El-Mashad Hamed M, van Loon Wilko K P, Zeeman Grietje, Bot Gerard P A
Department of Agricultural Engineering, Faculty of Agriculture, Mansoura University, Mansoura, Egypt.
Bioresour Technol. 2005 Mar;96(5):531-5. doi: 10.1016/j.biortech.2004.06.020.
Rheological properties are important for the design and modelling of handling and treating fluids. In the present study, the viscosity of liquid manure (about 10% total solids) was measured at different shear rates (2.38-238 s(-1)). The effect of temperature on the viscosity at different shear rates was also studied. The results showed that manure has non-Newtonian flow properties, because the viscosity strongly depended on the applied shear rate. The results showed also that manure behaves like real plastic materials. The power-law model of the shear stress and the rate of shear showed that the magnitude of the consistency coefficient decreased while increasing the temperature, with high values of the determination coefficient. Moreover, the results showed that the Arrhenius-type model fitted the temperature effect on manure viscosity very well (R2 at least 0.95) with calculated activation energy of 17.0+/-0.3 kJ mol(-1).
流变特性对于流体处理和加工的设计与建模非常重要。在本研究中，测量了不同剪切速率（2.38 - 238 s(-1)）下液体粪肥（总固体含量约10%）的粘度。还研究了温度对不同剪切速率下粘度的影响。结果表明，粪肥具有非牛顿流动特性，因为粘度强烈依赖于施加的剪切速率。结果还表明，粪肥表现得像真正的塑性材料。剪切应力与剪切速率的幂律模型表明，随着温度升高，稠度系数的大小降低，决定系数的值较高。此外，结果表明，阿累尼乌斯型模型能很好地拟合温度对粪肥粘度的影响（R2至少为0.95），计算得到的活化能为17.0±0.3 kJ mol(-1)。
