Characteristics of methanol diffusion flames burning under three different configurations with respect to the directions of forced and natural convective flow fields are presented for zero and normal gravity conditions. Combustion of a spherical methanol particle and of a methanol film within a mixed convective environment, have been numerically simulated. The effects of gravity on aiding, opposing and perpendicular flow are presented. The gravitational field considerably changes the flow field, flame shapes and fuel burning rates, especially for the opposing flow case. © 2006 Elsevier Ltd. All rights reserved.