CAJ | 학술논문

　　针对沙尘的扩散问题开展了沙粒点源扩散风洞实验，结果显示沙粒经点源扩散后质量沿高度的分布服从高斯分布，这与已有点源扩散研究结果一致。随着风速的变化，沙粒垂向扩散的中心高度随风速的平方呈反比，均方差随风速呈反比；随着与点源距离的增加，中心高度呈线性减小，均方差呈线性增加。同时，根据实验结果给出了点源扩散分布质量沿高度分布的中心高度和均方差随风速、粒径和扩散距离的表征方程。此外，分析结果还表明混合沙粒扩散后不同高度处的平均粒径随高度呈线性递减，这与已有的野外沙尘暴期间的粉尘粒径观测结果是一致的。
　　침대사진적확산문제개전료사립점원확산풍동실험，결과현시사립경점원확산후질량연고도적분포복종고사분포，저여이유점원확산연구결과일치。수착풍속적변화，사립수향확산적중심고도수풍속적평방정반비，균방차수풍속정반비；수착여점원거리적증가，중심고도정선성감소，균방차정선성증가。동시，근거실험결과급출료점원확산분포질량연고도분포적중심고도화균방차수풍속、립경화확산거리적표정방정。차외，분석결과환표명혼합사립확산후불동고도처적평균립경수고도정선성체감，저여이유적야외사진폭기간적분진립경관측결과시일치적。
The motion of particles, such as dispersion of dust and volcanic ash, in the atmosphere can lead to various environmental problems and endanger our daily life. In the paper, a dispersion experiment of mixed sand particles from a point source in wind tunnel was performed to enhance our understanding of the dynamics of sand particles in the atmosphere. The results revealed that the mass distribution of dispersed particles from the source point followed the Gaussian law at the vertical direction, which is consistent with previous studies. The Gauss mean value of dispersed particles was inversely proportional to the square of the friction speed, but decreased linearly with the distance of the dispersion downwind being away from the source point. In contrast, the mean square deviation was inversely proportional to the friction speed, and increased linearly with the distance of dispersion. Based on the experimental results, both the Gauss mean value and the mean square deviation were related to wind velocity, the averaged diameter of particles and the distance of dispersion, and explicit expressions were obtained correspondingly. Furthermore, the averaged diameter of dispersed particles along height at the vertical direction was analyzed and the results showed the averaged diameter decreased linearly with the height, which is in accordance with the observed results in the field during dust storms.