Flow characteristics of the confined combustion flames of counter dual-stage swirler were analyzed.Research found that,the flow characteristics of the counter dualstage swirler changed with the confinement ratio variation.When the confinement ratio was less than 3.8,the center backflow bubble on this flow field grew longer as the confinement ratio increased,with the growth law the same as that of the center backflow bubble on the single-stage swirler flow field.However,as the confinement ratio continued to ...