ID 311

Numerical Investigation of Surface Tension Effects in Aerated-Liquid Injectors

 

Abstract:

Aerated-liquid injection, or 'barbotage', or effervescent, is one of the injection schemes capable of delivering well atomized sprays. By creating a two-phase mixture inside the injector, aerated-liquid injectors increase the production of small droplets needed for fast vaporization. Recent numerical studies have shown that interface capturing techniques and continuum surface tension force models can adequately resolve the averaged two-phase distribution within the aerated-liquid injector. The current method uses the Tangent Hyperbola Interface Capturing (THINC) method coupled with a conservative continuum formulation for interfacial tension forces. This approach requires the volume fraction to be smoothed prior to computing surface tension forces. A discrete filter with compact support is applied to the volume fraction field, which ensures proper smoothing independent of grid size. Based on the present state-of-the-art numerical simulation capabilities, the objective of the present study is to numerically explore the effects of liquid surface tension on the two-phase flow structures inside the aerated-liquid injector. The proposed numerical efforts help to overcome the experimental challenges, where it is difficult to modify individual physical properties for a given fluid. The present effort simulates the two-phase flow within an inside-out aerated injector design. Results will include time-averaged line-of-sight integrated quantities, iso-surfaces to visualize the two-phase structures, and one dimension line profiles where a baseline case is compared to the previous experimental work. In addition, the mechanisms which drive the two-phase flow stretching across a nozzle’s area reduction will also be investigated.