Samer F. Ahmed
Qatar University, Qatar
Title: Combustion Characteristics of Alternative Gaseous Fuel Mixtures
Biography
Biography: Samer F. Ahmed
Abstract
Global warming and the ever increasing emission levels of combustion engines have forced the engine manufacturers to look for alternative fuels for better engine performance and low emissions. Gaseous fuel mixtures such as natural gas , syngas, and liquefied petroleum gas (LPG) are examples of new alternative fuels that have great potential to be used with combustion engines. Combustion characteristics such as ignition and flame speeds of these alternative fuels should be studied extensively before they are fully employed in engines. Recent published results have shown that high bulk velocities decrease the ignition probability in all locations and for all flames. Ignition is sometimes possible even in locations where there is negligible probability of finding flammable mixture and is sometimes impossible in locations with high probability of flammable flow. Failed ignition has been viewed close to the extinction flow conditions of the flame. Igniting the flame away from the extinction conditions results in 100% ignition probability regardless of the ignition location. However, close to extinction, ignition probability decreases gradually and achieving ignition is not possible at certain locations. Measurements of laminar flame speeds of CH4/LPG-air mixtures have found to be higher than those of pure fuels at the same mixture strength. Moreover, the addition of H2 and O2 to the fuel mixtures increase laminar flame speeds notably, while the addition of CO2/N2 mixture to the fuel decreases laminar flame speeds of CH4/LPG-air mixtures.