Influence of multiphase microstructure and rheology on the dynamics of bubble growth and release from viscoelastic soft sediments

在许多自然和工程系统中，软沉积物中捕获气体的生长、保留和释放至关重要；从水上水库泥床和废水污泥中甲烷的形成，到受腐蚀的遗留核废料中氢气释放的安全问题。这个项目将通过研究粘弹性沉积物中气泡的生长和释放机制来显著增强我们对这些系统的了解。特别是，我们将重点描述沉积物微结构(例如孔隙度)和流体流变学之间的相互作用，包括初始单个气泡生长的动力学、相互连接的气泡网络的二次形成以及由此对连续气体释放的影响。该项目将把最先进的X射线CT测量和可视化数据分析与格子-波尔兹曼和蒙特卡洛技术相结合，以模拟气体在多孔网络中的流动(例如，见图)，以及将沉积物流变性与气泡生长动力学联系起来的分析建模。该项目是与英国最大的核运营商Sellafield合作的，成果可应用于自然沉积学、颗粒工程和复杂流体科学。

The growth, retention and release of trapped gas within soft sediments is critically important in many natural and engineered systems; from methane formation within the muddy beds of aquatic reservoirs and wastewater sludges to safety concerns from hydrogen gas release in corroded legacy nuclear wastes. This project will seek to significantly enhance our knowledge of these systems, by examining the mechanisms of bubble growth and release in viscoelastic sediments. In particular, we will focus on characterising the interplay between sediment microstructure (e.g. porosity) and fluid rheology on the dynamics of initial single bubble growth, secondary formation of interconnected bubble networks and the resulting influence on continuous gaseous release. The project will combine state-of-the-art x-ray CT measurements and visual data analysis with Lattice-Boltzmann and Monte Carlo techniques to simulate gas flow through porous networks (e.g. see Figure) as well as analytical modelling to link sediment rheology to bubble growth dynamics. The project is a collaboration with Sellafield, the U.Ks largest nuclear operator, with outcomes transferrable across natural sedimentology, particle engineering and complex fluid sciences.