摘要
本文按照两个相似流动体系必须被同一个物理方程所描述的原理,由水流连续方程的比尺关系导出变态模型的质量守恒误差公式。采用矩阵特征值分析的方法,得到三维流时均流场紊动应力的特征值,并给出了它与模型变率的关系式,由它可分析一维总流分析中的紊动应力相似误差。从概率统计的角度利用实验资料给出泥沙沉降公式,并可与服从Gauss分布的概率公式联解计算出泥沙沉降分布,亦可用于泥沙沉降相似的经验公式λω=uλ(λL/hλ)m中指数m的分析与计算。对目前常用的两种泥沙起动相似的经验公式进行分析,并比较了二者的相对误差。
As we know, the model test should have model with similar geometry and the relevant physical dimensionless parameters should be in dynamical similarity. However, it is almost impossible to make the river model completely similar to the prototype and it is so called as distorted model. This paper presents the analysis of the errors caused by that reasons. Based on the fundamental equations of fluid dynamics following topics have been investigated： （1） the error of mass conservation in continuity equation, （2） the error of similarity of turbulent stress in 3-Dtime-meanvelocity field, （3） the value of the exponent m in sedimentation formula λω=λu （λL/2h ）^m and the error of the predicted sedimentation velocity, and （4） the relative error of two kinds formula, which are usually used for predicting the inception of sedimentation at present.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2005年第5期565-570,共6页
Chinese Journal of Hydrodynamics
关键词
变态模型
相似理论
精度与误差
distorted model
similarity theory
accuracy ＆ error
