Fig.10 The 3D waterfall of Reynolds stress components of all observing fields from P1 to P5

In this paper, the turbulence statistics of the swirl flow in a gas-liquid separator is investigated by the stereo PIV method. Five observing regions across the swirl chamber are measured and analyzed. The following conclusions can be made:

1. The evolution of turbulence field is closely related to the development of the flow structure, namely the averaged velocity profiles. Based on the analysis on the turbulent kinetic energy, the turbulent intensity and Reynolds shear stresses, the turbulence field can be in general divided into two zones.

2. All the turbulence quantities presents a decay characteristic from the swirl vane to the recovery vane. The decay is partially due to the wall friction and mostly stemming from the inner mixing of undeveloped swirl flow in the first zone. The anisotropic behavior of the Reynolds shear tensor is featured by the redistribution of the magnitude of each component. In the first zone the radial component is dominant, while the tangential component prevails.

3. A very interesting turbulence structure found in this study is the evolution of the distribution pattern of turbulent quantities. In the first zone, the turbulence is distributed in a single peak style. However, the single peak is transited into double peak in the second zone. The specialty is mainly ascribed to the appearance of the counter-rotating vortex in the central zone of the swirl chamber.

The authors wish to thank the National Natural Science Foundation of China (No.11535009 and No. 11675105) for the financial support. In addition, special appreciation was given to Miss. Ma Yanfei for her generous help in this experimental work.