2020 Fiscal Year Research-status Report
Understanding flame-acoustic coupling through high-fidelity DNS with detailed chemical kinetics and combustion tube experiments optimized for DNS
| Project/Area Number |
20K22382
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| Research Institution | Tohoku University |
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Principal Investigator |
Dubey Ajit.Kumar 東北大学, 数理科学連携研究センター, 助教 (40872338)
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| Project Period (FY) |
2020-09-11 – 2022-03-31
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| Keywords | Combustion instability / Detonation / Thermoacoustics / Flame acoustic coupling / Knocking / Numerical Simulation / DNS |
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| Outline of Annual Research Achievements |
Combustion and sound interaction create interesting phenomena of dancing flames but can also lead to loud noise and failure of various engines. This project aims to get a clear understanding of this dynamics from first principles by comparing experiments and direct numerical simulations (DNS).
Experiments in mesoscale tubes showed complex flame instabilities. Next, we built small scale experiments using combustion tube of length 20 cm and diameter 2 cm suitable for DNS. Instability was affected by ignition energy creating new research direction. New experimental setup is being built to study this. DNS of flame propagation in closed tubes was performed. Next, experiments will be performed with varying ignition energy and DNS will be performed for half-open tube experiments.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
Experiments in long mesoscale diameter tubes revealed that parametric instability observed in wider tubes were suppressed in mesoscale tubes. The generation of thermoacoustic instability is slightly difficult to initiate in small scale experiments particularly in shorter tubes of small diameter. Instability was found to depend on ignition energy of the spark ignition system. The spark ignition generates pressure waves which can also influence the flame instability. This created new directions for research on the effect of ignition energy. New experimental setup was needed to quantify ignition energy in combustion tube experiments. Currently, the setup is being built and experiments will be carried out.
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| Strategy for Future Research Activity |
Experiments with different ignition energy in small scale half-open combustion tube experiments will be performed. Then DNS for flame acoustic interaction in half-open tubes will be performed. Results will be analyzed to get a clear understanding of flame acoustic interactions.
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| Causes of Carryover |
Experiments, simulation and travel for conference
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Research Products
(2 results)
