不那么平滑的弹性流中的间歇性
Rahul K Singh1, Prasad Perlekar2, Dhrubaditya Mitra3
1Complex Fluids and Flows Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
Nature communications
|May 27, 2024
概括
弹性流,一个低雷诺兹数现象,与牛顿流有相似之处. 直接模拟揭示了权力规律能量光谱和间歇性的证据,挑战了以前的假设.
科学领域:
- 流体动力学 流体动力学
- 聚合物物理 聚合物物理
- 非牛顿式的流动.
背景情况:
- 弹性流源于低雷诺兹数的粘弹性流体中的弹性不稳定性.
- 经典流在牛顿流体中是很好的理解,但它与弹性流的关系不太清楚.
研究的目的:
- 用直接的数值模拟来研究弹性流的特征.
- 将弹性流与牛顿流进行比较.
- 为了确定电力规律光谱和弹性流中间歇性的证据.
主要方法:
- 粘弹性流体流量的直接数值模拟.
- 动能和聚合物能光谱的分析.
- 一个规模的能源预算计算.
- 速度差异的结构函数分析.
- 从能量消散率计算多分形光谱.
主要成果:
- 确定了动能 (E(k) ~ k^-4) 和聚合能 (Ep(k) ~ k^-3/2 的功率定律光谱,独立于德博拉数.
- 在动量方程中证明了粘性和聚合物项之间的平衡.
- 观察到速度差异中的非微不足道的次导贡献,表明间歇性.
- 结构功能和能量消耗率提供了多元化的证据.
结论:
- 弹性流与牛顿流的相似之处比之前所认为的更多.
- 这些发现支持弹性流的间歇性和多重性质.
- 直接的数值模拟是有效的阐明复杂的流现象在粘弹性流.
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