论文标题
基于大涡模拟的耦合湍流风波的表征
Characterization of Coupled Turbulent Wind-wave Flows Based on Large Eddy Simulation
论文作者
论文摘要
风波相互作用涉及在波面上的风力强迫和对湍流风结构的波浪影响,这基本上影响了风和波载在结构上。现有关于风波相互作用建模的研究忽略了风的固有强湍流。本研究旨在表征波动表面上的湍流和在风驱动力下的波动动力学。开发了高保真两相模型,以模拟高度湍流的风波场。使用湍流斑点方法在入口边界处方规定了固有的风湍流,而不是使用均匀的风。通过将模拟的风波流量特性与实验数据进行比较,可以验证开发的模型。通过经过验证的模型,在极端风和波浪条件下以10^2 m的比例进行数值案例研究。结果表明,当考虑固有的风湍流时,将增强结果湍流,是固有湍流和波诱导的湍流的总和。另外,由于风固有的湍流的存在,波浪相干速度和避难所效应得到了增强。强烈的湍流区域取决于风速和波相速度之间的相对速度。较高的风速会导致更大的湍流强度,可将其增加高达17%。风与波之间的不同相对速度可以诱导波相干速度的相反的正阴模式。波量速度与风速大致成正比,受影响的区域主要取决于波高。
Wind-wave interaction involves wind forcing on wave surface and wave effects on the turbulent wind structures, which essentially influences the wind and wave loading on structures. Existing research on wind-wave interaction modeling ignores the inherent strong turbulences of wind. The present study aims to characterize the turbulent airflow over wave surfaces and wave dynamics under wind driving force. A high-fidelity two-phase model is developed to simulate highly turbulent wind-wave fields. Instead of using uniform wind, inherent wind turbulences are prescribed at the inlet boundary using the turbulent spot method. The developed model is validated by comparing the simulated wind-wave flow characteristics with experimental data. With the validated model, a numerical case study is conducted on a 10^2 m scale under extreme wind and wave conditions. The result shows that when inherent wind turbulences are considered, the resultant turbulence is strengthened and is the summation of the inherent turbulence and the wave-induced turbulence. In addition, the wave coherent velocities and shelter effect are enhanced because of the presence of wind inherent turbulence. The regions of intense turbulence depend on the relative speed between wind velocity and wave phase speed. Higher wind velocities induce greater turbulence intensities, which can be increased by up to 17%. The different relative speed between wind and wave can induce opposite positive-negative patterns of wave coherent velocities. The wave-coherent velocity is approximately proportional to the wind velocity, and the influenced region mainly depends on the wave heights.