不同粒度级配的硼基粉末燃料装填特性和流动性

Loading Characteristics and Flowability of Boron-based Powder Fuels with Different Particle Size Gradations

为了阐明粒度级配对粉末燃料装填特性和流动性的影响规律,提高粉末冲压发动机工作性能,以硼基粉末燃料为对象,研究了颗粒物性和级配方式等对粉末燃料装填特性和流动性的影响,并利用粉末供给系统验证了级配粉末的流化输运性能。结果表明,大粒径颗粒间隙中填充小粒径颗粒能够提升装填密度,但却会降低其流动性;多级级配粉末中的小粒径颗粒流动性较差时,预混装填方式的级配颗粒装填密度高于分批装填方式,反之则分批装填方式更好;团聚造粒制备的硼基粉末燃料粒度分布均有分形分布特征,分形级配的方式也可以提高颗粒装填密度,提升幅度约15.7%,分形级配后分形维数为2.33,装填密度为0.957g/cm^(3),装填率为53.8%,并保持较好的流化性能。

To reveal the effect of particle size gradation on the loading characteristics and flowability of powder fuels and improve the working performance of powder ramjet engines,the effects of particle properties and grading methods on the loading characteristics and flowability of powder fuels were investigated taking boron-based powder fuels as research object.And the fluidized transport performance of the graded powder was verified by powder supply system.The results show that the filling of small-size particles in the gap of large-size particles can improve the filling density but reduce the flowability.When the small-size particles in the multi-stage graded powder are less flowable,the filling density of premixed graded particles is higher than that of batch filling method,and vice versa.The particle size distribution of boron-based powder fuel prepared by agglomerated granulation has the characteristics of fractal distribution.The fractal gradation method can also increase the particle filling density by about 15.7%,the fractal dimension after fractal grading is 2.33,filling density is 0.957g/cm^(3) and filling rate is 53.8%,maintaining good fluidization performance.