A CFD approach for the flow regime transition in a gas-liquid vane-type separator


A CFD approach for the flow regime transition in a gas-liquid vane-type separator

Yin, J.; Zhang, T.; Krull, B.; Meller, R.; Schlegel, F.; Lucas, D.; Dezhong, W.; Liao, Y.

Two-phase flows generally occur with various flow regimes, even in fixed geometries. The transition from one regime to another requires careful numerical modeling. In vane-type gas-liquid separators, the transition from bubbly flow to stratified flow is the dominating phenomena. This paper describes the application of a morphology adaptive hybrid multi-field model (OpenFOAM-Hybrid) to predict the complex flow in such vane-type separator, covering different regimes and the corresponding transitions. By means of OpenFOAM-Hybrid, the coexistence of dispersed bubbles and continuous gas core is modelled simultaneously with the same set of equations. The key issue here is the definition of a morphology transition criterion describing the formation of continuous gas out of dispersed gas. Such a transition criterion, based on the local volume fractions of the dispersed and the continuous gas phase, is proposed. It combines coalescence and absorption transfer processes. This model is added to OpenFOAM-Hybrid and validated by predicting both gas bubbles and a continuous gas core as well as transitional regimes in the vane-type separator. The gas core morphology evolution is investigated in detail. OpenFOAM-Hybrid is capable of capturing the gas core dynamics in the vane-type separator and thus proves to be a reliable predictive tool.

Keywords: gas core stability; multi-scale interface; multi-field simulation; swirling flow; OpenFOAM

Permalink: https://www.hzdr.de/publications/Publ-34688
Publ.-Id: 34688