Study on the flow structure and its effects on the interaction and formation of cryogenic taylor bubbles by PIV technique and POD analysis



The flow structures around continuous cryogenic Taylor bubbles in the concentric glass tube with different diameters were investigated using particle image velocimetry (PIV) technique under various inclination angles. Optical distortions produced by tube curvature and the refractive index differences between tube and fluid were corrected using ray tracing method. Based on the PIV results, the proper orthogonal decomposition (POD) method was used to investigate the effect of flow structure on the interaction of Taylor bubbles through the large-scale turbulent structures of POD modes. Four best-fitted curves for Taylor bubble interaction for different inclination angles were represented. A correlation for Taylor bubble formation was developed with the consideration of turbulence suppression, tube inner diameter, fluid properties, inclination angle, etc. The results demonstrate that the minimum stable distance attains the smallest value at math formula. The correlation for Taylor bubble formation shows good agreement with the experimental data both in the present study and from its references.