通頻帶脈動 的英文怎麼說
中文拼音 [tōngbīndàimàidòng]
通頻帶脈動
英文
passband ripplee-
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。The former one is a product of the pressure pulsation resulting from the fan blade periodically cutting the air, with the blade passing frequency as its base frequency and accompanied by higher harmonics. the wide - band turbulent noise is formed when the rotating fan forces the surrounding air to produce turbulent throw - outs and results in gas thickening and thinning processes
旋轉噪聲是由於風扇的葉片周期性地切割空氣，引起空氣的壓力脈動產生的，以葉片通過頻率為基頻，並伴有高次諧波。湍流噪聲是由於風扇運動導致的周圍空氣發生湍流脫體，使空氣發生擾動，形成氣體的壓縮與稀疏過程而形成的，是一個寬頻帶噪聲。
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