Performance investigation and emission analysis of a diesel engine operated on hydrogen and ammonia
Okumuş, Fatih
This study investigates binary-fuel operation of a single-cylinder diesel engine using hydrogen and ammonia as secondary fuels through comprehensive CFD simulations. The effects of injector hole diameter, injection timing, and injection duration on combustion, performance, and emissions were systematically analyzed under both full- and partial-load conditions. Parametric analyses further revealed that variations in nozzle diameter and injection duration exerted a stronger influence on indicated power and efficiency than intake air conditions. The results indicate that injector geometry strongly influences combustion dynamics. At full load, indicated power averaged 6.0 kW, with the highest value of 6.5 kW obtained in ammonia–diesel operation at the smallest nozzle diameter. At partial load,...
Eco‐efficiency evaluation of diesel engines fueled with diesel–biodiesel–ammonia blends using data envelopment analysis
Okumuş, Fatih | Pehlivan, Davut
An experimental investigation was conducted to evaluate the emission and performance characteristics of a single‐cylinder diesel engine fueled with various combinations of diesel, biodiesel, and ammonia. The test matrix covered 4 biodiesel levels (0%, 20%, 40%, and 100%) and 4 ammonia energy fractions (0%, 20%, 40%, and 60%) across three engine loads (50%, 75%, and 100%), ensuring a comprehensive exploration of dual, and triple‐fuel strategies. A total of 48 distinct fuel scenarios were tested under controlled conditions. The relative efficiency of each configuration was assessed using input‐oriented Constant Returns to Scale Data Envelopment Analysis (CCR‐DEA), where engine efficiency was treated as the desirable output, and CO, CO2, HC, and NOx emissions were considered undesirable outpu...
A REVIEW OF AMMONIA AS A SUSTAINABLE FUEL FOR MARITIME TRANSPORTATION
Okumuş, Fatih | Kanun, Engin
While the maritime transportation sector plays a critical role in the global economy, it also significantly contributes to greenhouse gas emissions. This study examines the energy efficiency, technical feasibility, and environmental impacts of ammonia as an alternative fuel in maritime transportation. The contributions of regulatory initiatives, such as the IMO's Energy Efficiency Existing Ship Index (EEXI) and the EU's FuelEU Maritime initiative, in promoting the use of low-carbon fuels to reduce emissions are discussed. The study evaluates the chemical and physical properties of ammonia, challenges associated with its combustion and production processes, with a focus on integrating renewable energy sources for green ammonia production. Findings suggest that ammonia's low r...
The effects of ammonia addition on the emission and performance characteristics of a diesel engine with variable compression ratio and injection timing
Okumuş, Fatih
Ammonia, future of the carbonless marine fuel, presents significant potential in achieving zero-emission targets within maritime transportation. In this context, this study explores the use of an ammonia/diesel fuel mixture in a diesel engine, employing both experimental and numerical methods. We focus on the impact of injection timing and compression ratio to optimize the engine while using ammonia/diesel mixture in terms of both engine performance and exhaust emissions. The results show a decrease in engine power with an increasing content of ammonia, reaching the lowest power of 4.53 kW at 60% ammonia content. On the other hand, the increase in compression ratio generally enhances engine power. Thermal efficiency shows an increase up to 40% ammonia content, followed by a decline. CO2 em...