排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
用Level Set方法求解具有自由面的流动问题 总被引:9,自引:0,他引:9
为采用Level Set方法来计算有自由的流动问题提出了一种方案,把自由水面视为水和空气的交界面,两种介质用统一的N-S方法求解,在自由面两侧分别采用各自的密度和粘性,并在自由面上给以适当的光滑;采用边界元法求解双调和方程来确定距离函数;N-S方程用投影法求解,文中给出了二维水池水面振荡和瞬时溃坝问题的算例,可以看出用LevelSet方法求解有自由面流动问题是有效的。 相似文献
2.
采用光滑粒子动力学SPH(Smoothed Particle Hydrodynamics)方法对三维溃坝流问题进行了数值模拟。为了逼真地模拟出坝内水体与壁面间相互作用而产生的水花飞溅、融合以及近壁面流动等现象,加入了混合长度形式的湍流模型。为了有效地防止粒子穿透固壁,提出了一种新型的适合三维数值模拟的固壁边界处理方法。应用SPH方法对三维溃坝流进行了数值模拟,并分别考虑了未添加障碍物和添加圆柱障碍物两种情形。计算结果表明,改进SPH方法能够精细地捕捉溃坝流在不同时刻的自由液面,并获得稳定而精确的数值结果。 相似文献
3.
4.
The central problem of the lattice Boltzmann method (LBM) is to construct a discrete equilibrium. In this paper, a multi-speed 1D cell-model of Boltzmann equation is proposed, in which the cell-population equilibrium, a direct non- negative approximation to the continuous Maxwellian distribution, plays an important part. By applying the explicit one-order Chapman-Enskog distribution, the model reduces the transportation and collision, two basic evolution steps in LBM, to the transportation of the non-equilibrium distribution. Furthermore, 1D dam-break problem is performed and the numerical results agree well with the analytic solutions. 相似文献
5.
针对下游带有障碍物的溃坝流动问题,本文基于两相流动模型,在有限元算法框架下对其进行数值模拟研究。依据水平集(Level Set)方法追踪运动界面,并引入了一个简单的修正技术,保证较好的质量守恒性。为了精确表示运动界面,采用稳定和有效的间断有限元方法求解双曲型Level Set及其重新初始化方程。对于两相统一Navier-Stokes方程,首先利用分裂格式对其解耦,然后通过SUPG (Streamline Upwind Petrov Galerkin)方法进行数值求解。模拟研究了下游带有障碍物的牛顿流体溃坝流动问题,得到的数值结果与文献已有模拟结果及实验结果均吻合较好。此外,还考虑了幂律型非牛顿流体,并分析了不同特性非牛顿流体对于溃坝流动过程和界面形态等的影响。 相似文献
6.
A. V. Chebotnikov 《Journal of Applied Mechanics and Technical Physics》2009,50(3):441-446
This paper gives experimental data on the propagation speed and height of a dam-break wave arising in the tailwater region
during a partial dam break event. These data were used to confirm the Khristianovich calculation method.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 97–103, May–June, 2009. 相似文献
7.
F. Golay M. Ersoy L. Yushchenko D. Sous 《International Journal of Computational Fluid Dynamics》2015,29(1):67-81
In this work, we present a fast and parallel finite volume scheme on unstructured meshes applied to complex fluid flow. The mathematical model is based on a three-dimensional compressible low Mach two-phase flows model, combined with a linearised ‘artificial pressure’ law. This hyperbolic system of conservation laws allows an explicit scheme, improved by a block-based adaptive mesh refinement scheme. Following a previous one-dimensional work, the useful numerical density of entropy production is used as mesh refinement criterion. Moreover, the computational time is preserved using a local time-stepping method. Finally, we show through several test cases the efficiency of the present scheme on two- and three-dimensional dam-break problems over an obstacle. 相似文献
8.
V. I. Bukreev V. V. Degtyarev A. V. Chebotnikov 《Journal of Applied Mechanics and Technical Physics》2008,49(1):53-57
The paper presents experimental data on the discharge and energy-loss coefficients for two weirs of polygonal profiles with
lateral contraction, which are required, in particular, in simulations of partial dam-break waves. It is shown that the values
of these coefficients for a trapezoidal weir with a slope ratio of 1: 3 differ insignificantly from their values for a rectangular
weir.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 1, pp. 68–73, January–February, 2008. 相似文献
9.
V. I. Bukreev V. V. Degtyarev A. V. Chebotnikov 《Journal of Applied Mechanics and Technical Physics》2008,49(5):754-761
This paper presents results of an experimental study of waves generated by partial break of two model dams. The previously
proposed calculation methods are extended and compared with the experimental data obtained. It is shown that the wave propagation
speed in the tailwater is significantly influenced by the energy losses due to flow through the breach.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 61–69, September–October, 2008 相似文献
10.
移动粒子半隐式法(Moving Particle Semi-implicit,MPS)是一种广泛应用于不可压缩自由表面流动的粒子方法。本文通过把非牛顿流体转化为变黏度牛顿流体的处理方法将MPS方法拓展至非牛顿自由表面流动,以Casson流体和Cross流体为例计算了非牛顿流体的二维溃坝问题。将计算结果与前人数据进行了对比,结果吻合较好。同时对比了非牛顿流体与牛顿流体的计算结果,发现非牛顿流体的溃坝前端发展速度较慢。 相似文献