基于微米沙尘高温弹塑性碰撞理论及沙尘-壁面碰撞沉积模型和两相流理论,研究了不同温度下1~5μm沙尘与镍基单晶材料壁面碰撞沉积特性,分析了气流流动特性、颗粒运动轨迹和碰撞沉积结果等,研究了粒径和温度对微米沙尘碰撞率、沉积率和捕...基于微米沙尘高温弹塑性碰撞理论及沙尘-壁面碰撞沉积模型和两相流理论,研究了不同温度下1~5μm沙尘与镍基单晶材料壁面碰撞沉积特性,分析了气流流动特性、颗粒运动轨迹和碰撞沉积结果等,研究了粒径和温度对微米沙尘碰撞率、沉积率和捕捉率的影响。结果表明:微米沙尘在通道输送过程中不同出口位置处运动轨迹差异较大;温度为1323 K时,直径1~5μm沙尘碰撞率随粒径减小而减小,1μm沙尘沉积率和捕捉率最大,分别为37.86%和6.049%,2μm以上沙尘沉积率和捕捉率相对较小;直径1μm沙尘在1273,1323和1343 K 3种温度下沉积率和捕捉率随温度升高而增大。展开更多
To research a novel technology for dry coarse coal slime beneficiation and extend its application, active pulsing air separation technology was investigated by DEM-CFD coupling simulation approach. The results show th...To research a novel technology for dry coarse coal slime beneficiation and extend its application, active pulsing air separation technology was investigated by DEM-CFD coupling simulation approach. The results show that the ash content of feed is reduced by 10% 15% and the organic efficiency is up to 91.78% by using the active pulsing air separation technology. The gas solid flow in the active pulsing air classifier was simulated. Meanwhile, the characteristics of particle motion and the separation process of different particles were analyzed, and the mechanical structure of the classifier was also modified to achieve high separation efficiency. Therefore, a novel high-efficiency dry beneficiation technique was advanced for coarse coal slime.展开更多
Turbulence enhancement by particle wake effect is studied by numerical simulation of gas turbulent flows passing over particle under various particle sizes, inlet gas velocities, gas viscosity, gas density and the dis...Turbulence enhancement by particle wake effect is studied by numerical simulation of gas turbulent flows passing over particle under various particle sizes, inlet gas velocities, gas viscosity, gas density and the distance of particles. By performing dimension analysis and using the form of gas-particle interaction source term for reference, a new semi-empirical turbulence enhancement model by the particle-wake effect is proposed. The turbulence model is then incorporated into second-order moment model for simulating gas-particle flows in a horizontal channel with different wall roughness and a sudden-expansion chamber. The results show that this model is with higher calculating accuracy than another two turbulence models in comparison with the experimental results.展开更多
文摘基于微米沙尘高温弹塑性碰撞理论及沙尘-壁面碰撞沉积模型和两相流理论,研究了不同温度下1~5μm沙尘与镍基单晶材料壁面碰撞沉积特性,分析了气流流动特性、颗粒运动轨迹和碰撞沉积结果等,研究了粒径和温度对微米沙尘碰撞率、沉积率和捕捉率的影响。结果表明:微米沙尘在通道输送过程中不同出口位置处运动轨迹差异较大;温度为1323 K时,直径1~5μm沙尘碰撞率随粒径减小而减小,1μm沙尘沉积率和捕捉率最大,分别为37.86%和6.049%,2μm以上沙尘沉积率和捕捉率相对较小;直径1μm沙尘在1273,1323和1343 K 3种温度下沉积率和捕捉率随温度升高而增大。
基金Projects(51221462,51134022,51074156)supported by the National Natural Science Foundation of ChinaProject(2012CB214904)supported by the National Basic Research Program of ChinaProject(20120095130001)supported by Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘To research a novel technology for dry coarse coal slime beneficiation and extend its application, active pulsing air separation technology was investigated by DEM-CFD coupling simulation approach. The results show that the ash content of feed is reduced by 10% 15% and the organic efficiency is up to 91.78% by using the active pulsing air separation technology. The gas solid flow in the active pulsing air classifier was simulated. Meanwhile, the characteristics of particle motion and the separation process of different particles were analyzed, and the mechanical structure of the classifier was also modified to achieve high separation efficiency. Therefore, a novel high-efficiency dry beneficiation technique was advanced for coarse coal slime.
基金the National Natural Science Foundation of China(No.50736006)the Aero-Science Fund(No.2009ZB56004)the Jiangxi Provincial Natural Science Foundation(Nos.2009GZC0100 and 2008GZW0016)
文摘Turbulence enhancement by particle wake effect is studied by numerical simulation of gas turbulent flows passing over particle under various particle sizes, inlet gas velocities, gas viscosity, gas density and the distance of particles. By performing dimension analysis and using the form of gas-particle interaction source term for reference, a new semi-empirical turbulence enhancement model by the particle-wake effect is proposed. The turbulence model is then incorporated into second-order moment model for simulating gas-particle flows in a horizontal channel with different wall roughness and a sudden-expansion chamber. The results show that this model is with higher calculating accuracy than another two turbulence models in comparison with the experimental results.
