Advanced experimental and numerical methods for te prediction of complex gas liquid annular flows

用于复杂气液环流预测的先进实验和数值方法

• 批准号: EP/F009194/1
• 负责人: Omar Matar
• 金额: $ 64.5万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF009194%2F1
• 关键词: Advanced; experimental; numerical; methods; te

The proposed work involves an experimental and modelling investigation of vertically downwards gas-liquid annular flows. These are the key components in a wide variety of industrial applications, prime examples of which are, condensers and chemical reactors used in the production of detergents. In the latter case, a liquid feedstock is injected as a film onto the inside of a bundle of tubes and undergoes an exothermic sulphonation by contact with air containing SO3 which flows down the tubes co-currently with the films on the tube walls. To obtain the required quality of the product, the temperature of the reacting liquid must be rigidly controlled; otherwise, undesirable by-products are formed. Industry has made good progress in modelling these systems but such modelling is limited by the complexity of the underlying physics. First, a complex pattern of waves is formed on the interface and these affect the interaction between the gas and liquid and also the reaction and heat transfer processes. Secondly, liquid droplets are torn off the film and react with the SO3 in the gas in an uncontrolled way. Knowing which flow regime occurs under which conditions, and being able to predict the flow regimes in a systematic manner is crucial for the efficient and optimal operation of reactors that exploit downwards annular gas-liquid flows. Whereas vertically upwards annular flows have received considerable attention in the literature (see e.g. the work of Hewitt and Hall Taylor1a, Hewitt1b, Hewitt and Govan1c and Barbosa et al.1d), there has been very little work on vertically downwards annular flows. This is surprising given the early studies of Webb and Hewitt1e, whose work in this area has shown that the interactions between the turbulent gas core and the thin liquid film, particularly when both gravity and interfacial shear are significant, give rise to many complex phenomena and rich dynamics, which are not well-understood. The current state of modelling of downwards annular flows in general is insufficient. Hence, there is a need for a substantially improved understanding of the coupling between the liquid film and gas turbulence through the interfacial stress exerted by the gas onto the liquid which is responsible for wave formation and drop entrainment; achieving such an understanding is the aim of the proposed work. The project proposed here is a well-balanced synergistic approach adopting recent, advanced experimental methods, results of the detailed numerical and analytical studies conducted in other EPSRC-funded projects, EP/D031222 and EP/E021468, unavailable at the time of earlier studies, and advanced theoretical and modelling methodologies to develop efficient and accurate methods for the systematic prediction of flow interfacial behaviour and flow regimes in downwards annular flows.

拟议的工作涉及垂直向下的气液环形流的实验和建模研究。这些是各种工业应用中的关键部件，其中主要的例子是用于生产洗涤剂的冷凝器和化学反应器。在后一种情况下，液体原料作为薄膜注入到管束内部，并通过与含有 SO3 的空气接触进行放热磺化，空气与管壁上的薄膜并流流下管。为了获得所需的产品质量，必须严格控制反应液的温度；否则，会形成不希望的副产物。工业界在对这些系统进行建模方面取得了良好进展，但这种建模受到基础物理复杂性的限制。首先，界面上形成复杂的波模式，这些波模式影响气体和液体之间的相互作用以及反应和传热过程。其次，液滴从薄膜上撕下，并以不受控制的方式与气体中的 SO3 发生反应。了解在何种条件下会出现何种流态，并能够以系统的方式预测流态，对于利用向下环形气液流的反应器的高效和优化运行至关重要。虽然垂直向上的环形流在文献中受到了相当多的关注（例如参见 Hewitt 和 Hall Taylor1a、Hewitt1b、Hewitt 和 Govan1c 以及 Barbosa 等人的工作），但关于垂直向下的环形流的工作却很少。考虑到 Webb 和 Hewitt1e 的早期研究，这是令人惊讶的，他们在这一领域的工作表明，湍流气体核心和薄液膜之间的相互作用，特别是当重力和界面剪切都很显着时，会产生许多复杂的现象和丰富的动力学，而这些现象和动力学尚不清楚。目前对向下环形流动的建模总体来说是不够的。因此，需要通过气体施加到液体上的界面应力来显着改善对液膜和气体湍流之间的耦合的理解，该界面应力负责波的形成和液滴夹带；达成这样的理解是拟议工作的目标。这里提出的项目是一种均衡的协同方法，采用了最新的、先进的实验方法、早期研究时无法获得的其他 EPSRC 资助项目 EP/D031222 和 EP/E021468 中进行的详细数值和分析研究的结果，以及先进的理论和建模方法，以开发高效、准确的方法来系统预测流动界面行为和流动 向下环形流动的状态。

项目成果

Three-dimensional convective and absolute instabilities in pressure-driven two-layer channel flow

• DOI: 10.1016/j.ijmultiphaseflow.2011.05.005
• 发表时间: 2011-10
• 期刊: International Journal of Multiphase Flow
• 影响因子: 3.8

Application of Proper Orthogonal Decomposition to the morphological analysis of confined co-axial jets of immiscible liquids with comparable densities

• DOI: 10.1063/1.4900944
• 发表时间: 2014-11
• 期刊: Physics of Fluids
• 影响因子: 4.6
• 作者: G. Charalampous;Y. Hardalupas

Two- and three-phase horizontal slug flow simulations using an interface-capturing compositional approach

• DOI: 10.1016/j.ijmultiphaseflow.2014.07.007
• 发表时间: 2014-12
• 期刊: International Journal of Multiphase Flow
• 影响因子: 3.8
• 作者: D. Pavlidis;Zhihua Xie;J. Percival;J. Gomes;C. Pain;O. Matar

Simultaneous planar measurement of droplet velocity and size with gas phase velocities in a spray by combined ILIDS and PIV techniques

• DOI: 10.1007/s00348-009-0802-7
• 发表时间: 2010-01
• 期刊: Experiments in Fluids
• 影响因子: 2.4
• 作者: Y. Hardalupas;S. Sahu;A. Taylor;K. Zarogoulidis

Interfacial stability in turbulent pressure-driven channel flow

湍流压力驱动通道流中的界面稳定性

• 发表时间: 2008
• 期刊: AIChE Annual Meeting, Conference Proceedings
• 作者: Náraigh L.Ó.