一种测定强旋流中旋进涡核(PVC)的新技术

对于旋流设备中产生的旋进涡核现象（ＰＶＣ），可以利用恒温式热线风速仪测量气流瞬时速度，对速度信号进行滤波和ＦＦＴ变换，从而得到ＰＶＣ的频谱特性。在不同的实验工况下，采用该方法实测了旋风分离器内涡核的运动规律。实验结果表明，ＰＶＣ主要存在于旋风分离器锥体排尘口附近，其基频与入口雷诺数成正比，而在其它区域内，流动则表现为随机湍流。与其它测量方法进行了对比，证明所采用的研究方法是可行的

A NEW METHOD FOR MEASURING PRECESSING VORTEX CORE IN SWIRLING FLOW

Hot wire anenometry (HWA) is used to measure the instantaneous velocity, and the measured data are filtered and transformed by fast Fourier transform (FFT) method to get the frequency of precessing vortex core(PVC). The motion of PVC generated in cyclone separator was measured under different conditions by using this method. The results show that the PVC, whose basic frequency is directly proportional to the Reynolds number in gas inlet, mainly exists at the cone near the dust outlet, and the flows in the other area are random turbulence. The comparison of this method to the other ones already used in investigating the PVC proved that this method is a kind of useful and simple technique to obtain the frequency and amplitude of PVC with good accuracy.\=