市政污泥流变特性及圆管流数值模拟研究

通过对市政污泥粘度测量实验,得到污泥剪切速率与剪切应力关系数据,并且观察到剪切稀化现象;运用分段拟合方法求解出初始屈服应力和临界剪切速率,从而得到全范围污泥流变曲线。在此基础上,建立污泥管流模型并完成计算,计算结果与参考文献中经验公式和实验结果接近。且可知管径、流速以及流动指数对管道流动的影响显著。人口流速不变的条件下,减小流动管径33％,驱动压力增大了152．1％;管径不变条件下,提高人口流速10倍,驱动压力增大了11倍;保持管径和入口流速条件不变,增大流动指数10倍,驱动压力减少了20．2％。

Rheologic properties of municipal sludge and a numerical simulation of pipe flow based on that

By measuring the viscosity of municipal sludge, the relationship data of the shear rate and shear stress of sludge were obtained, and the shear-thinning phenomenon was observed. The yield stress and critical shear rate were simultaneously solved by parallel sub-fitting method, and then a full range of sludge flow curve was gained. The results, which numerical simulation of pipe flow sludge through establishing a simplified model, were close to the empirical formula and experimental results of references. And we founded that diameter, flow rate and flow index have significant effects on the pipeline flow. When other conditions remain unchanged, reducing the flow diameter of 33% can lead driving pressure to increase 152.1%, and increasing the flow rate 10 times can lead driving pressure to increase 11 times, as well as increasing the flow index 10 times can lead driving pressure to decrease 20.2%.