centre angle

The problem is studied firstly that the performance characteristics of pump be affected specifically by the four kinds of geometrical parameters of impeller, i. e. number of blade, outlet blade angle, tangential blade thickness and centre angle in this article using the orthogonal experimental method.

作者运用正交试验法，进行了叶片数，叶片出口安放角、圆周厚度和包角等四种叶轮几何参数对离心泵能量性能影响的试验研究。

Spherical metal tank is measured by light tangent method, and the uncertainty of measurement results is calculated by analysing the centre distance, horizontal angle and left and right tangent distance to the top etc.

环形金属罐的测量采用光切法，通过分析中心距、水平夹角、左右切点天顶距等参数，计算球形金属罐容量测量结果的不确定度。

By the sphere centre, elevation angle and azimuth angle of the gun barrel are obtained.

通过确定球心位置，对炮身管的高低角、方位角进行计算，从而检测火炮调炮的性能。

The results show: ( 1) the distribution of swirling flow field in the said square-shaped separator has a forced swirl in the centre, but a quasi-free swirl near the side wall, and a partial swirl existing in the place of edge-angle.

结果表明：（1）方形分离器内的旋流流场呈中心为强制涡而边壁附近为准自由涡分布，在边角位置存在局部旋涡。