The influence of the non-Newtonian properties of blood on the flow in large arteries:: unsteady flow in a 90° curved tube
The influence of the non-Newtonian properties of blood on the flow in large arteries:: unsteady flow in a 90° curved tube
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DOI：
10.1016/s0021-9290(99)00014-7
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发表时间：
1999-07-01
影响因子：
2.4
通讯作者：
Janssen, JD
中科院分区：
文献类型：
--
作者：
Gijsen, FJH;Allanic, E;Janssen, JD
对 90 度弯管中的不稳定入口流进行了数值和实验研究，以研究血液的非牛顿特性对速度分布的影响。牛顿和非牛顿血液模拟流体的时间依赖性流速是相同的。在数值计算中，采用 Carreau-Yasuda 模型来适应黄原胶溶液的剪切稀化行为。没有考虑粘弹性。实验结果表明牛顿流体和非牛顿流体之间存在显着差异。牛顿流体和非牛顿流体的数值结果与实验结果非常吻合。由于粘弹性未包含在数值代码中，因此即使在不稳定流动条件下，血液模拟流体的剪切稀化行为似乎也是主要的非牛顿特性。最后，对非牛顿流体模型和牛顿流体在重新调整的雷诺数下进行了比较。重新调整的雷诺数是基于黄原胶溶液的特性而不是高剪切速率粘度，大约是原始雷诺数的三倍。比较表明，采用合适的雷诺数可以很好地模拟非牛顿流体的特性。 (C) 1999 Elsevier Science Ltd. 保留所有权利。
A numerical and experimental investigation of unsteady entry flow in a 90 degrees curved tube is presented to study the impact of the non-Newtonian properties of blood on the velocity distribution. The time-dependent flow rate for the Newtonian and the non-Newtonian blood analog fluid were identical. For the numerical computation, a Carreau-Yasuda model was employed to accommodate the shear thinning behavior of the Xanthan gum solution. The viscoelastic properties were not taken into account.The experimental results indicate that significant differences between the Newtonian and non-Newtonian fluid are present. The numerical results for both the Newtonian and the non-Newtonian fluid agree well with the experimental results. Since viscoelasticity was not included in the numerical code, shear thinning behavior of the blood analog fluid seems to be the dominant non-Newtonian property, even under unsteady flow conditions.Finally, a comparison between the non-Newtonian fluid model and a Newtonian fluid at a rescaled Reynolds number is presented. The rescaled Reynolds number, based on a characteristic rather than the high-shear rate viscosity of the Xanthan gum solution, was about three times as low as the original Reynolds number. Comparison reveals that the character of how of the non-Newtonian fluid is simulated quite well by using the appropriate Reynolds number. (C) 1999 Elsevier Science Ltd. All rights reserved.