Mechanics of Methane Bubbles in Tailings Ponds

这个项目将研究气泡是如何在尾矿库的不同层中成核和生长的。在水层下面形成的类似淤泥的材料具有一种称为屈服应力的材料特性(类似于发胶或酸奶)，使液体在更传统的液体(例如水)流动的地方保持僵硬。这种相同的性质也允许气泡被困在液体中。这个项目提出了气泡是运动还是保持静止的问题，例如，气泡必须变得多大才能运动，我们可以在污泥中捕获多少小气泡，充满气泡的层有多稳定？移动的气泡(甲烷)以温室气体的形式释放到大气中，所以我们想要估计并可能控制这种机制。我们还有兴趣估计是否会发生灾难性的故障，所有的池塘层都会不稳定，并以喷发的形式释放气泡。 这个项目将涉及计算建模、实验室实验和数学分析的组合。这些实验旨在实现对气泡生长/运动的直接可视化。这些和这些模型都将允许我们试验不同的方法来控制允许气体释放的潜在过程，例如阻止生产、限制增长、限制运动。除了涵盖油砂行业感兴趣的实际问题外，这些领域也是流体力学具有挑战性和趣味性的领域。

This project will study how bubbles are nucleated and grow within the different layers of a tailings pond. The sludge-like material formed below the water layer has a material property called a yield stress (similar to e.g. hair gel or yoghurt) that allows the liquid to remain stiff where more conventional liquids (e.g. water) would flow. This same property also allows for bubbles to be trapped within the liquid. This project asks the question of whether bubbles move or remain static, e.g. how big must bubbles become to move, how many small bubbles can we trap in the sludge, how stable would the bubble-laden layers be? Moving bubbles (methane) are released to the atmosphere as greenhouse gases, so we would like to estimate and possibly control that mechanism. We are also interested to estimate whether a catastrophic failure could occur, where all the pond layers destabilize and release their bubbles as a form of eruption. This project will involve a mix of computational modelling, lab experiments and mathematical analysis. The experiments are designed to allow direct visualization of bubble growth/motion. Both these and the models will allow us to experiment with different ways of controlling the underlying processes that allow gas release, e.g. preventing production, limiting growth, limiting motion. As well as covering questions of practical interest for the oil sands industry, these are challenging and interesting areas for fluid mechanics.