相关实验视频
Updated: Jul 5, 2025

07:28
Evolution of Staircase Structures in Diffusive Convection
Published on: September 5, 2018
6.5K
由于热和组成梯度,在对流存在时,正面的不稳定性是由于对流的存在
Roberto Guzman1, Desiderio A Vasquez1,2
1Departamento de Ciencias, Sección Física, Pontificia Universidad Católica del Perú, Av. Univeristaria 1801, San Miguel, Lima 15088, Peru.
Chaos (Woodbury, N.Y.)
|January 19, 2024
概括
无对流反应前线可能由于流体特性和前线动态变得不稳定. 浮力可以增强或稳定这些前线,但随着热梯度出现新的不稳定性,影响前线传播.
科学领域:
- 流体动力学 流体动力学
- 化学反应工程 化学反应工程
- 非线性动力学是一种非线性动力学.
背景情况:
- 反应面将密度差异的流体分离,由热和组成梯度驱动,可能导致对流.
- 平面,无对流面的稳定性受流体特性和前方演变动态的影响.
研究的目的:
- 分析Kuramoto-Sivashinsky (KS) 方程与水力动力学相结合所描述的反应阵线的稳定性和传播.
- 研究浮力和热梯度对前方稳定性和动态的影响.
- 在2D领域数量解决合的非线性KS和纳维尔-斯托克斯方程,用于2D领域的正面传播.
主要方法:
- 库拉莫托-西瓦辛斯基 (KS) 方程与水力学方程相结合的分析.
- 在存在密度梯度和热/组成变化的情况下研究前方稳定性.
- 非线性KS方程的数值模拟与二维矩形域中的纳维埃-斯托克斯方程相结合.
主要成果:
- 没有密度梯度,平坦的KS前线对长波长扰动不稳定.
- 当较低密度的流体低于较密度的流体时,浮力会增加不稳定性;在相反的情况下,稳定性是可能的.
- 在具有足够热梯度的稳定配置中出现了新的不稳定性;对流会导致前部曲率和速度增加.
结论:
- 前方稳定性是流体特性,密度梯度和热/构成效应之间的复杂相互作用.
- 浮力驱动的对流会显著改变反应前端的行为,导致曲率和加速传播.
- 该研究提供了对各种流体配置中的反应前线动态的见解,与涉及合反应扩散和流体流动的现象相关.
相关概念视频
Magnetostatic Boundary Conditions
934
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
934
Conduction, Convection and Radiation: Problem Solving
1.2K
There are three methods by which heat transfer can take place: conduction, convection, and radiation. Each method has unique and interesting characteristics, but all three have two things in common: they transfer heat solely because of a temperature difference; and the greater the temperature difference, the faster the heat transfer.
In order to solve a problem related to heat transfer, first of all, the situation needs to be examined to determine the type of heat transfer involved. This could...
In order to solve a problem related to heat transfer, first of all, the situation needs to be examined to determine the type of heat transfer involved. This could...
1.2K
Static, Stagnation, Dynamic and Total Pressure
377
The concept of static, stagnation, dynamic, and total pressure is fundamental in fluid dynamics, often explained using Bernoulli's equation:
377
Boundary Layer Characteristics
116
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
116
What is Weather?
18.2K
Overview
18.2K
Thermal expansion and Thermal stress: Problem Solving
1.2K
San Francisco's Golden Gate Bridge is exposed to temperatures ranging from -15 °C to 40 °C. At its coldest, the main span of the bridge is 1275 m long. Assuming that the bridge is made entirely of steel, what is the change in its length between these temperatures?
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in...
1.2K

