(601c) Effect of Inlet Geometry on Gas-Liquid Two-Phase Flow in a Horizontal Pipeline

Two-phase gas-liquid flows are extensively studied due to its large industrial application, such as chemical, petroleum and nuclear industry. This type of flow presents various flow patterns, which depend on operational parameters, physical properties of the phases and geometric configurations. For the same operational conditions, variables as the geometry inlet can change the flow pattern inducing the complex structures formation. An example of it, is the intermittent flow, they are extremely instable and can cause high pressure fluctuations that results in damage in equipment and pipelines. Despite several researches available in the literature, how the flow pattern is affected by different inlet geometries are still subject of study. Thus, the aim of this study is to analyze the effect caused in two-phase flow changing the inlet geometry. Experiments were conducted, with three different inlet geometries, in an experimental facility that consists of a horizontal pipeline with 7 m of length and 74 mm of inner diameter. The fluids applied as gas and liquid were air and tap water, respectively. Acquired data for the analysis was differential pressure sensors signals, installed in the unit. The flow patterns observed according to the operational conditions employed in the experiments are slug, stratified, wavy, and plug flow. Power spectral density (PSD) analysis was performed to identify the dominant frequencies in each condition, which can be associated to the developed flow patterns. Evaluating pressure time series, it was verified that different inlet geometries modify the system signal amplitude. With the inlet changing, distinct flow patterns were identified in the same operational conditions.