| Autor(in); Institution |
Olbrich, Marc; 8.4, Mathematische Modellierung und Datenanalyse, PTB-Berlin; Institute of Fluid Dynamics and Technical Acoustics, Technische Universität Berlin, Berlin, GERMANY
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| Zusammenfassung |
Multiphase flow is defined as the simultaneous flow of different phases, such as liquids, gases or solids, and occurs in a variety of industrial and environmental processes. This type of flow poses special challenges for the operators and engineers due to the complex behavior of the phases, which is still subject to intensive research efforts. This applies in particular to gas-liquid pipe flows with its different flow patterns, i.e., categories of spatio-temporal phase distributions. The formation of these flow patterns depend on the fluid properties, the geometry of the pipes and the operating conditions. Several flow patterns with different properties have been identified in horizontal pipes, namely stratified flow, wavy flow, plug flow, slug flow, annular flow, bubbly flow, and mist flow. Due to their intermittent sequence of liquid blocks and large gas bubbles, the slug and plug flow pattern cause various disadvantages for the operating facilities, including higher measurement errors, larger pressure drops, undesired fluctuations in pressure and flow rates, as well as induced vibrations and the associated fatigue of the piping. These flows are encountered especially in the deep sea oil and gas production with its long transportation pipelines. Because of this, it is important to take these intermittent flow patterns into account for the design of multiphase transportation pipeline systems. Therefore, predictive models, numerical simulations, and empirical correlations have widely been used as a starting point for engineering designs. However, due to the complexity of these flow patterns, it is still subject to intensive research to find models, which reliably and accurately predict the flow patterns and their temporal and spatial characteristics for given flow rates, fluid properties, pipe diameters, and inclinations. For the development, calibration and validation of such predictive models, correlations and simulations, methods that provide precise descriptions of these flows are of special interest. This includes the complex intermittent flow patterns, such as slug flow, but also the separated flow patterns, such as stratified or wavy flow, since they often constitute an initial state in the development of the other, more complex flow patterns. |
