雷诺兹数缩放和能量光谱在地质对流的对流
Matteo Madonia1, Andrés J Aguirre Guzmán1, Herman J H Clercx1
1Fluids and Flows group, Department of Applied Physics and J. M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Journal of fluid mechanics
|June 16, 2023
概括
研究人员研究了旋转的雷利-贝纳德对流,观察流动力学和速度缩放. 结果表明,随着Ekman数的减少,乱的散装流状态正在接近.
科学领域:
- 流体动力学 流体动力学
- 地质物理学 地质物理学
- 流是什么?流是什么?流是什么?
背景情况:
- 旋转的雷利-贝纳德对流是地球物理流的一个关键模型.
- 了解地层对流需要分析力平衡和流动模式.
研究的目的:
- 为了研究在地质系内旋转雷利-贝纳德对流的流量测量.
- 为了比较速度波动缩放与理论力量平衡 (VAC和CIA).
- 探索向无扩散流状态的过渡.
主要方法:
- 立体粒子图像速度计 (PIV) 用于测量3D速度组件.
- 实验是在一个圆柱形的对流容器中进行的,在一个固定的Ekman数 (Ek) 上,具有不同的雷利数 (Ra).
- 分析了流量数据的速度缩放,动能光谱和力量平衡影响.
主要成果:
- 粘性-阿基米德-科里奥利斯 (VAC) 和科里奥利斯-惯性-阿基米德 (CIA) 两种力平衡都显示出与速度缩放的良好一致.
- 随着Ekman数的减少,观察到向无扩散速度缩放的趋同.
- 动能光谱显示了四极旋结构,以及在更高的Ra时出现-5/3缩放范围的发展,这是3D流的特征.
结论:
- 这项研究提供了证据,证明了在旋转对流中实现完全发达,无扩散的乱散流状态的方法.
- 观察到的流体组织和光谱缩放表明了与地球物理现象相关的复杂动态.
- 进一步的研究是有必要的,以充分阐明这个政权的动荡动态.
相关概念视频
01:10Poiseuille's Law and Reynolds Number
6.7K
Any fluid in a horizontal tube can flow due to pressure differences—fluid flows from high to low pressure. The flow rate (Q) is the ratio of pressure difference and resistance through a horizontal tube. The greater the pressure difference, the higher the flow rate. The flow resistance is expressed as:
6.7K
01:15Dimensionless Groups in Fluid Mechanics
376
Dimensionless groups in fluid mechanics provide simplified ratios that help analyze fluid behavior without relying on specific units. The Reynolds number (Re), which represents the ratio of inertial to viscous forces, distinguishes between laminar and turbulent flows, making it essential in the design of pipelines and aerodynamic surfaces. The Froude number (Fr), the ratio of inertial to gravitational forces, is particularly useful in predicting wave formation and hydraulic jumps in...
376
01:24Reynolds Transport Theorem
1.3K
The Reynolds transport theorem provides a framework to relate the time rate of change of an extensive property within a system to that in a control volume, which is crucial for analyzing fluid dynamics. Extensive properties, such as mass, velocity, acceleration, temperature, and momentum, can be expressed in terms of the mass of a fluid portion. These properties are called extensive because they depend on the system's size, while intensive properties are their corresponding values per unit...
1.3K
01:16Energy Conservation and Bernoulli's Equation
9.0K
Applying the conservation of energy principle or the work-energy theorem to an incompressible, inviscid fluid in laminar, steady, irrotational flow leads to Bernoulli's equation. It states that the sum of the fluid pressure, potential, and kinetic energy per unit volume is constant along a streamline.
All the terms in the equation have the dimension of energy per unit volume. The kinetic energy per unit volume is called the kinetic energy density, and the potential energy per unit volume is...
All the terms in the equation have the dimension of energy per unit volume. The kinetic energy per unit volume is called the kinetic energy density, and the potential energy per unit volume is...
9.0K
01:09The Buckingham Pi Theorem
755
The Buckingham Pi theorem provides a structured method to simplify fluid dynamics problems by reducing complex systems of variables to dimensionless terms.
755
00:59Bernoulli's Equation
10.6K
In the middle of the nineteenth century, it was observed that two trains passing each other at a high relative speed get pulled towards each other. The same occurs when two cars pass each other at a high relative speed. The reason is that the fluid pressure drops in the region where the fluid speeds up. As the air between the trains or the cars increases in speed, its pressure reduces. The pressure on the outer parts of the vehicles is still the atmospheric pressure, while the resultant...
10.6K