The turbulent burning velocity of methanol-air mixtures

Methanol is a sustainable and versatile alternative fuel for spark-ignition engines and other combustion applications. To characterize the combustion behavior of this fuel, a good understanding of the factors affecting its turbulent burning velocity is required. This paper presents experimental values of the turbulent burning velocity of methanol-air mixtures obtained in a fan-stirred bomb, for u'= 2-6 m/s, phi= 0.8-1.4, T=358 K and pressures up to 0.5 MPa. In combination with laminar burning velocity values previously obtained on the same rig, these measurements are used to provide better insight into the various factors affecting u_t of methanol, and to assess to what degree existing turbulent combustion models can reproduce experimental trends. It appeared that most models correctly accounted for the effects of turbulent rms velocity u'. With respect to the effects of phi and pressure, however, models accounting for flame stretch and instabilities, through the inclusion of model terms depending on thermodiffusive mixture properties and pressure, had a slight edge on simpler formulations.