Oil and gas extraction is a classic field of application for heat and fluid engineering, as highly complex flow phenomena occur within vast pipeline systems. A well-known phenomenon is the severe cooling of highly compressed gases as they flow past obstructions in pipelines, such as sudden changes in pipe diameter, bends, valves, slide gates, and more. This can generate extreme temporal and spatial temperature gradients in pipeline components, which may lead to failure of the surrounding material and, consequently, catastrophic results.
Due to the safety-critical nature of this, Shell possesses years of experience and established standard calculation methods for cooling under various conditions. To further enhance this planning reliability, FlowMotion was commissioned to conduct reference calculations using the commercial CFD (Computational Fluid Dynamics) software, FLUENT. A key aspect of this project was the scientific approach to validation; the influence of all numerical parameters—such as spatial and temporal discretisation, turbulence modelling, and gas laws—was meticulously examined, and the results of the simulations in increasingly complex geometries were compared with existing calculation methods.
Comparing the results of standard calculation methods with CFD outcomes reveals the disadvantage of the one-dimensional approach used by most calculation methods, where all flow variables are averaged across the cross-section. While CFD can also calculate these averaged values, it additionally provides information across the entire computational domain regarding local velocities, pressures, and temperatures, which can exceed the limits for the materials involved.
As a result, CFD calculations represent an important component for enhanced safety.
