Numerical study of water effects on the laminar burning velocity of methanol

Using light alcohols in spark-ignition engines can improve energy security, engine performance and pollutant emissions. Methanol has gained popularity due to its ease in production compared to ethanol. Methanol could absorb water easily. In the present work, the adiabatic laminar burning velocity of methanol containing water is investigated both experimentally and numerically. Numerical simulations using CHEMKIN-PRO were undertaken to predict the burning velocities of six mixtures with different water volume fractions (up to 0.6) from the latest San Diego chemical-kinetic mechanism. The burning velocities of three mixtures with different water volume fractions (up to 0.4) were measured using a constant volume vessel and a Schlieren imaging system for a wide range of temperature (380-450 K), pressure (100-400 kPa) and equivalence ratio (0.7-1.4). Results showed a decrease in burning velocity with pressure and an increase with temperature. Water as a diluent led to reduction of the burning velocity. The chemical-kinetic mechanism over predicts the burning velocity.