Perpustakaan Digital ITB

Despite their environmental impact, the global energy demand continues to rely heavily on nonrenewable energy sources. To achieve a sustainable future, developing renewable energy sources is essential. Ammonia (????????3) is a promising alternative due to its high hydrogen density and efficient transportability. Experimental studies on ammonia combustion lag behind those of carbon-based fuels, leading to gaps in understanding its risks and mitigation strategies. Additionally, ammonia's low laminar burning flame speed poses practical challenges. Mixing hydrogen (????2) with ammonia can help achieve a flame speed comparable to that of conventional hydrocarbon fuels. Traditional fuel combustion experiments are costly and require advanced equipment, making them less feasible. This project will use numerical methods to conduct premixed Ammonia-Hydrogen-Air combustion. Using OpenFOAM, an open-source Computational Fluid Dynamics (CFD) software, this research employs Large Eddy Simulation (LES) to capture detailed flame characteristics. The project compares RANS and LES methods, evaluates four chemical mechanisms: Kaust, Otomo, Tomoaki, and GRI 3.0, and examines the effects of reducing chemical mechanisms, also various equivalence ratios. Simulations are conducted using a reference burner. The findings indicate that LES is superior in generating turbulence and species distribution which is shown by the more distributed Q-criterion value. The Otomo mechanism is the most accurate compared to an experimental value, which generates 800 to 1200 dry PPM. The equivalence ratio of 0.8 produces the most NO emissions with a generation of 1200 PPM, and reducing mechanisms is not preferable because it increases NO emission up to 33%.