摘要
本文以单颗粒为体系和以固相的拟流体微团为体系分别对泥沙运动进行了受力分析,给出了体系的力平衡方程,并证明了两种方程是相容的。通过对比说明,同一个力采用不同的体系分析时分属于不同类型,例如,流体-颗粒间的作用力在前一体系中属于表面力,在后一种体系中属于彻体力;拟流体分析中的表面力(应力),在单颗粒体系的力平衡中根本不出现等等,由此清楚地表明进行受力分析和建立力平衡方程时明确所研究体系的重要性。本文还详细分析了对于上述两种体系,颗粒-颗粒碰撞对体系运动所起的作用,以及在运动方程中的体现,并指出:泥沙运动力学中经常使用的“碰撞力”在概念上是含糊的,计算碰撞力的表达式的根据是可疑的。
Taking a single particle as a system or a pseudo-fluid element of solid phase as a system in research of sediment transport, force analyses, and as a result, force equilibrium equations are presented. It is shown that the two types of equations are compatible. A certain force would classify to different types in different systems. For example, fluid-particle force is a surface force in single particle analysis, but a body force in pseudo-fluid element analysis, however, the surface force (tensor) of the pseudo-fluid model is not present in the force equilibrium equation of single particle model. Therefore, what system is adopted is so important in force analysing that we must remember clearly.The effects of the particle-particle collisions on the system movement and the roles in the force equations are also explained in each system mentioned above, and it is point out that the 'collision force' applied often in studying sediment transport is ambiguous in conception, and the expression computing is doubtful.
出处
《泥沙研究》
CSCD
北大核心
1993年第2期41-47,共7页
Journal of Sediment Research
基金
国家自然科学基金
