Abstract: In a combustion process streams of fuel, oxidant or combinations of fuel and oxidant pass simultaneously through a combustion region over opposite sides of a plate disposed therein having downstream extending convolutions which create pairs of large scale oppositely rotating vortices. These vortices cause the fuel and oxidant to mix rapidly with each other. A recirculation zone is disposed immediately downstream and adjacent the edge of the convoluted plate, and in one embodiment is created by a step-wise discontinuity in the flowpath. The mixing occurs without introducing large momentum losses and, when the mixture is ignited immediately downstream of the convoluted plate, the flame propagates with a larger than normal spreading angle.