目的使用计算流体力学数值模拟离心血泵内的流场,对计算结果和实验结果进行对比,评估计算方法的可靠性。方法以美国食品药品监督管理局(Food and Drug Administration,FDA)提供的血泵标模进行数值仿真,针对2号工况(转子转速3500 r/min,...目的使用计算流体力学数值模拟离心血泵内的流场,对计算结果和实验结果进行对比,评估计算方法的可靠性。方法以美国食品药品监督管理局(Food and Drug Administration,FDA)提供的血泵标模进行数值仿真,针对2号工况(转子转速3500 r/min,入口体积流量2.5 L/min),分别用SRF旋转参考坐标系方法和滑移网格方法进行定常和非定常流动的数值模拟,将计算结果与FDA通过粒子图像测速法(particle image velocimetry,PIV)获得的流场数据进行比对,探究数据可信度。展开更多
A 3-D numerical simulation with CFX software on physical field of multi-air channel coal burner in rotary kiln was carried out. The effects of various operational and structural parameters on flame feature and tempera...A 3-D numerical simulation with CFX software on physical field of multi-air channel coal burner in rotary kiln was carried out. The effects of various operational and structural parameters on flame feature and temperature distribution were investigated. A thermal measurement was conducted on a rotary kiln (4.5m in diameter, 90m in length) with four-air channel coal burner to determine the boundary conditions and to verify the simulation results. The calculation result shows that the distribution of velocity near burner exit is saddle-like; recirculation zones near nozzle and wall are useful for mixture primary air with coal and high temperature fume. A little central airflow can avoid coal backing up and cool nozzle. Adjusting the ratio of internal airflow to outer airflow is an effective and major means to regulate flame and temperature distribution in sintering region. Large whirlcone angle can intensify disturbution range at flame root to accelerate ignition and mixture. Large coal size can reduce high temperature region and result in coal combusting insufficiently. Too much combustion air will lengthen flame and increase heat loss.展开更多
文摘目的使用计算流体力学数值模拟离心血泵内的流场,对计算结果和实验结果进行对比,评估计算方法的可靠性。方法以美国食品药品监督管理局(Food and Drug Administration,FDA)提供的血泵标模进行数值仿真,针对2号工况(转子转速3500 r/min,入口体积流量2.5 L/min),分别用SRF旋转参考坐标系方法和滑移网格方法进行定常和非定常流动的数值模拟,将计算结果与FDA通过粒子图像测速法(particle image velocimetry,PIV)获得的流场数据进行比对,探究数据可信度。
文摘A 3-D numerical simulation with CFX software on physical field of multi-air channel coal burner in rotary kiln was carried out. The effects of various operational and structural parameters on flame feature and temperature distribution were investigated. A thermal measurement was conducted on a rotary kiln (4.5m in diameter, 90m in length) with four-air channel coal burner to determine the boundary conditions and to verify the simulation results. The calculation result shows that the distribution of velocity near burner exit is saddle-like; recirculation zones near nozzle and wall are useful for mixture primary air with coal and high temperature fume. A little central airflow can avoid coal backing up and cool nozzle. Adjusting the ratio of internal airflow to outer airflow is an effective and major means to regulate flame and temperature distribution in sintering region. Large whirlcone angle can intensify disturbution range at flame root to accelerate ignition and mixture. Large coal size can reduce high temperature region and result in coal combusting insufficiently. Too much combustion air will lengthen flame and increase heat loss.
