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，软沉积物中捕获的气体的生长、保留和释放至关重要;从水生水库和废水污泥的泥床中的甲烷形成，到腐蚀遗留核废料中氢气释放的安全问题。本项目将通过研究粘弹性沉积物中气泡生长和释放的机制，寻求显着提高我们对这些系统的认识。特别是，我们将专注于表征沉积物的微观结构（如孔隙度）和流体流变学之间的相互作用的动力学的初始单个气泡的增长，二次形成的相互连接的气泡网络和连续气体释放的影响。该项目将结合联合收割机最先进的X射线CT测量和可视化数据分析与格子玻尔兹曼和蒙特卡罗技术，以模拟通过多孔网络的气体流动（例如，见图）以及分析建模，将沉积物流变学与气泡生长动力学联系起来。该项目是与英国最大的核运营商塞拉菲尔德的合作，其成果可在自然沉积学、粒子工程和复杂流体科学中转移。

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.