The experimental viscosity measurement of a certain type of the solid propellant slurry is carried out by using the press bar‐fall ball viscometer. Moreover, the CFD simulation is performed through the ANSYS Fluent software to numerically investigate the press bar‐fall ball viscometer. The viscosity‐time characteristics of the slurry are studied in detail. The present study shows that, when the steel ball falls in the static slurry, the ball is initially accelerated so that its velocity increases. On the other hand, when the ball velocity reaches a certain value, called the terminal velocity, forces are balanced and the velocity remains constant. The medium viscosity is experimentally measured in the present study. Then proper corrective correlations are applied to the Stokes equation to calculate the medium viscosity according to the simulation results. Comparisons show that results of the numerical simulation are in good agreement with the ones from the experiment. It is observed that the viscosity of the slurry rises exponentially with time, due to the curing reaction. Furthermore, since the shear stress of the dropping ball in the solution is small, the shear rate of the solution during the falling of the ball is very low. Therefore, it is concluded that the falling ball method is capable to accurately determine the static viscosity of the slurry.

中文翻译：

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压棒-落球式粘度计测量固体推进剂浆料粘度的实验研究与数值模拟

某种类型的固体推进剂浆料的实验粘度测量是通过使用压杆式落球粘度计进行的。此外，通过ANSYS Fluent软件执行CFD模拟，以对压杆下落球粘度计进行数值研究。详细研究了浆料的黏度-时间特性。本研究表明，当钢球落入静态浆料中时，钢球首先会加速，因此其速度会增加。另一方面，当球速度达到某个值（称为终极速度）时，力将平衡并且速度保持恒定。在本研究中通过实验测量了中等粘度。然后将适当的校正相关性应用于斯托克斯方程，以根据模拟结果计算介质粘度。比较表明，数值模拟结果与实验结果吻合良好。观察到，由于固化反应，浆料的粘度随时间呈指数增加。此外，由于溶液中滴下的球的剪切应力小，所以在球下落时溶液的剪切率非常低。因此，得出的结论是，落球法能够准确确定浆料的静态粘度。由于固化反应。此外，由于溶液中滴下的球的剪切应力小，所以在球下落时溶液的剪切率非常低。因此，得出的结论是，落球法能够准确确定浆料的静态粘度。由于固化反应。此外，由于溶液中滴下的球的剪切应力小，所以在球下落时溶液的剪切率非常低。因此，得出的结论是，落球法能够准确确定浆料的静态粘度。