摘要
采用颗粒流体动力学方法,在考虑沙粒与床面碰撞、沙粒-沙粒的空中碰撞及沙粒与气流的耦合作用后,对自然沙组成的风沙流发生、发展及达到动态稳定的这一个过程进行了数值模拟。数值模拟结果表明,该模型能够实现自然界风沙运动的沙粒蠕移、跃移的基本特征,如风沙流达到稳定的持续时间、输沙率、入射/溅射速度分布、入射/溅射角度分布等,且都与实验结果吻合。同时,在模拟中还发现,沙粒-沙粒在床面以上运动时的碰撞是不容忽视的,当摩阻风速为0.23 m/s,沙粒当量直径为0.228 mm时,其碰撞次数可占总碰撞次数21.5%。
In this paper granular flow dynamics model is proposed to mathematically describe the evolution process of wind-blown sand movement. In this theoretical model, the complex phenomenon is composed of the basic mechanics process, such as particle-bed collision, particle-particle collision and the coupling interaction between saltating particles and wind flow, etc. After numerical calculations of a large system including 72 000 particles, the developing process of natural wind-blown sand movement was successfully realized, which proves that this model can simulate the essential properties of natural sand saltation, such as the duration time （wind-blown sand movement reaches equilibrium state）, the profile of mass flux and distribution of ejected angle, are in good agreement with experimental results. The percentage of the particle-particle collisions increases from the beginning of the developing process of wind-blown sand movement until reaching dynamic equilibrium and accounts for about 21.5% of all the collision times.
出处
《自然灾害学报》
CSCD
北大核心
2013年第2期130-135,共6页
Journal of Natural Disasters
基金
河南省重点学科资助项目(504906)
河南理工大学博士基金资助项目(B2009-84)
关键词
颗粒流体动力学模型
风沙流
碰撞
沙粒-气流耦合
granular flow dynamics model
wind-blown sand flow
collision
coupling of sahating sands and wind flow
