APU故障智能诊断系统设计

针对高旋环境下测试困难、测量精度低这一问题,提出了一种能在高旋环境下实现轴向减速装置,以达到稳定的良好的测试环境。该装置通过驱动仓内大量程陀螺仪测得的转速反馈给控制系统,控制系统输出控制信号来控制伺服电机,同时电机捷联内筒仓,使其相对外部转动方向反向旋转,实现轴向减速。实验结果表明,该装置可在高旋弹药飞行过程中提供稳定测试环境,从而得到更精准的姿态解算结果,为高旋环境下的测试提供了新的思路,具有广阔的应用前景。     

考虑地基-结构-散粒体相互作用时贮仓结构的静、动力研究[Ⅱ]--有限元分析

对贮仓结构的静、动力问题进行了系统的分析计算：考虑到地基—结构—散粒体间的相互作用，引入新的计算模式，对不同地基上的贮仓结构模型进行了系统的有限元静、动力分析计算，并与作者所完成的试验结果进行了比较。结果表明，所提出的计算模式及有限元计算模型是正确的。     

The Reclaim Screw in Mammoth Silos Operating on a Free Surface: Comparison Between Horizontal and Inclined Operation on Free Flowing Bulk Solids

Although the screw conveyor, operating on a free surface, has been used for years as reclaim and storage equipment in mammoth silos, there is no documented knowledge about its spill characteristics. Research at Delft University of Technology together with ESI Eurosilo B.V. on the inclined use of the reclaim screw to achieve homogenization in mammoth silos made this lack of knowledge apparent. This paper presents the results of experiments to gain insight into the spill during reclaiming. Experiments were conducted reclaiming a horizontal surface and up‐ and downwards along an inclined surface, using a free‐flowing bulk material. A relationship was found between the theoretical and effective fill ratio. This relationship shows a certain maximum effective fill ratio and a dependence on the reclaim‐depth. As expected, the effective fill ratio drops quickly when reclaiming upwards, mostly due to flow‐ and throwback: the fill is spilled behind the screw blades and over the axis. Unexpectedly, the effective fill ratio also decreases when reclaiming downwards due to a shift of material towards the non‐reclaiming side where it is left behind forming ridges on the surface. It is expected that all three mechanisms will cause less spill when reclaiming a cohesive material. The experiments provide the desired insight into spill mechanisms during reclaiming. Indeed, the inclined use of the reclaim screw to achieve homogenization is thought feasible when reclaiming downwards.     

颗粒物质中的奇异现象

通过分析颗粒物质中一些有别于气体、液体和固体的奇异现象,结合生活和生产中的实际例子进一步认识颗粒物质的一些基本特性、规律、有待解决的问题及研究意义.     

粮仓效应的圆盘堆积模型

为研究圆筒中颗粒堆内部的应力分布，将颗粒堆简化为规则的二维圆盘堆积模型．对圆盘堆积中力的传递进行分析后给出了圆盘堆积中力的传递规律，利用计算机模拟了圆盘对容器底部的压力，发现底部压力随圆盘层数增加会达到饱和，并将二维圆盘堆积的规律推广到三维颗粒堆，从理论上推导出容器底部平均压强p^-与颗粒填充高度Z的关系．     

Improvements in Silo Design for Moist and Cohesive Bulk Solids by Using a Silo Centrifuge

The Jenike‐method is state of the art in silo design for trouble‐free flow, even for cohesive bulk solids. However, for some bulk solids, especially very cohesive and moist bulk solids, even the correct application of the Jenike‐method can lead to an over‐design of the silo outlet. If a reliable estimation of the critical outlet dimension is possible the dimension as well as the machinery costs can be reduced. Model testing can help to reduce the over‐design but reasonable test equipment and flexibility are only possible with silo centrifuge testing. Results, regarding the state of stress and the critical outlet dimensions, from experiments using a silo centrifuge with cohesive and moist bulk solids are presented. The influence of creeping effects on silo design is investigated using the silo centrifuge with moist gypsum.     

筒仓效应观测仪的设计及其应用

设计并制作了观测静态颗粒物质筒仓效应的实验系统,应用该装置研究了筒仓效应的尺寸依赖性.实验结果表明:圆柱形容器中的颗粒物质对于容器底部的饱和压力依赖于容器直径的3次方,而改变填入颗粒的直径时则饱和压力并无明显改变.     

颗粒物质(上)

颗粒物质是地球上存在最多、最为人们所熟悉的物质类型之一．大量颗粒组成的离散态物质体系具有特别的性质和运动规律．颗粒物质表现出许多不同于固、液、气物质的奇特现象和独特的运动规律．由于对颗粒物质运动规律的理解具有重要科学意义和应用背景，近十年来颗粒物质研究逐步成为物理学研究中的一个活跃领域．文章综述了颗粒物质的一些主要特性，如颗粒物质的静态性质、振动行为、流动特性等，其中也包括文章作者的一些新近研究结果．限于篇幅，文章分为上、下两部分发表．第一部分在对颗粒物质作一般介绍后讨论颗粒物质的静态特性，第二部分则主要讨论颗粒物质振动时的行为和流动性质．     

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通过筒仓卸料试验的现象分析，导出最不利情况下的仓壁侧压力计算公式，可供筒仓设计参考．     

煤仓内煤散料流动状态与力学行为影响因素

针对煤仓内煤散料流动问题及其力学行为,采用三维颗粒流模拟程序PFC3D建立了某型号煤仓与某种煤散料的离散元模型,简述了其力学模型与求解步骤,模拟分析了煤仓内煤散料卸料流动状态。通过分析水平向侧压力、颗粒速度场和接触力场,重点讨论了煤仓下部锥体内壁面摩擦系数、锥仓倾角和卸料口径等对煤散料颗粒流动状态和力学行为的影响。结果显示,深仓卸料流动为整体流动与中心流动混合状态,煤仓内壁摩擦系数、锥体倾角和卸料孔开口半径均对煤散料流动和水平侧压力有较大影响。