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Hydrogen is an energy vector with low environmental impact and will play a significant role in the future of transportation. Converting a spark ignition (SI) engine powered vehicle to H2 fueling has several challenges, but was overall found to be feasible with contained cost. Fuel delivery directly to the cylinder features numerous advantages and can successfully mitigate backfire, a major issue for H2 SI engines. Within this context, the present work investigated the specific fuel system requirements in port- (PFI) and direct-injection (DI) configurations. A 0D/1D model was used to simulate engine operating characteristics in several working conditions. As expected, the model predicted significant improvement of volumetric efficiency for DI compared to the PFI configuration. Boosting requirements were predicted to be at levels quite close to those for gasoline fueling.

Syngas produced from biomass gasification is being increasingly considered as a promising alternative to traditional fuels in Spark-Ignition (SI) Internal Combustion Engines (ICEs). Due to the low energy density and extreme variability in the composition of this gaseous fuel, numerical modeling can give an important contribution to assure stable engine performances. The present work intends to give a contribution in this sense in this sense, by proposing a multi-level set of approaches, characterized by an increasing detail, as a tool aimed at the optimization of energy conversion of non-conventional fuels. At first, a specific characterization of the dependency of the syngas laminar flame speed upon its composition is achieved through an iterative approach pursued in the ANSYS ChemkinTM environment, where validated correlations of the flame speed tuning parameters are obtained in a zero-dimensional framework.

Water removal from Proton Exchange Membrane (PEM) Fuel Cell (FC) mainly involves two phenomena: some of the emerging droplets will roll on the Gas Diffusion Layer (GDL), others may impact channel walls and start sliding along the airflow direction. This different behaviour is linked to the hydrophobic/hydrophilic nature of the surface the water is moving on. In this paper, the walls of the channel of a FC were characterized by applying optical techniques. The deposition of droplets on the channel wall led to an evaluation of the proper range for Contact Angle Hysteresis (CAH = 55° - 45°), and due to the high wettability of the surface, droplets dimension was defined with a dimensionless parameter B/H. Under high crossflow condition (15 m/s) a sliding behaviour was observed. The channel features determined through image processing were used as boundary conditions for a 2D CFD two phase simulation employing the Volume of Fluid (VOF) model to keep track of the fluids interface.