Super-mixing combustion enhanced by resonance between micro-shear layer and acoustic excitation

In terms of the application of high-speed and high-load combustion to isothermal-expansion combustion proposed by the authors, flow and reaction control of relatively small diffusion flames ejected from nozzles 0.5 and 1 mm in width are investigated using acoustic resonance; this study is the first step for the mixing control of a micro-diffusion flame which is considered to be a final goal of the relevant studies. In nonreacting jet experiments, Schlieren visualization and flow measurement by a hot-wire anemometer show that marked amplification of turbulence is induced by acoustic excitation with frequencies proportional to the nozzle-exit velocity. Analogously, visual observation, temperature and measurements of concentration for the reacting jet demonstrate that combustion is significantly enhanced under the resonant condition.