counter-rotating radial-radial swirler. Two-dimensional two-component (2D2C) particle
image velocimetry (PIV) measurements are performed at the mid-plane of the jet. Four
different confinement ratios (ie, 10.4, 23.4, 41.6 and unconfined) are considered at a swirl
number of 1.2. The results reveal the presence of a central toroidal recirculation zone
(CTRZ) in all cases extending inside the jet which indicates the existence of an adverse …