The Characteristic of Flow Field and Emissions of a Concentric Staged Lean Direct Injection(LDI)Combustor

The characteristic of flow field and emissions was investigated by numerical simulation for a concentric staged lean direct injection combustor,the non-reaction and reaction flow fields were studied under idle and takeoff conditions,and the effect of combustion heat release on flow field was analyzed,then the influence of injection angle on emissions were obtained.The investigation results indicated that the steady central recirculation zone could be formed under non-reaction and reaction conditions by medium swirl strength which the swirl angle is 32°,however,the size and reverse mass flow at reaction conditions is significantly increased than non-reaction conditions;the combustion reaction zone moves toward the outlet as the decrease of fuel injection angle,which reduce the resistant time of hot gas in combustor,and then the production of nitrogen oxides would be decreased.