Coclite A, Gonnella G, Lamura A
Dipartimento di Meccanica, Matematica e Management, Politecnico di Bari, Via Re David 200, 70126 Bari, Italy.
Dipartimento di Fisica, Università di Bari, and INFN, Sezione di Bari, Via Amendola 173, 70126 Bari, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jun;89(6):063303. doi: 10.1103/PhysRevE.89.063303. Epub 2014 Jun 9.
In this paper the phase behavior and pattern formation in a sheared nonideal fluid under a periodic potential is studied. An isothermal two-dimensional formulation of a lattice Boltzmann scheme for a liquid-vapor system with the van der Waals equation of state is presented and validated. Shear is applied by moving walls and the periodic potential varies along the flow direction. A region of the parameter space, where in the absence of flow a striped phase with oscillating density is stable, will be considered. At low shear rates the periodic patterns are preserved and slightly distorted by the flow. At high shear rates the striped phase loses its stability and traveling waves on the interface between the liquid and vapor regions are observed. These waves spread over the whole system with wavelength only depending on the length of the system. Velocity field patterns, characterized by a single vortex, will also be shown.
本文研究了在周期性势场作用下剪切非理想流体中的相行为和图案形成。提出并验证了一种基于范德瓦尔斯状态方程的液-气系统等温二维格子玻尔兹曼格式。通过移动壁面施加剪切力，周期性势场沿流动方向变化。将考虑参数空间中的一个区域，在无流动情况下，具有振荡密度的条纹相是稳定的。在低剪切速率下，周期性图案得以保留，并因流动而略有扭曲。在高剪切速率下，条纹相失去稳定性，在液-气区域界面上观察到行波。这些波在整个系统中传播，波长仅取决于系统的长度。还将展示以单个涡旋为特征的速度场图案。
