【摘要】 通过对不同粒径、不同湿度的赤泥起尘风速及起尘强度的风洞实验发现,对各种湿度的赤泥,都存在一临界粒径。当赤泥粒径小于该值时,起尘风速随粒径的减小而增大,而当粒径大于该值时,起尘风速随粒径的增大而增大。临界粒径大约为0.2mm,随湿度略有变化。临界粒径对应的起尘风速最小,它随湿度的增大而升高,其变化范围为2.5～3.0m/5,对应的起动摩擦速度介于0.17～0.20m/s。此外,当粒径小于0.1mm时,起尘风速随湿度的增大而减小,而当粒径大于0.2mm 以后,起尘风速随湿度的增大而增大。起尘强度实验表明,风速一定且大于4.7m/s,湿度小于15%时,起尘强度随湿度增大而减小,湿度大于15%时,起尘强度随湿度变化甚微。风速小于4.7m/s时,起尘强度基本不随湿度而变。湿度一定时,起尘强度随风速的增大而增大。文章还讨论了模拟实验的相似准则和定量换算问题。更多还原

【Abstract】 By wind tunnel experiment for sedimentary material withdifferent size and different humidity,it is found that the drifting speed(at which the particles begin to move)increases as particle size decreaseswhen its diameter is less than some critical diameter,which is around0.2mm,and when the size of particles is larger than that value,thedrifting speed increases with the size of particles increasing.The par-ticles with critical diameter have the minimum drifting speed around 2.5to 3m/s,corresponding to the friction speed of 0.17—0.20 m/s.Theyare the same as those Iversen gave.The larger the humidity,the larger theminimum drifting speed.When the diameter of the particles is less 0.1mm,the drifting speed decreases with humidity increosing,and when it isargerl than 0.2mm,the drifting speed increases with humidity increosing.The experiment also indicates that under steady wind speed largerthan 4.7m/s,the mass rate of the sedimentary material decreases withhumidity when the humidity is less than 15%, but when it is larger than15%, the deposit rate has little variation. When the wind speed is lessthan 4.7m/s,the deposit rate is almost not variant with humidity.Under constant humidity,the deposit rate increases with wind speed.It seems to follow the power law.The simulation criteria are also discussed.The experiment indicatesthat the full scale material is appropriate as modeling particles,butthe care must be taken for transformation of modeling results into thefull scale ones.更多还原