基于起跳初速度分布的沙颗粒浓度廓线的数值模拟  

A Numerical Simulation of Sand Particle Concentration Profiles Based on the Distribution of the Initial Lift-off Velocity

作　　者：黄新成[1] 刘博[1] 王旭峰[1] 熊英[2] 

机构地区：[1]塔里木大学机械电气化工程学院,新疆阿拉尔843300 [2]塔里木大学现代农业工程重点实验室,新疆阿拉尔843300

出　　处：《中国沙漠》2015年第3期534-541,共8页Journal of Desert Research

基　　金：国家自然科学基金主任基金项目(11242013);国家自然科学基金地区基金项目(11162017)

摘　　要：跃移层内沙颗粒浓度分布是风沙两相流相互作用的结果,准确的沙颗粒浓度分布有助于弄清风沙互馈机制及沙颗粒间相互作用机制。由于沙颗粒浓度分布与沙颗粒起跳初速度分布以及气流运动密切相关,本文基于特定的沙颗粒起跳初速度分布函数,通过构建的沙颗粒在气流中运动的物理模型,并利用四阶精度的Adams-Bashforth-Moulton方法对所构建运动模型进行求解,统计分析稳定状态下两相流中沙颗粒运动轨迹的分布,分析其浓度廓线的垂向分布规律。计算结果表明跃移层内沙颗粒浓度分布廓线与高程呈负指数或伽马分布关系;高度一定时沙颗粒浓度廓线随摩阻风速的增大而减小,随颗粒直径的增大而增大。The sand particle concentration profile of wind blown sand in the saltation layer results from the interaction between wind and sand particles,and precise sand particle concentration profile can help to clarify the feed-back mechanism of wind-sand interactions and interactions between sand particles.Based on a special distribution function of sand particles' initial lift-off velocity and a physical model for the sand particles that moving in the wind flow,the trajectories of sand particles that in the steady state wind-sand flow are numerically calculated by fourth order Adams-Bashforth-Moulton method,and the sand particle concentration profiles are analyzed.The results indicate that the sand particle concentration profiles are directly and closely relevant with wind velocity and sand particle diameters and are exponentially or Gamma distributed with height.Interestingly,it will increase with the increase of the sand particle diameter and decrease with the increase of the shear velocity at any particular height.

关 键 词：起跳初速度 沙颗粒浓度廓线 四阶精度的Adams-Bashforth-Moulton方法 数值模拟 

分 类 号：P931.3[天文地球—自然地理学]