尾波頻譜 的英文怎麼說
中文拼音 [wěibōbīnpǔ]
尾波頻譜
英文
coda spectrum- 波 : Ⅰ名詞1 （波浪） wave 2 [物理學] （振動傳播的過程） wave 3 （意外變化） an unexpected turn of even...
- 頻 : Ⅰ形容詞（次數多） frequent Ⅱ副詞（屢次） frequently; repeatedly Ⅲ名詞1 [物理學] （物體每秒鐘振動...
- 譜 : Ⅰ名詞[書面語]1 （按類別或系統編成的書或冊子等） table; chart; register 2 （指導練習的格式或圖形）...
- 頻譜 : frequency spectrum; frequency content; spectrum; power density spectrum; power spectrum; [系統] s...
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In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal, wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station, in which the signal is decomposed into different frequency band, and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基於李家峽水電站雙排機組振動的現場試驗研究，並且針對傳統頻譜分析方法傅立葉變換（ fft ）對于非平穩信號已力不從心這一缺陷，利用小波分析方法在時域和頻域上同時具有良好的局部化性質，通過對開停機這一典型非平穩過程信號進行小波及小波包分析，將其分解到不同頻帶內，獲取微弱信息和提取優勢頻率，並對其作振源分析，得出開停機初始時刻因水流不穩均出現強烈的振動現象，且低頻段信號能量最大，開停機過程水流脈動壓力和尾水渦帶擺動是引起定子基礎振動的主要原因。Flow separation produces pressure fluctuations of large amplitudes, possibly with the dominant frequencies differ from up - stream blade wake passing frequency and its harmonics
尾緣氣流分離產生的壓力波動頻譜中含有上游葉片尾跡頻率及其倍頻的分量，但其頻譜可能比較復雜，並非單一地受上游葉片尾跡影響。
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