Flashing Flows
Flashing flow is a common fluid phenomenon that involves a phase change from liquid to vapour due to a sudden reduction in pressure. It is found in many chemical process industries and understanding this type of flow regime is critical in the design of safe and reliable piping systems.
CFD Design & Engineering has developed 3D numerical models to predict industrial flashing flow in conjunction with the alumina refinery, Rusal Aughinish.
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Applications |
Validation |
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The application of the flashing flow model to an industrial piping system is shown above, coloured by vapour fraction. Flash Vessels and Tanks can also be modelled. Modelling flashing flows with CFD enables greater understanding of the system and enables investigations into:
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The example above shows water flashing to vapour in a converging-diverging nozzle. The pressure drops below the saturation pressure at the nozzle throat and vapour bubbles nucleate and grow. The flashing flow subroutine has been sucessfully validated against a range of experimentment data with excellent agreement. A comparison of the predicted vapour fraction and pressure to experimental data is shown in the chart below. |
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calculation of mass flow 
