Development of a 1D Model of an Evaporative Emission Control System

This master course thesis has been developed at POWERTECH Engineering S.r.l., an engineering consulting company specialized in the field of 1D and 3D CFD analysis which cooperates with several suppliers and OEMs in the automotive field. The thesis work has been made in collaboration with Bugatti-Rimac, combining off-site work in PWT premises in Turin and on-site presence in their facilities in Zagreb, Croatia. The CFD is a widely used tool in the automotive industry, since it allows to simulate the behaviour of different powertrain sub-systems, significantly reducing the issues detection during the testing phase and thus improving the time-to-market and reducing the overall costs. For this reason, GT-SUITE has been chosen for this project: developed by Gamma Technologies, it is a versatile and powerful tool for the 1D-CFD modelling and simulation. The aim of this thesis work is to realize a 1D model of a Carbon Canister, used as an Evaporative Emission Control System (EVAP). This component uses active carbons in the form of pellets or honeycombs to absorb fuel vapours mainly generated in gasoline vehicles tank. The future legislations are becoming more and more stringent also on the evaporative emissions side due to their impact on the environmental pollution, making the simulation of EVAP systems fundamental for OEMs. The starting point was the analysis and measurement of the physical component through the usage of a 3D CAD software. The main dimensions have been implemented in the 1D Model in GT-SUITE, up to the complete building of the virtual model. Several iterations aimed at the improvement of the model have been performed, up to obtaining a flexible model capable of simulate every test conditions. Then, the chemical reaction which governs the absorption and desorption of the fuel vapours have been calibrated to replicate the results obtained through the test performed by the OEM. Finally, the component has been simulated during a Refuelling test, to prove the potentiality of the developed model and methodology.