The current experimental study investigates the rheological characterization of Carbopol gel solutions into a pipe flow using in situ visualization. The shear rate and shear stress profiles for different pressure-driven values are presented and correlated to obtain new steady-state flow curves compared with rheometrical data performed with cross-hatched parallel plate (CHPP) and smooth concentric cylindrical (SCC) geometries at a rotational rheometer. The rheological behavior for the test performed by the in situ visualization was well fitted by the generalized Herschel-Bulkley model, and different values for the coefficient of consistency (K), flow behavior index (n), and yield stress (τ₀) were fitted for the three gel solutions due to the presence of wall slip behavior. The discrepancies between the values of the rheological parameters suggest that conventional rheometrical measurements, which avoid the slippage of the fluid, lead to an overestimation of these parameters, and as a consequence, these discrepancies are extended to the dimensionless numbers calculated for the hydrodynamic flow description. Also, the experimental plug core velocity was compared with the analytical value obtained by the rotational rheometer tests to calculate an equivalent slip velocity, and such velocity depicts a quasi-linear trend with the wall shear stress. This is supported by the apparent viscosity profiles along the pipe diameter, suggesting that the slippage is an inherent characteristic of polymer gel solutions, and it is disseminated by the presence of layers near the pipe wall where the Newtonian like-behavior is presented. Finally, applying in situ visualization technique assures a better rheological characterization and accurate description of the flow conditions for fluids with complex behavior.

当前的实验研究使用原位可视化调查 Carbopol 凝胶溶液在管道流中的流变特性。展示了不同压力驱动值的剪切速率和剪切应力曲线，并将其相关联以获得新的稳态流动曲线，并与旋转平行板 (CHPP) 和光滑同心圆柱 (SCC) 几何结构执行的流变数据进行比较流变仪。原位可视化测试的流变行为与广义 Herschel-Bulkley 模型以及一致性系数 ( K )、流动行为指数 ( n ) 和屈服应力 ( τ _{0 ) 的不同值非常吻合}) 由于存在壁滑行为，因此适用于三种凝胶溶液。流变参数值之间的差异表明，避免流体滑移的常规流变测量导致对这些参数的高估，因此，这些差异扩展到为流体动力流动描述计算的无量纲数. 此外，将实验塞芯速度与通过旋转流变仪测试获得的分析值进行比较，以计算等效滑移速度，并且该速度描绘了与壁面剪切应力的准线性趋势。这得到了沿管道直径的表观粘度分布的支持，表明滑动是聚合物凝胶溶液的固有特征，并且它通过出现牛顿类行为的管壁附近层的存在而传播。最后，应用原位可视化技术确保更好的流变特性和对具有复杂行为的流体的流动条件的准确描述。