Foams generated from viscous non-Newtonian fluids have received insufficient attention in the literature despite their wide ranging industrial applications. We study the steady shear flow and viscoelastic properties of wet foams generated in a continuous multi rotor-stator pilot-scale device. The foams are generated from viscous pseudoplastic liquids consisting of aqueous solutions of Xanthan gum and caster sugar, and stabilised with a non-ionic food grade surfactant (PGE 55). Rheological measurements were conducted inside a parallel plate geometry on a controlled stress/strain rheometer. The effects of foam microstructural properties as defined by the process parameters (rotor speed, foam air fraction) and liquid composition (Xanthan gum concentration) are elucidated. Simultaneous in-situ visualisation of the foam during shearing revealed for the first time the existence of inward shear-induced radial migration of liquid at high shear rates which is responsible for the time-dependence behaviour of the foams. The foam flow curves were successfully fitted to a generalised dimensionless form of the Carreau-Yasuda model with data for all conditions investigated collapsing approximately on one single curve, which allows prediction of foam apparent viscosity as a function of air volume fraction.

尽管工业应用范围广泛，但由粘性非牛顿流体产生的泡沫在文献中并未引起足够的重视。我们研究了连续多转子-定子中试规模装置中产生的湿泡沫的稳态剪切流和粘弹性。泡沫由黄原胶和细砂糖的水溶液组成的粘性假塑性液体产生，并用非离子食品级表面活性剂（PGE 55）稳定。在平行板几何形状内在受控应力/应变流变仪上进行流变学测量。阐明了由工艺参数（转子速度，泡沫空气分数）和液体成分（黄原胶浓度）定义的泡沫微结构性能的影响。泡沫在剪切期间的同时原位可视化首次揭示了在高剪切速率下向内剪切诱导的液体径向迁移的存在，这导致了泡沫的时间依赖性行为。泡沫流动曲线已成功地拟合到Carreau-Yasuda模型的广义无量纲形式，其中所研究的所有条件的数据大约在一条曲线上折叠，从而可以预测泡沫表观粘度随空气体积分数的变化。