CAJ | 학술논문

离心泵叶轮和蜗壳的相对运动,使流体在叶轮和蜗壳内的流动相互干涉,从而引起周期性压力脉动.通过流场计算发现流体在蜗壳内沿叶片出口边绝对速度方向上出现明显的高速区域;通过对蜗壳内压力脉动的监测发现,叶轮每转过一周,蜗壳内的压力呈周期性波动,波峰和波谷的数量与叶片数相同.通过对压力的频谱特性分析,发现压力脉动的主频就是叶片通过频率.应用高频压力传感器测量泵出口法兰附近的压力,通过FFT变换发现测得的信号主频也是泵的叶片通过频率.根据离心泵内动静干涉引起的压力脉动的这一特征,将泵出口法兰处得到的压力脉动作为测量泵转速的原始信号,采用快速傅里叶变换技术对压力脉动信号进行后处理,得到的主频就是离心泵的叶片通过频率,应用该叶片通过频率可实现对泵转速的测量.
리심빙협륜화와각적상대운동,사류체재협륜화와각내적류동상호간섭,종이인기주기성압력맥동.통과류장계산발현류체재와각내연협편출구변절대속도방향상출현명현적고속구역;통과대와각내압력맥동적감측발현,협륜매전과일주,와각내적압력정주기성파동,파봉화파곡적수량여협편수상동.통과대압력적빈보특성분석,발현압력맥동적주빈취시협편통과빈솔.응용고빈압력전감기측량빙출구법란부근적압력,통과FFT변환발현측득적신호주빈야시빙적협편통과빈솔.근거리심빙내동정간섭인기적압력맥동적저일특정,장빙출구법란처득도적압력맥동작위측량빙전속적원시신호,채용쾌속부리협변환기술대압력맥동신호진행후처리,득도적주빈취시리심빙적협편통과빈솔,응용해협편통과빈솔가실현대빙전속적측량.
As relative motion is existing between the impeller and volute, periodical pressure fluctuations is produced by the flow interaction of the impeller and volute.Numerical simulations showed that obvious high speed regions were formed along the direction of the absolute velocity in the casing at the down-stream of the trailing edges.The pressure fluctuations in casing present periodical features,have five peaks and five valleys according to the number of vanes.Frequency spectrum showed that the dominate frequency of the pressure fluctuation was the blade passing frequency.Pressure acquisition in experimental test was executed bya high-frequency pressure sensor installed in the pump outlet flange.FFT technology was used to analyze the measured signals, and it also showed that the dominate frequency was the blade passing frequency.A new technology to measure the pump rotating speed was developed according to the feature of the rotor-stator interaction.The original contents were those pressure signals at the pump outlet.The dominate frequency of the contents was calculated by the technology of FFT, and then the rotating speed was calculated.