シャーフローの渦巻の有限な寿命
Björn Hof1, Jerry Westerweel, Tobias M Schneider
1School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK. bjorn@reynolds.ph.man.ac.uk
Nature
|September 8, 2006
まとめ
パイプフローの乱流は持続的ではなく,一時的なもので,寿命はレイノルズ数で指数関数的に増加します. この発見は,一般的な見解に異議を唱え,流体力学を制御する新しい方法を示唆しています.
科学分野:
- 流体力学 流体力学
- トルブルンスの研究
- 非線形ダイナミクス 非線形ダイナミクス
背景:
- 流体の流れは,速度が増加するにつれて,ラミナー状態から乱流状態へと移行する.
- パイプの乱れは,安定した条件下で持続するとしばしば考えられます.
- 以前の研究では,持続的な乱流の発生に際して,臨界のレイノルズ数を示唆していた.
研究 の 目的:
- パイプ内の乱流の持続性を調査する.
- 持続的な乱流の確立された見解に異議を唱えるために.
- レイノルズ数と乱流の寿命の関係を探求する.
主な方法:
- 実験データ収集は,幅広いライフサイズのデータを収集します.
- 流体フローダイナミクスをモデル化するための数値計算.
- ストレートパイプにおける乱流の振る舞いの分析.
主要な成果:
- パイプの乱流の寿命は,臨界レイノルズ数では分岐しない.
- 乱流の寿命は,レイノルズ数で指数関数的に増加します.
- パイプの乱れは,一時的な現象であることが実証されています.
結論:
- パイプの持続的な乱流に関する一般に受け入れられている見解は,挑戦されています.
- パイプフローの渦巻状態とラミナー状態は,ダイナミックに結びついている.
- この一時的な性質から,乱流制御のための新しい道が生まれることがあります.
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