Influence of e-fuel usage on flow conditions in diesel engine injectors

Namen magistrskega dela je ugotoviti vpliv e-goriva na tokovne razmere v vbrizgalni šobi dizelskega motorja. Alternativna goriva imajo drugačne lastnosti od konvencionalnega dizelskega goriva. Posledično lahko pričakujemo različno obnašanje goriva v vbrizgalni šobi. V magistrski nalogi so primerjana tri goriva. To so e-FT gorivo, My Renewable Diesel in konvencionalno dizelsko gorivo. Analiza toka goriva je bila izvedena s pomočjo programske opreme AVL FIRE, kjer so bile izvedene tri simulacije, za vsako gorivo posebej. Simulacija je bila omejena na enako geometrijo vbrizgalne šobe, enak potek dviga igle, enak obratovalni režim motorja, enak tlak vbrizgavanja in enak tlak znotraj zgorevalne komore. Po končanih simulacijah smo spoznali, da lastnosti goriva vplivajo na tokovne razmere in razvoj parne faze. Viskoznost in gostota sta tesno povezana z razvojem parne faze ter s pojavom kavitacije. Višja kot sta viskoznost in gostota goriva, manjša je možnost pojava kavitacije ter manj je parne faze. To pomeni, da manj viskozna goriva bolj kavitirajo v primerjavi bolj viskoznimi.The purpose of this master\u27s thesis is to investigate the impact of e-fuel on the flow conditions in the injection nozzle of a diesel engine. Alternative fuels have different properties compared to conventional diesel fuel. Consequently, we can expect different fuel behavior in the injection nozzle. We compared three different types of fuels. The fuels compared are e-FT, My Renewable Diesel and conventional diesel fuel. Fuel flow analysis was made with software package AVL FIRE, where three simulations were conducted for each fuel separately. The simulation was limited to the same geometry of injection nozzle, the same needle lift profile, the same engine operating conditions, the same injection pressure, and the same pressure inside the combustion chamber. When the simulations were finished, we found that fuel properties influence the flow conditions and development of the vapor phase. Viscosity and density are closely related to the development of vapor phase and the occurrence of cavitation. Using a fuel with greater viscosity and density results in lower vapor phase and reduce the likelihood of cavitation. This means that less viscous fuels cavitate more compared to more viscous ones