Effect of bubble volume fraction on the shear and extensional rheology of bubbly liquids based on guar gum (a Giesekus fluid) as continuous phase
Effect of bubble volume fraction on the shear and extensional rheology of bubbly liquids based on guar gum (a Giesekus fluid) as continuous phase
复制标题
气泡体积分数对基于瓜尔胶（Giesekus 流体）作为连续相的气泡液体的剪切和拉伸流变学的影响
DOI：
10.1016/j.jfoodeng.2014.09.012
复制
发表时间：
2015
影响因子：
5.5
通讯作者：
D. Wilson
中科院分区：
文献类型：
--
作者：
M. Torres;B. Hallmark;D. Wilson
研究了气泡体积分数 phi 对瓜尔胶水溶液稳定剪切和拉伸流变学的影响，在 0 ⩽phi⩽ 0.25 和胶浓度 (i) 5 g/L 和 (ii) 10 g/L 下，对应于 (i) 半稀释和 (ii) 缠结状态下的溶液。流体的流变响应在很大程度上与气泡尺寸无关，但强烈依赖于 。粘性和弹性模量随着气泡体积分数的增加而增加，在较高的胶浓度下弹性占主导地位。使用细丝拉伸进行研究的拉伸流变测定表明，液丝的细化动力学受到气泡尺寸的影响，但细丝断裂时间主要取决于 。剪切和拉伸的流变行为可以建模为单模式 Giesekus 流体，使用一组参数能够描述半稀释状态下的剪切和拉伸行为。在纠缠态中，单模 Giesekus 流体可以单独拟合剪切数据或拉伸数据，但不能同时拟合两者。拟合的 Giesekus 流体模型参数表现出对 phi 的强烈依赖性，提供了一种预测这些复杂食品流体的流动行为的方法。
The effect of air bubble volume fraction,ϕ, on the steady shear and extensional rheology of aqueous guar gum solutions was studied at 0 ⩽ϕ⩽ 0.25 and gum concentrations of (i) 5 g/L and (ii) 10 g/L, corresponding to solutions in the (i) semi-dilute and (ii) entanglement regime. The rheological response of the fluids was largely independent of bubble size but strongly dependent onϕ. The viscous and elastic moduli increased with increasing bubble volume fraction, with elastic dominance prevalent at the higher gum concentration. Extensional rheometry, investigated using filament stretching, revealed that the thinning dynamics of the liquid thread were affected by bubble size, but the filament rupture time was primarily dependent onϕ. The rheological behaviour in both shear and extension could be modelled as a single mode Giesekus fluid, with a single set of parameters able to describe both the shear and extensional behaviour in the semi-dilute regime. In the entanglement regime the single mode Giesekus fluid could fit the shear data or the extensional data individually, but not both. The fitted Giesekus fluid model parameters exhibited a strong dependency onϕ, offering a way to predict the flow behaviour of these complex food fluids.