Toward Improved Closure Relations for the Turbulent Kinetic Energy Equation in Bubble‐Driven Flows

Abstract

There is a considerable interest within both academia and industry to develop improved computational fluid dynamic methods for gas-liquid flows in bubble columns in order to support their scale-up and optimal design. One main model limitation in current Eulerian two-fluid and multi-fluid models concerns adequate closure relations for turbulence in bubble-driven flows. This article highlights some special features of bubble-induced turbulence, discusses shortcomings of common concepts for closure of the liquid phase turbulence kinetic energy equation and presents an approach for development and validation of improved models. Some problematic issues related to the direct numerical simulation of bubble swarms in narrow bubble columns are also discussed.

A Note on Modeling the Effects of Surfactants on Bubble‐Induced Turbulence

“…The development and validation of improved statistical turbulence models for dispersed bubbly flows is a long‐term task which requires an integrated approach involving various experiments and computational methods (DNS, EE‐RANS) on different configurations (single bubbles, bubble swarms) with or without background flows 2. The present study is such a combined step towards this goal.…”

“…A strong emphasis of the MMPE conference is put on application‐oriented research, bridging the gap between scientific findings and methodology and the requirements of industry 1. In this context our investigation aims on the assessment of the Reynolds‐averaged Navier‐Stokes (RANS) modeling for BIT 2, 3. Such models are required for computation of large‐scale multiphase reactors such as bubble columns, embedded in the Euler‐Euler (EE) framework 4–10.…”

Study on bubble-induced turbulence in pipes and containers with Reynolds-stress models

“…These mechanisms can significantly affect the interfacial processes, such as bubble coalescence and breakup (Liao et al, 2014;Liao, 2020;Qi et al, 2020) and interphase momentum transfer (Lucas et al, 2016;Michaelides et al, 2016;Sommerfeld, 2017). Hence, providing an improved representation of some of these mechanisms is the goal of the turbulence modelling development for bubbly flows (Wörner and Erdogan, 2013;Lucas et al, 2015).…”