Characteristic scale of wrinkles in turbulent premixed flames

摘要: The wrinkles have been well known to appear in most turbulent premixed flames. Todetermine the scale of these wrinkles, experimental study was carried out using an open flame burner. effect upstream turbulence on also examined. characteristics were measured by a laser doppler velocimeter and hot wire anemometer. To obtain different characterstics, several types producing grid used, flow velocity changed. In lean propane-air flame, time records temperature signal obtained fine-wire thermocouple analyzed afford scales unburned burned gas lumps. Based scales, defined converted into length velocity. It found that is around 5 mm independently Approximate agreement with value derived previously from correlation signals two thermocouples placed apart each other similar flame. wavelength deduced compared results laminar instability. good spontaneous oscillation front observed only for mixture. These facts suggest although triggers corrugation front, resulting unless additional hydrodynamic disturbances caused gas, determined physicochemical properties itself.