To research the effects of the blade outlet angle on the performance and the radial force of the marine pump, the unsteady numerical simulation of the four different models is carried out. The radial forces on the impeller and the blades are obtained under different flow rate conditions. The time and frequency domain characteristics of radial resultant force on the impeller and the blades are analyzed and those of the impeller torque are researched. The results show that the radial forces of the impeller and the blades increase with the increase of the blade outlet angle at the same flow rate. With the same blade outlet angle, the radial forces decrease with the increase of the flow rate. The roundness of radial force vector diagram becomes more obvious with the decrease of the blade outlet angle. The root mean square (RMS) of radial force on the blades is about 30% of that on the impeller. The main frequency of radial force on the impeller and the blades is the axial passing frequency (APF), and that of impeller torque is the blade passing frequency (BPF), and there are peaks at the blade frequency multiplier. At the same flow rate, the main frequency and maximum fluctuation amplitudes on the impeller and the blades increase with the increase of the blade outlet angle. Meanwhile, the impeller torque increases with the increase of the blade outlet angle. With the same blade outlet angle, the main frequency, maximum fluctuation amplitudes, and the impeller torque decrease with the increase of the flow rate. The amplitude difference decreases with the increase of the flow rate. The blade outlet angle has an obvious greater influence on the radial forces and fluctuation at the small flow rate. The vibration test shows that the vibration intensities of model 25 and model 35 are less than 2.5 mm/s, and the vibration intensity of model 25 is about 0.2 mm/s less than that of model 35.

中文翻译：

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叶片出口角度对船用磁力泵径向力的影响

为了研究叶片出口角度对船用泵性能和径向力的影响，对四种不同模型进行了非稳态数值模拟。叶轮和叶片上的径向力是在不同流速条件下获得的。分析了叶轮和叶片上径向合力的时域和频域特性，并研究了叶轮扭矩。结果表明，在相同流量下，叶轮和叶片的径向力随叶片出口角的增加而增大。在相同的叶片出口角度下，径向力随着流量的增加而减小。随着叶片出口角的减小，径向力矢量图的圆度变得更加明显。叶片径向力的均方根（RMS）约为叶轮径向均方根的30％。叶轮和叶片上的径向力的主要频率是轴向通过频率（APF），叶轮扭矩的主要频率是叶片通过频率（BPF），并且叶片倍频处存在峰值。在相同的流量下，叶轮和叶片上的主频率和最大波动幅度随叶片出口角的增加而增加。同时，叶轮扭矩随着叶片出口角度的增加而增加。在叶片出口角度相同的情况下，主频率，最大波动幅度和叶轮扭矩随着流量的增加而降低。振幅差随着流量的增加而减小。叶片出口角度在小流量下对径向力和波动具有明显的更大影响。振动测试表明，模型25和模型35的振动强度小于2.5 mm / s，模型25的振动强度比模型35的振动强度小0.2 mm / s。