论文部分内容阅读
二维(双色)激光测速仪(LDA,以下文中用此简称),成功地用来测定混流泵气动模型叶轮后的旋转流场。该气动模型在特性曲线上最佳效率点运行,在旋转流场中一些固定点上测定轴向和周向速度的平均值和均方根值,用专用的数据采集系统将速度的变化和旋转的参考座标连系起来。沿流线安排4个测点以得到横切线,每一横切线包括主流和气动模型泵壳边界层中的二点。发现了一些有趣和重要的特性,其中包括转子叶片所形成的旋转的尾流的结构和发展,泵壳边界层的性质和其中复杂的流动,以及尾流和边界层的相互作用。所用符号 C——翼展中部转子叶片的弦长; r——测量点的径向座标; s——叶片节距; Vi——气体速度分量; Vz,Vu——轴向和周向(切向)速度分量; W——平均绝对速度; X——弧段位置; Z——测量位置的轴向座标。
A two-dimensional (two-color) laser velocimeter (LDA, hereinafter referred to as the LDA) was successfully used to determine the rotational flow field behind the impeller of the aerodynamic model mixed flow pump. The aerodynamic model operates at the optimum efficiency point on the characteristic curve and measures the mean and root mean square values of the axial and circumferential velocities at some fixed points in the rotating flow field. Using a dedicated data acquisition system, the speed change and rotation The reference coordinates of the link. Four measuring points are arranged along the flowline to obtain a cross-cut line, each including two points in the boundary layer of the casing of the mainstream and the aerodynamic model. Some interesting and important features were identified including the structure and development of the rotating wake formed by the rotor blades, the nature of the shell boundary layer and its complex flow, and the wake and boundary layer interactions. Symbol used C - chord length of the middle rotor blade in the span; r - radial coordinate of the measurement point; s - blade pitch; Vi - gas velocity component; Vz, Vu - axial and circumferential Tangential) velocity component; W - average absolute velocity; X - arc position; Z - axial coordinate of measured position.