The electrification of powertrains provides a critical opportunity to change the way that engines are designed and developed, allowing their efficiency to be increased and their cost reduced.

This paper draws on ongoing Ricardo projects in the field of dedicated hybrid engines (DHEs). The Magma xEV combustion concept employs very high compression ratio, long stroke architecture, and advanced ignition and knock mitigation technologies, for DHEs requiring the highest efficiency. In the latest research project a pre-chamber combustion system (with both active and passive operation) has been applied to the Magma xEV engine, in order to enable the highest levels of charge dilution and further increase brake thermal efficiency. The research focussed on benefits of pre-chamber ignition as compared to conventional spark ignition and corona discharge ignition. The comparison of charge dilution using excess air (lean operation) and exhaust gas recirculation are presented. A route to brake thermal efficiency beyond 45% is discussed.

The combustion concept has been developed using virtual product development approaches and validated with a single-cylinder research engine.

SAE 2022-01-0422
Presented at the WCX SAE World Congress 2022.