| Zugriffsnummer | 41823 |
| Dokumenttyp | Konferenzartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Validation of multiphase flow simulations by comparison with experimental video observations |
| Autor(in); Institution |
Schmelter, Sonja; 8.4, Mathematische Modellierung und Datenanalyse, PTB-Berlin
|
| Quelle/Jahr | North Sea Flow Measurement Workshop, 22-24 October 2018: Technical Paper:(2019), 11 S. |
| Availability | [online only] |
| URL | |
| Konferenzangaben | 36th NSFMW - "36th North Sea Flow Mesurement Workshop", Aberdeen, 22-24, October, 2018, UNITED KINGDOM |
| Freie Schlagworte | Multiphase flow simulation ; slug flow ; liquid level extraction ; refraction correction ; spectral analysis ; comparison with experiment ; PTB high performance compute cluster |
| Zusammenfassung | ne central aim of multiphase flow metrology is to evaluate and reduce the uncertainty in multiphase flow metering in the oil and gas industries. While for single-phase flow metrology there exists a well-established reference network with norms and standards, such a network is lacking for multiphase flow metrology. This leads to a high level of uncertainty in multiphase flow measurement systems reaching up to 20%. To reduce this level of uncertainty, the process of flow pattern formation as well as the quantitative influence of relevant flow condition parameters are investigated by computational fluid dynamics (CFD) since CFD gives insight into areas that are hardly accessible by experiments. In this contribution, we show simulation results for gas-liquid flow through a horizontal pipe with diameter D = 0.104 m and length L = 16 m. Six test cases with different oil, water, and gas flow rates are considered, see Table 1. These test cases are classified as slug flow. Figure 1 shows the simulated gas volume fraction after ca. 40 seconds in a vertical cross section at the end of the pipe for one of the nitrogen-water test cases. The numerical predictions are validated by comparison with experimental data obtained from video observations, which have been recorded during the MultiFlowMet I project, see, at the National Engineering Laboratory (NEL). For the quantitative evaluation of the experimental observations, a tool for video analysis has been implemented, which extracts the liquid level over time from the recorded video observations. Figure 2 shows the mean and standard deviation of the extracted liquid level for the considered test cases compared to the corresponding simulation results. One observes that a higher superficial liquid velocity leads, as expected, to a higher liquid level in the pipe. For the mean liquid level, the absolute error between experiment and simulation is less than 0.067 for all cases. However, the standard deviation of the liquid level in the simulation is smaller than in the experiments. For a more detailed comparison between experimental and simulation data, further relevant parameters characterizing flow patterns are compared. Figure 3 shows the first five dominant frequencies of the fast Fourier transform (FFT) for the different test cases. Even though the observed slug frequency (which can be determined by counting slugs, for example) usually cannot directly be identified with the highest frequencies obtained by frequency analysis, neither in the experiment nor in the simulation, these parameters nevertheless provide a quantitative description of the dynamics of the multiphase flow. For both, experiment and simulation, one observes an increase of the dominant frequencies if the ratio of superficial liquid and superficial gas velocity is increased. |
| Themenbereich der Metrologie | Mathematik und metrologische Informationstechnik |
| Forschungsprojekt | 16ENG07: MultiFlowMet II: Multiphase flow reference metrology |
| Förderinformationen (1) |
Förderername: European Commission (EC)
Förderer ID: 0000 0001 2242 8989 Förderer ID Typ: ISNI Förderprogramm: EMPIR 2016 Energy Titel der Förderung: 16ENG07: MultiFlowMet II: Multiphase flow reference metrology Förderungsnummer: 16ENG07 |