测量颗粒物质静止角方法研究

Methods of Measuring Angle of Repose for Particulate Matter

根据刘建宝、於海明、董玉秀和周向玲等对不同颗粒物质采用测定静止角的不同方法分析对比,指出其测定颗粒物质静止角的不同方法和适用范围。通过对比得出:直接观测量角器法测定堆积角存在直接观测、操作简便的优点,但是测量结果系统误差较大;自由下落形成颗粒堆积的测量方法有2种,都存在由于颗粒物质积落体成堆积椎体过程中因冲击导致的锥顶秃顶和因惯性导致的锥底非斜直,对沙漠沙静止角的测量存在显著的系统误差,导致实际的测定数值不等于静止角的真实值;刘建宝等利用相似形二次测量进行误差修正的测量方法繁琐,且存在一定的误差。周向玲等人利用沙堆堆积过程录像后转为图像处理求堆积静止角的方法,不需要多次测量底面半径和高度,直接减少了系统误差带来的影响,此方法的适用范围广,并可以同时定多个静止角,降低了实验的复杂度和重复数,便于快速测得物质的静止角值且精确度较高。

According to the different methods used by LIU Jian-bao,YU Hai-ming,DONG Yu-xiu and ZHOU Xiang-ling,et al,to measure an angle of repose for different particulate matter,we measured the angle of repose and analyzed their advantages and disadvantages,and provided a reference for the fu-ture research of particulate matter repose angle.By comparsion,it is shown that there is a direct observa-tion for the direct observation accumulation angle protractor method,and it is an advantage of simple op-eration,but the measurement result is poorer in the system error.There are two kinds of measuring method in accumulation of particles form the free fall.Because of product fall into granular material in the process of vertebral bodies due to the impact caused by the cone top a bald head and the cone bottom of the inclined straight as a result of inertia,there is a remarkable system error in measurement of desert sand re-pose angle.The actual measured value is not equal to the angle of repose of real value.LIU Jian-bao,et al,used the measurement method of similar-type secondary measurement error correction,which is tedi-ous,and there are still some errors.ZHOU Xiang-ling,et al,used the sand accumulation process after the video into image processing for accumulation method of angle of repose,which do not need any meas-urement base radius R and height H,and reduces the effects directly from the system error.This method is of a wide scope of application,which can also determine multiple angle of repose reduce the complexity of the experiment and the repeat number.Thus it is rapid to measure the value for repose angle of material with higher accuracy.