振动和气流协同作用下颗粒物质流变特性研究

项目名称： 振动和气流协同作用下颗粒物质流变特性研究

项目编号： No.51506006

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 刘传平

作者单位： 北京科技大学

项目金额： 20万元

中文摘要： 在现代工农业中，很多原料都以颗粒的形式参与生产，人们往往希望颗粒可以像流体一样可以自由流动方便运输和处理。本申请引入外部能量（机械振动、气流）改善颗粒物料的流动性，研究颗粒物质流变特性以定量预测其流动行为，为流量控制和计量提供方法。颗粒物质本构关系尤其本构关系中屈服应力是影响颗粒流动性（类固或类液态，是否堵塞）的关键，建立颗粒物质本构模型并分析振动参数、气流速度对屈服应力的影响，研究振动和气流对改善颗粒物质流动的等效性、差异性和协同性；同时，根据振动机械能、气流压力能在颗粒物质中的传递和耗散规律，构建向颗粒系统输入能量与颗粒自身流动形态/当量粘度的关系；将颗粒物质视为热力系统，建立系统能量方程和熵方程，并基于热力学理论对其流动形态进行判定，揭示颗粒流动的热力学机理。

中文关键词： 颗粒流；流变特性；振动流化床；非平衡热力学

英文摘要： In modern industry and agriculture, great many raw materials are produced in form of particles. It is expected that the particles can be transported and processed freely as fluid. In this proposal, the external energy (mechanical vibrating and gas blowing from bed bottom) is introduced into granular bed to improve its fluidity, and the rheological properties of the granular material are researched, which can be used to predict particle dynamic characters and provide the method of particle flux controlling and measuring. The constitutive relation, especially the yield stress in this constitutive relation, is the key for influencing the flowability of granular material (solid-like state or liquid-like state, flowing or jamming). After the constitutive relation is established, the effects of the vibration parameters and gas velocity on constitutive relation are analyzed; and then the equivalence, the difference and the cooperation between vibration and gas flow are following researched. Meanwhile, By analyzing the energy transfer and dissipation of the mechanical vibration and the gas flow, the relation function between the introduced energy flux and the granular flow patterns/the equivalent viscosity of the granular flow are also addressed. In addition, the energy and entropy equation of the granular flow are established, and the granular flow is analyzed as a thermodynamic system. Based on the thermodynamic theory, the divide of flow patterns is certified in theory and the granular flowing mechanism would be further revealed.

英文关键词： Granular flow;Rheological property;Vibro-fluidized bed;Non-equilibruim thermodynamics