de Goede Thijs C, de Bruin Karla G, Bonn Daniel
Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
Netherlands Forensic Institute, Laan van Ypenburg 6, 2497 GB, The Hague, The Netherlands.
Sci Rep. 2019 Feb 4;9(1):1250. doi: 10.1038/s41598-018-37543-1.
We investigate which property of non-Newtonian fluids determines the deceleration of a high-speed impacting object. Using high-speed camera footage, we measure the velocity decrease of a high-speed spherical object impacting a typical Newtonian fluid (water) as a reference and compare it with a shear thickening fluid (cornstarch) and a shear thinning viscoelastic fluid (a weakly cross-linked polymer gel). Three models describing the kinetic energy loss of the object are considered: fluid inertia, shear thickening and viscoelasticity. By fitting the three models to the experimental data, we conclude that the viscoelastic model works best for both the cornstarch and the polymer gel. Since the cornstarch is also viscoelastic, we conclude that the ability to stop objects of these complex fluids is given by their viscoelasticity rather than shear thickening or shear thinning.
我们研究了非牛顿流体的哪种特性决定了高速撞击物体的减速情况。利用高速摄像机拍摄的画面，我们测量了高速球形物体撞击典型牛顿流体（水）时的速度降低情况作为参考，并将其与剪切增稠流体（玉米淀粉）和剪切变稀粘弹性流体（弱交联聚合物凝胶）进行比较。考虑了描述物体动能损失的三个模型：流体惯性、剪切增稠和粘弹性。通过将这三个模型与实验数据进行拟合，我们得出粘弹性模型对玉米淀粉和聚合物凝胶都最为适用。由于玉米淀粉也是粘弹性的，我们得出结论，这些复杂流体阻止物体的能力是由它们的粘弹性而非剪切增稠或剪切变稀决定的。
