Multi-Scale Two-Phase Bubbly Flow Modeling

Multiphase bubbly mixture flows in pipelines, cooling equipment, reaction towers, and in petroleum, chemical, geothermal and nuclear industries have strong influence on efficiency. The ability to predict the flow behavior accurately is essential in designing energy efficient two-phase flow processing and transporting equipment. One of the major prediction difficulties lies in the complex multiple length-scale nature of such mixture flows. Conventional approaches resolve either macroscopic averaged quantities of the flow or focus on interface tracking of some important flow details and do not address the full flow. Therefore, a comprehensive model, which could resolve simultaneously the important scales, is required. The proposed research will develop a multiscale two-phase flow simulation method capable of accurately representing bubbly flows of various scales. The model will include a continuum based phase-averaged model for the macro-scale and a discrete bubble/particle model for the micro-scales. These will be integrated into a single code that automatically switches between the two models at different times or in different locations of the studied geometry and allows conversion of discrete bubbles into large cavities or into a continuum description and vice versa depending on the bubbles and cavities size evolution. Commercial Applications and Other Benefits: A multiscale approach based on state-of-the-art numerical techniques will result in a commercial code for generalized bubble flow simulations which can accurately capture important characteristics of cavitating and high void fraction multiphase flows. This software will enable researchers in chemical, oil and gas, nuclear, and marine industries to conduct design studies and to improve energy efficiency of their processes and devices. These applications will strengthen the competitiveness of US industries equipped with developed advanced systems