Stress in a dilute suspension of spheres in a dilute polymer solution subject to simple shear flow at finite Deborah numbers
Stress in a dilute suspension of spheres in a dilute polymer solution subject to simple shear flow at finite Deborah numbers
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稀聚合物溶液中球体稀悬浮液在有限德博拉数下受到简单剪切流的应力
DOI：
10.1103/physrevfluids.1.013301
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发表时间：
2016
影响因子：
2.7
通讯作者：
Mustafa, Ibrahim
中科院分区：
文献类型：
--
作者：
Koch, Donald L.;Lee, Eric F.;Mustafa, Ibrahim
粒子-聚合物相互作用对系综平均应力的影响是作为一个函数的Deborah数的Oldrophil-B流体中的小聚合物浓度的限制的球的稀悬浮液。随着与颗粒分离，颗粒诱导的聚合物应力的缓慢衰减速率对平均应力的推导提出了挑战，这可以通过在从颗粒诱导的扰动计算体积平均应力之前去除线性化的聚合物应力扰动来克服。线性化应力可以被证明具有零系综平均。聚合物对颗粒的应力波的影响计算与援助的广义互惠定理的基础上经常扰动小聚合物浓度的牛顿流。分析表明，在Sciroccoet等人的实验中观察到了颗粒-聚合物对剪切应力和第一法向应力差的贡献。[填充Boger流体中的剪切增稠，J. Rheol. 49，551（2005）JORHD 20148 -605510.1122/1.1849185]。颗粒-聚合物对第二法向应力差的贡献在小德博拉数时为正，但在德博拉数约为2.3时改变符号。
The influence of particle-polymer interactions on the ensemble average stress is derived as a function of the Deborah number for a dilute suspension of spheres in an Oldroyd-B fluid in the limit of small polymer concentrations. The slow rate of decay of the particle-induced polymer stress with separation from a particle presents a challenge to the derivation of the average stress, which can be overcome by removing the linearized polymer stress disturbance before computing the bulk average stress from the particle-induced disturbance. The linearized stress can be shown to have zero ensemble average. The polymer influence on the particle's stresslet is computed with the aid of a generalized reciprocal theorem based on a regular perturbation from Newtonian flow for small polymer concentration. The analysis shows that the particle-polymer contributions to the shear stress and first normal stress difference shear thicken as has been observed in the experiments of Sciroccoet al.[Shear thickening in filled Boger fluids, J. Rheol. 49, 551 (2005)JORHD20148-605510.1122/1.1849185]. The particle-polymer contribution to the second normal stress difference is positive at small Deborah numbers but changes sign at a Deborah number of about 2.3.