Asymptotes of maximum friction and heat transfer reductions for drag-reducing surfactant solutions
Asymptotes of maximum friction and heat transfer reductions for drag-reducing surfactant solutions
复制标题
减阻表面活性剂溶液的最大摩擦和传热减少的渐近线
DOI：
10.1016/s0017-9310(00)00319-7
复制
发表时间：
2001
影响因子：
5.2
通讯作者：
E. Matthys
中科院分区：
文献类型：
--
作者：
G. Aguilar;K. Gasljevic;E. Matthys
提出了一种新的表面活性剂溶液最大减阻渐近线。使用包括阳离子和非离子表面活性剂溶液的各种浓度来实验确定该渐近线。结果表明，如果溶剂粘度用于计算雷诺数和普朗特数的粘性解决方案，它会导致低估的摩擦系数。为了避免流体粘度选择中的不确定性，有意调节使用的大多数溶液，使其剪切粘度在所涵盖的范围内与水相似。使用相同的解决方案，最大传热减少渐近线（MHTRA）也被确定-一个相关性，不存在的表面活性剂，直到现在。最后，通过使用稍微修改的定义来量化传热和阻力减少（TRH和TRD），可以用1.06的恒定值来表示MHTRA和MHTRA之间的比率，与雷诺数无关。当剪切粘度存在不确定性时，该关系可用作确定解是否渐近的辅助判据。
A new maximum drag reduction asymptote (MDRA) for surfactant solutions is presented. Various concentrations including cationic and non-ionic surfactant solutions were used to experimentally determine this asymptote. It is shown that if solvent viscosity is used to compute Reynolds and Prandtl numbers for viscous solutions, it leads to underestimations of the friction coefficient. To avoid uncertainties in the selection of the fluids viscosity, most solutions used were intentionally conditioned so their shear viscosity was water-like in the ranges covered. Using the same solutions, a maximum heat transfer reduction asymptote (MHTRA) was also determined – a correlation that did not exist for surfactants until now. Finally, by using slightly modified definitions to quantify the heat transfer and drag reductions (TRH and TRD), it is possible to express the ratio between the MHTRA and MDRA with a constant value of 1.06, independent of Reynolds number. This relationship can be used as an auxiliary criterion to determine whether or not a solution is asymptotic when there is an uncertainty about the shear viscosity.