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利用三维湍流数值模拟对某30°斜轴进水流道水力特性进行了分析,研究了设计流量工况下流道的内部流场、不同横断面和纵剖面速度等值线、出口断面速度均匀度和速度加权平均角以及流道水力损失。研究结果表明,斜式进水流道水流处于均匀渐缩,内部流态良好,无漩涡或脱流,出口断面流速分布均匀度Vu=98.2%,速度加权平均角度θ=88.42°,流道水力损失Δh=5.9cm,流道型线合理。试验研究了30°斜轴模型泵装置能量特性、空化特性和飞逸特性,得到5个叶片角度下模型和原型泵装置能量特性曲线、3个不同叶片角度下空化特性及叶片角-2°下的单位飞逸转速和单位飞逸流量。试验结果表明,模型泵装置最高效率随叶片角度减小而增大,叶片角-4°时的最高效率可达83%,较大范围运行工况下的空化性能优良,飞逸转速安全。研究结果对低扬程泵站水力优化设计具有重要的参考价值。
The three-dimensional turbulence numerical simulation is used to analyze the hydraulic characteristics of a 30 ° inclined axis inlet channel. The flow field, the contour of different cross section and longitudinal section, the uniformity of the exit section velocity, Speed-weighted average angle and run-off hydraulic losses. The results show that the water flow in the inclined inlet flow channel is uniformly tapered, the internal flow state is good, there is no vortex or flow off, the flow velocity distribution uniformity at the outlet cross section is Vu = 98.2%, the velocity weighted average angle is θ = 88.42 °, Δh = 5.9cm, the flow pattern is reasonable. The energy, cavitation and escape characteristics of the 30 ° inclined axis model pump were tested. The energy characteristics of the model and the prototype pump at 5 blade angles were obtained. The cavitation characteristics at 3 different blade angles and the blade angle -2 ° Unit flies speed and unit discharge flow. The experimental results show that the maximum efficiency of the model pump increases with the decrease of the blade angle, and the highest efficiency reaches 83% at the blade angle of -4 °. The cavitation performance is good under large operating conditions and the runaway speed is safe. The research results have important reference value for hydraulic optimization design of low-lift pump station.