and pilot-main injections. The internal dynamics of the injector has also been investigated, using both the 1D numerical tool and the innovative flowmeter. A possible feedback-control strategy has been set up to compensate for any inaccuracy of the injected mass by applying the flowmeter to the hydraulic high-pressure circuit.