偏离设计工况时离心泵内部流场的数值模拟

通过高效数值模拟的方法分析通流部分的气动性能,对叶轮进行优化改进,扩容改造,从而提高效率,可靠性,安全性.主要采用FLUENT,在双参考坐标系下,利用有限体积法对雷诺时均Navier-Stokes方程进行数值离散,选用标准k-s湍流模型,SIM-PLEC方法求解,对原模型泵进行非设计工况下内部流场的叶轮和蜗壳的耦合数值模拟,主要是变转速和变流量调节.得出变转速调节下全流场的速度和压力分布均与原模型相似,但转速过低时则出现明显不同;变流量模拟时,无论是大流量还是小流量,在叶轮流道和蜗壳区均出现了较为严重的回流和漩涡区,并对这一现象进行了分析.最后对原模型蜗壳提出了一些改造意见,指出了偏心蜗壳在蜗舌处的回流情况较对称蜗壳好一些.

Centrifugal Pump Deviate from Design Conditions Numerical Simulation of Internal Flow Field

Through the efficient numerical simulation, the analysis of the aerodynamic performance of the flow section, the improvement of the optimized impeller,the expansion of the transformation are used to improve efficiency, relability and safety. FLUENT, a double reference frame,the finite volume method on the time averaged Navier-Stokes equations numerical dispersion, the standard k-s turbulence model, SIMPLEC method are use to solve the original model for non-design conditions within the pump impeller and volute flow coupling numerical simu- lation. Mainly variable speed and variable flow control, the velocity and pressure distribution of the full flow field under the variable speed adjustment are found to be similar to the original model. But when the speed is too slow, there is obviously different. Variable flow simulation, of whether big or small traffic flow, in the impeller and the volute area suffered from a more serious back and whirlpool area. This phenomenon is analyzed. Finally, a number of modified opinions is given for the original model, one of which is that the back - flow condition of the eccentric spiral in the snail tongue department is better than the symmetric.