Publications
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Freevalve: Control and Optimization of Fully Variable Valvetrain-enabled Combustion Strategies for High Performance Hybrid Vehicles
SAE Technical Papers
With ever stricter legislative requirements for CO2 and other exhaust emissions, significant effort by Original Equipment Manufacturers (OEMs) have launched a number of different technological strategies to meet these challenges such as Battery Electric Vehicles (BEVs). However, a multiple technology approach is needed to deliver a broad portfolio of products since battery costs and supply constraints are considerable concerns hindering mass uptake of BEVs. Therefore, further investment in IC engine technologies to meet these targets are being considered, such as lean burn gasoline technologies and other high efficiency concepts such as dedicated hybrid engines. Hence, it becomes of sound reason to further embrace diversity and develop complementary technologies to assist in rapid conclusions in the transition to the next generation hybrid powertrains. One such approach is to provide increased valvetrain flexibility to afford new degrees of freedom in engine operating strategies. Freevalve is an electronically controlled, pneumatic spring-based, valve actuation system enabling independent control of ICE valves conceptualized by Koenigsegg’s Freevalve AB. Developed primarily in line with increasingly strict emissions legislations, preliminary findings have demonstrated that the cam-less engine technology withholds significant potential, offering up to 10% decreased fuel consumption and 60% less cold start emissions on an average drive cycle. This paper aims to demonstrate the most recent valve operating strategies enabled by the cam-less engine technology using a simplified 3-cylinder hybrid 1D engine model in GT-Suite.
Freevalve: Control and Optimization of Fully Variable Valvetrain-enabled Combustion Strategies for Steady-state Part Load Performance and Transient Rise Times
SAE World Congress 2023: Combustion Control and Optimization
As part of research completed in his first year of PhD, the published work addresses industrial concerns relating the use of fully variable valvetrain (FVVT) technologies in ICEs for part load and transient performance. Adopting a data-based approach, together with his industry and academic partners Koenigsegg, Freevalve, and KAUST, Abdu concluded optimal FVVT-enabled valve strategies targeting maximum scavenging and optimized EGR rates for maximum fuel conversion efficiency and minimal brake specific fuel consumption. The study then goes on to explore the benefits of integrated FVVT technologies in turbocharged vehicles for transient rise times and how the technology assists in minimization of turbo lag and improvement of drivability. Abdu has been invited to present the published work at WCX SAE World Congress Experience, taking place in Detroit, MI, USA in April of 2023.
Freevalve: A Comparative GWP Life Cycle Assessment of E-fuel Fully Variable Valvetrain-equipped Hybrid Electric Vehicles and Battery Electric Vehicles
SAE World Congress 2023: Lifecycle Assessment
In collaboration with our second cohort AAPS CDT student, Joris Simaitis, Abdu authored a Lifecycle Assessment (LCA) paper that has recently been published by SAE International for WCX SAE World Congress Experience 2023 taking place in Detroit, MI, USA. The work presents a comparative global warming potential (GWP) LCA case between a DAC efuel FVVT-equipped hybrid electric vehicle (HEV) and a battery electric vehicle (BEV) for a lifecycle of 150,000 km on two different grid options (a) global average mix and (b) renewable mix. The study uses standardized and peer reviewed LCA database, Ecoinvent, and professional open-source sustainability and LCA footprint modelling software OpenLCA. They found that a net reduction of up to 55% in favour of the DAC efuel FVVT-equipped HEV is evident. The comparison is a first of its kind in the published literature domain, setting a benchmark for DAC efuel FVVT-equipped HEVs in future comparative LCA investigations. Both students have been invited to attend the conference and are due to present the published work.