非雙變質帶 的英文怎麼說
中文拼音 [fēishuāngbiànzhídài]
非雙變質帶
英文
decoupling zone of metamorphism-
By comparing the dry plate pressures drop and distributions of velocities simulated on single valve with those of double valves, it was found that there was intense turbulence in the flow fields around fixed - valve, there were eddy areas between valve side orifices and tray wall, there were eddies above the valves too, these led to the complex behaviors of gas perforating valve, these had a great effect on the gas - liquid mass transfer process. at the same time, in order to prevent the disadvantageous effect of gas between one valve with another on the gas - liquid mass transfer, it was very effective to change the fields of gas perforating valve by folding the edges of valve
通過對數值模擬得出的單閥和雙閥塔板的干板壓降及流場速度分佈分析對比后發現，固定閥周圍流場存在較強的湍動，閥側孔與塔板壁面區域以及閥體的上方空間存在明顯的渦流區，使氣體穿閥后的行為變得復雜，並對氣液傳質過程產生重大影響；模擬結果表明，為防止和削弱固定閥間的對沖造成的「死區」對傳質帶來的不利影響，通過折邊來改變氣體的氣路是非常有效的，模擬值與實驗值基本得到吻合。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。
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