在动能量级联模型中对极端波动进行即时重要抽样
Guilherme Tegoni Goedert1, Luca Biferale2
1School for Applied Mathematics, Getúlio Vargas Foundation, Praia de Botafogo, 190, Rio de Janeiro, Rio de Janeiro, 22250-900, Brazil. guilherme.goedert@fgv.br.
The European physical journal. E, Soft matter
|December 21, 2023
概括
途径积分方法在流体模型中有效地采样极端事件. 虽然对于简单的案例有效,但在外模型中,准确性随着非线性强度的增加而下降.
科学领域:
- 流模拟的流模型.
- 计算流体动力学 计算流体动力学
- 统计物理学的统计物理.
背景情况:
- 失去平衡的流量表现出非高斯波动的可观测值,如能量消耗率.
- 极端波动虽然很少见,但在物理系统中具有显著的现象学.
- 来自量子场理论的路径积分方法越来越多地应用于流体动力学.
研究的目的:
- 探索基于实例的重要性采样对流的外模型的适用性.
- 通过不同程度的非线性来评估方法的性能.
- 为了评估在流式能量级联中采样极端事件的效率.
主要方法:
- 利用一个外模型,一个动态系统的乱的能量级联.
- 采用基于实例的重要性抽样,路径积分方法.
- 根据热方程极限验证了方法.
- 研究的性能与不断增加的非线性系数.
主要成果:
- 实时方法在弱非线性方面显示出良好的定性协议.
- 在估计分布平面度的准确性随着非线性强度的增加而下降.
- 贝模型允许对极端事件进行高效的数值采样.
结论:
- 基于瞬间的重要性采样是研究流系统中极端事件的一个有前途的技术.
- 该方法的准确性对非线性相互作用的强度敏感.
- 需要进一步的研究来完善强烈非线性制度的方法.
相关概念视频
Maxwell-Boltzmann Distribution: Problem Solving
1.5K
Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v).
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
1.5K
Pressure Variation in a Fluid at Rest
256
In a fluid at rest, the pressure at any point beneath the fluid surface depends solely on the depth, not on the container's shape or size. This principle, known as hydrostatic pressure, arises because, in stationary fluids, there is no acceleration, meaning the forces within the fluid balance out. Only vertical forces, caused by the weight of the fluid above, contribute to pressure changes with depth.
When measuring pressure at two different levels within the fluid, the difference in...
When measuring pressure at two different levels within the fluid, the difference in...
256
Entropy Change in Reversible Processes
2.5K
In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
2.5K
Equilibrium Conditions for a Particle
1.2K
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
1.2K
Turbulent Flow
193
Turbulent flow is characterized by unpredictable fluctuations in velocity and pressure, which result in a chaotic fluid movement distinct from the orderly patterns of laminar flow. While laminar flow is governed by smooth, parallel layers with minimal mixing, turbulent flow exhibits highly irregular, three-dimensional patterns. This behavior arises due to instabilities in the fluid's velocity profile, and amplifies as the flow velocity increases. Minor disturbances, known as turbulent...
193
Entropy
30.2K
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
30.2K


