Author : Fouad Alwan Saleh and Humam Hassan Hussein

Oxygen enhanced combustion and alternative fuels produced form renewable sources, such as methanol and ethanol consider two important techniques used to minimize the emissions and improve efficiency of the engine. In the experimental part of this study, a measurement system was designed to investigate the effect of methanol addition to gasoline with using oxygen enrichment on the laminar flame propagation. Both optical and tube methods were used to measure the speed of the laminar flame for five blends of methanol/gasoline 0% (M0), 5% (M5), 10% (M10), 15% (M15) and 20% (M20) methanol by volume. The position of flame front was placed utilizing photodiodes. The speed of laminar flame was measured at the laboratory circumstances (at 298 K and 1 atm. initial temperature and pressure, respectively) with three ratios (21, 23 and 25) % by volume of molar oxygen enrichment and for a range of equivalence ratio (ϕ) from 0.7 to 1.4. The tests were conducted at the pre-pressure period. In the theoretical part, the combustion reaction formula for methanol –gasoline blend with oxygen enrichment was presented as a function of blending ratio for stoichiometric, rich and lean mixtures. The flame temperature of all the fuel blends was calculated by making use of the HPFLAME software. Also, this part includes the calculation of laminar burning velocity by using density ratio method. Using oxygen enhanced combustion with methanol/gasoline blending increases the laminar burning velocity, flame speed and adiabatic flame temperature for each blend. Gasoline has the higher values of laminar burning velocity, flame speed and adiabatic flame temperature compared with the other blends. The laminar burning velocity values computed in the present work were found well compatible with the previous reported results for the air, combustion of gasoline, and methanol/gasoline (10% and 20%) by volume methanol.

Keywords: Oxygen-enhanced, Methanol, laminar burning velocity, tube method, flame thickness

Article published in International Journal of Current Engineering and Technology, Vol.9, No.2 (March/April 2019)