Inquiry of pulsanting flames.

Abstract

An experimental study has been conducted with the objective of investigating the effects of combustion driven acoustic oscillations in the emission rates of combustion gases, especially carbon monoxide and nitrogen oxides. The experiments were conducted in two distinct set ups: with a burner inside vertical water-jacketed chamber and with a free flame burner. The fuel was liquified petroleum gas (LPG). The reactant mixture was acoustically excited before the burner exit, by a strategically positioned speaker. The experiments were conducted for 0,l6 g/s of LPG. The main conclusions were: a) the pulsating combustion process produces more uniforrn fuel/air profile than the non pulsating process; b) closet o the stoichiometric equivalence ratio the pulsating combustion process generates higher rates of NOx; c) frequency has strong effect on NOx emission, but pressure amplitude has a weak effect; d ) the presence of acoustic field may change drastically the combustion gas emissions in cornplete diffusion flames or partially premixed flames.