Research on the Numerical Effect of VTD Model in Cross Jet

Abstract

To deeply study the specific characteristics of the cross-scale phenomenon of fragmentation and atomization in the cross-jet process, this paper is based on the adaptive grid technology, using the RANS model, RNG k-ε model, LES model turbulence models, and VOF models, DPM model, VTD model multiphase flow models have carried out numerical calculations on the lateral jet process, and compared and analyzed the results to better solve the cross-scale problem and obtain more suitable research methods for the phenomenon of lateral jet breaking and atomization. It is found that: compared to the RANS model and RNG k-ε model, the LES model is more suitable for jet breaking; compared with the VOF model and DPM model, the VTD model is closer to the actual physical phenomenon in the cross jet breaking shape, and the initial surface of the liquid column is broken, the columnar broken and the band-shaped liquid filament is broken by a series of broken and atomized phenomena. And a large number of banded or filamentous liquid lumps can be captured in the continuous liquid film stage and the primary crushing stage of the jet, while discrete misty droplets can also be captured in the secondary crushing area. Based on this, this paper finds that the cross-scale VTD model is combined the phase gradient adaptive grid technology can couple the advantages of the VOF model and the DPM model to better solve the transition problem between the continuous phase and the discrete phase, thereby obtaining more accurate jet atomization characteristics.