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Commercial vehicle powertrain is called to respect a challenging roadmap for CO2 emissions reduction, quite complex to achieve just improving technologies currently on the market. In this perspective alternative solutions are gaining interest, and the use of green H2 as fuel for ICE is considered a high potential solution with fast and easy adoption. NOx emission is still a problem for H2 ICE and can be managed operating the engine with lean air fuel ratio all over the engine map. This combustion strategy will challenge the boosting system as lean H2 combustion will require quite higher air flow compared to diesel for the same power density in steady state. Similar problem will show up in transient response particularly when acceleration starts from low load and the exhaust gases enthalpy is very poor and insufficient to spin the turbine. The analysis presented in this paper will show and quantify the positive impact that a supercharger has on both the above mentions problems.

Commercial vehicles are moving in the direction of improving brake thermal efficiency while also meeting future diesel emission requirements. This study is focused on improving efficiency by replacing the variable geometry turbine (VGT) turbocharger with a high-efficiency fixed geometry turbocharger. Engine-out (EO) NOX emissions are maintained by providing the required amount of exhaust gas recirculation (EGR) using a 48 V motor driven EGR pump downstream of the EGR cooler. This engine is also equipped with cylinder deactivation (CDA) hardware such that the engine can be optimized at low load operation using the combination of the high-efficiency turbocharger, EGR pump and CDA. The exhaust aftertreatment system has been shown to meet 2027 emissions using the baseline engine hardware as it includes a close coupled light-off SCR followed by a downstream SCR system.

Emission, fuel economy and productivity in non-road mobile machinery (NRMM) depend largely on drive cycles. Understanding drive cycles can provide the in-depth information and knowledge that help the system integrator better optimize the vehicle management system. Some non-road engine test cycles already exist nowadays. However, these cycles are mainly for engine emission regulation purpose, and not closely tied to real world applications. Therefore, from both industries and academia, it has been the common practice to instrument and retrofit a vehicle, assign a professional driver operate the retrofitted vehicle for real testing, and compare the results to the baseline vehicle under the similar operating conditions. Obviously this approach is time consuming and resource intensive. In this paper, we attempt to address this issue by introducing a method of constructing standard drive cycles from in-field operation data.

Cylinder deactivation (CDA) is an effective method to adjust the engine displacement for maximum output and improve fuel economy by adjusting the number of active cylinders in combustion engines. A Switching Roller Finger Follower (SRFF) is an economic solution for CDA that minimizes changes and preserves the overall width, height, or length of Dual Overhead Cam (DOHC) engines. The CDA SRFF provides the flexibility of either transferring or suppressing the camshaft movement to the valves influencing the engine performance and fuel economy by reducing the pumping losses. This paper addresses the performance and durability of the CDA SRFF system to meet the reliability for gasoline passenger car engines. Extensive tests were conducted to demonstrate the dynamic stability at high engine speeds and the system capacity of switching between high and low engine displacement within one camshaft revolution.

New regulations, rising fuel costs and environmental concerns are driving significant improvement in heavy duty truck aerodynamics and rolling resistance that fundamentally change the power needs of heavy duty trucks. Furthermore, exhaust energy recovery technology is evolving and driving a change in the power management strategies. Together with advances in hybrid technology, these changes open the potential for a cost-effective line haul hybrid line of trucks. This paper will present a simulation study that was performed in order to evaluate the potential fuel economy benefits of a heavy duty powertrain for commercial vehicles. The architecture includes hybrid electric components paired with a waste heat recovery system. The electric energy can be used to reduce engine load during peak power requests. The sources for the electric energy are both braking energy regeneration as well as conversion of waste heat to electricity via a high speed generator.