| dc.description.abstract | Global warming is a big problem today, posing risks to communities, security, and the economy. The shipping industries face challenges to become emissions-free in the future. Hydrogen holds promise for achieving zero emissions, especially in maritime transport, meeting energy needs for long journeys. However, safety is vital due to hydrogen's flammability. Manufacturers of TECO 2030 maritime fuel cell systems are exploring whether to use large-diameter vent pipes for low hydraulic resistance or use small diameter pipes to create high velocity jets during venting. This choice can be through theoretical, numerical, and experimental methods. Numerous relevant studies and numerical simulations using Computational Fluid Dynamics (CFD) have be conducted.
In this thesis, low momentum jets out of the vent mast are selected. The numerical simulations using CFD are performed. The geometry and certain simulation parameters are extracted from one of the scientific articles I studied. The focus of this report is on hydrogen gas emissions with a low-momentum jet discharged from the vent mast pipe. The investigation revolves around how varying wind speeds (0 m/s, 2.5 m/s, 5 m/s, and 10 m/s) impact the dispersion of the released gas within the defined domain.
In this project, the RANS (Reynolds-averaged Navier-Stokes) numerical method and the k-omega (ω) SST (Shear Stress Transport) turbulence model are chosen. OpenFOAM 10 (Open-source Field Operation And Manipulation) software is selected as the CFD tool. The BuoyantReactionFoam solver within OpenFOAM 10 is used. Four different scenarios simulated by varying the wind speeds within the specified domain.
By analyzing the four cases simulated, the results show that the CFD software OpenFOAM 10 and the BouyantReactionFoam solver are useful and effective for the simulations. The outcomes from simulations reveal that with a low-momentum jet out of the vent mast, the wind velocity significantly influences the speed of the released gas clouds. The findings depict H2 volume in the released gas clouds are affected by different wind speed. The effects also display the released H2 gas clouds with a volume fraction of 0.3 with low momentum can be lifted by the blowing wind. | |