Thermal ignition in buoyancy-driven boundary layer flows along inclined hot plates

[[abstract]]The criterion of ignition of combustible boundary-layer flow over a heated surface is a fundamental problem of combustion theory, tackled by experiment, series expansion, numerical simulation or asymptotic analysis in the limit of large activation energy. Because the behavior of most fires on Earth is governed by buoyancy-induced convection, ignition in boundary-layer flow under natural convection is related not only to ignition phenomena influenced by natural convection on the academic side, but also to the onset of accidental fire on the practical side. Laminar combustible boundary-layer flow along a vertical plate at a high-temperature wall serves as a prototypical problem to assess the effect of natural convection on ignition. The ignition phenomena of combustible boundary-layer flow under purely natural convection at various angles of inclination &thetas; are of interest. The objective of the present work is to obtain an explicit criterion of ignition, which is a function of &thetas;, the Prandtl number, the temperature at the wall and other properties of the combustible gas, by means of an asymptotic analysis in the limit of large activation energy.[[fileno]]2020215010010[[department]]動機