Excess Enthalpy Flames

Combustion processes with excess enthalpy are described with examples given. It is shown that different processes, such as heat and mass transfer, phase and chemical changes are involved. Moreover, flames with excess enthalpy can be encountered in a variety of forms such as laminar or turbulent, within homogeneous or heterogeneous systems involving stationary or unsteady processes, with pulse or spin combustion and as cellular flames. It is to be shown that mainly due to the increase in the chemical reaction rates within the combustion zone, the excess enthalpy state can lead to substantial increases in the burning rates, widening the associated flammability limits and modifying the preignition processes. Some applications that can benefit from the use of such flames are outlined.