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The hydrogen engine is one of the promising technologies that enables carbon-neutral mobility, especially in heavy-duty on- or off-road applications. In this paper, a methodological procedure for the design of the combustion system of a hydrogen-fueled, direct injection spark ignited commercial vehicle engine is described. In a preliminary step, the ability of the commercial 3D computational fluid dynamics (CFD) code AVL FIRE classic to reproduce the characteristics of the gas jet, introduced into a quiescent environment by a dedicated H2 injector, is established. This is based on two parts: Temporal and numerical discretization sensitivity analyses ensure that the spatial and temporal resolution of the simulations is adequate, and comparisons to a comprehensive set of experiments demonstrate the accuracy of the simulations. The measurements used for this purpose rely on the well-known schlieren technique and use helium as a safe substitute for H2.

The strategies adopted to control the combustion in Diesel applications play a key role when dealing with current and future requirements of automotive market for Diesel powertrain systems. The traditional “open loop” control approach aims to achieve a desired combustion behaviour by indirect manipulation of the system boundary conditions (e.g. fresh air mass, fuel injection). On the contrary, the direct measurement of the combustion process, e.g. by means of in-cylinder pressure sensor, offers the possibility to achieve the same target “quasi” automatically all over the vehicle lifetime in widely different operating conditions. Beside the traditional combustion control in closed loop (i.e. based on inner torque and/or combustion timing), the exploitation of in-cylinder pressure signal offers a variety of possible further applications, e.g. smart detection of Diesel fuel quality variation, control of combustion noise, modeling engine exhaust emission (e.g. NOx).

The world of diesel is becoming more technically complex due to the increasingly restrictive legislation regarding emissions, fuel consumption, and real driving emissions evaluations (RDE). Simulation provides a mechanism for the investigation and optimization of diesel engine performance, new engine concepts, RDE, and after-treatment design. This can contribute to solve the problems that the restrictive legislation creates. In addition to these generally valid capabilities of simulations, our model development is focused on the mission to use correctly sized models to reduce the usage of resources and make simulation an even more rapid and cost effective method. In this contribution, we present our approach for simulation as an advanced integrated tool capable of answering challenging questions presented by emission and fuel consumption reduction in future legislation frameworks.

The aim of this work is the development of an energy-based model to predict primary break-up of urea and water (Ad Blue) sprays in condition typical of Selective Catalyst Reduction (SCR) systems. The atomization model for Ad Blue injection, developed in the present investigation, performs an energy balance of the liquid column to asses its deformation near the nozzle exit and to predict the dimension of droplets after the primary break-up. To formulate the energy balance it is necessary to evaluate several terms: the theoretical kinetic energy of the jet in absence of dissipation, its real kinetic energy, the fraction of energy dissipated due to turbulence effects, the surface energy before break-up, the surface energy of the droplets after the break-up. The model was implemented in the KIVA3v code and experimental data from Malvern analysis were used for the validation.