颗粒堆的体积分数与制备流量关系的实验研究

通过实验研究发现,颗粒堆的体积分数随制备颗粒堆的颗粒流流量指数衰减,减小或增加流量到一定程度时,体积分数都达到饱和;出料口直径与颗粒粒径的比值小到一临界值时,随着流量的减小体积分数增加急剧变缓;颗粒粒径小到一临界值时,随着流量的增加,体积分数的减小急剧变缓.结合颗粒物质的强耗散性、空气作用、瓶颈效应和碰撞理论解释了实验现象,从连续性原理出发推出的颗粒堆体积分数随制备流量变化的函数与实验数据的拟合公式相同.

Experimental studdy on relation between volume fraction of sandpiles and flow rate of forming sandpiles

The function of volume fraction η versus flow rate Q was determined. It is found that η decreases exponentially with increase of Q. The volume fraction η will reach saturation when Q is reduced or increased to certain extent. The increase of η slows down rapidly with decrease of Q when D/d decreases to a critical value. The decrease of η slows rapidly with increase of Q when of decreases to a critical size. The phenomenon is explained by the dissipation of granules, effect of air, effect of bottleneck and collision theory.Theoretical result about η-Q is in agreement with the experimental result.