侧向进水泵站流态模拟及改善研究

为解决侧向进水泵站前池和进水池内部大范围漩涡问题,以某一具体泵站为工程基础,基于三维不可压缩流体的雷诺时均N-S方程和RNG k-ε湍流模型,采用ANSYS CFX软件对前池和进水池进行数值计算,采用定性方法分析了前池和进水池所选横断面流态,采用定量方法分析了进水池内部所选纵断面特征线上轴向速度均匀度。通过数值计算流线图发现:对于原始方案,水流以斜交形式进入进水池,侧向进水泵站2#至5#进水池右侧边壁处存在大范围回流区域;为改善原侧向泵站进水结构的不良流态,通过多方案整流措施的数值计算,相比于原方案,采用导流墙和立柱相结合的整流措施,前池及进水池内大范围回流区域消失,整流后进水池纵断面特征线上的轴向速度均匀度总平均提高18.15%,最大提高至27.82%。研究成果为改善侧向进水泵站流态提供了参考。

Numerical simulation of side-intake flow for fluid meliorating of pumping stations

In order to solve the problem of large-range vortex within the fore bay and the suction sump of side inlet pumping station， numerical calculationsare made on both the fore bay and the suction sump with the software of ANSYS CFX based on the Reynolds-averaged Navier-Stokes equations for 3-D incompressible fluid and RNG k-ε turbulence model by taking a specific pumping station as the engineering basis， for which the selected flow patterns of the cross-sections for both the fore bay and the suction sump are analyzed with qualitative method， while the axial velocity uniformity on the characteristic line of the selected longitudinal section inside of the suction sump is analyzed with quantitative method as well. It is found out through the streamline chart of the numerical calculation that water flows into the suction sump with the flow pattern of oblique crossing for the original scheme， and then large-range back flow zones are there at the right side-walls from No.2 to No. 5 suction sumps of the side inlet pumping station. Through the numerical calculations made for several flow regulation measure schemes， the flow regulation measure of combining guide-wall with verticalcolumn is adopted， so as to improve the undesirable flow pattern of the water intake structure for the original side inlet pumping station. Compared with the original scheme， the large-range back flow zones inside of both the fore bay and the suction sump disappear. After the flow regulation， the axial velocity uniformity on the characteristic line of the longitudinal section inside of the suction sump is generally increased by 18.15% on average with the maximum increase of 27.82%. The study result provides a reference for improving the flow pattern of side inlet pumping station.