Mechanics of Methane Bubbles in Tailings Ponds

该项目将研究气泡如何在尾矿库的不同层中成核和生长。在水层下面形成的类似污泥的物质具有一种被称为屈服应力的物质特性（类似于发胶或酸奶），它允许液体在更传统的液体（如水）流动的地方保持硬度。同样的特性也允许气泡被困在液体中。这个项目提出了气泡是移动还是保持静止的问题，例如，气泡必须达到多大才能移动，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）作为温室气体释放到大气中，所以我们想要估计并可能控制这一机制。我们也有兴趣估计是否会发生灾难性的失败，所有的池塘层都不稳定，释放出气泡作为一种喷发形式。

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.