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Rushton桨搅拌槽中气液两相流动的全流场数值模拟   总被引:9,自引:0,他引:9       下载免费PDF全文
The gas-liquid flow field in a stirred tank with a Rushton disk turbine,including the impeller region,was numerically simulated using the improved inner-outer iterative procedure.The characteristic features of the strirred tank,such as gas cavity and accumulation of gas at the two sides of wall baffles,can be captured by the simulation.The simulated results agree well with available experimental data.Since the improved inner-outer iterative algorithm demands no empirical formula and experimental data for the impeller region,and the approach seems generally applicable for simulating gas-liquid stirred tanks.  相似文献
2.
用改进的内外迭代法数值模拟Rushton涡轮搅拌槽流场   总被引:7,自引:2,他引:5       下载免费PDF全文
在有挡板的搅拌槽中,受搅拌桨驱动的液体在挡板的作用下会产生复杂的三维湍流流动.利用“快照”法思路和改进的内外迭代法及k–e湍流模型对Rushton涡轮有挡板的搅拌槽进行了整体数值模拟. 同文献中的实验数据进行了比较,模拟值同实验值基本吻合. 改进后的内外迭代法不依赖经验公式和实验数据,有一定的通用性.  相似文献
3.
孙海燕  王卫京  毛在砂 《化工学报》2002,53(11):1153-1159
根据搅拌槽内的流动呈各向异性的特点 ,引入适用于强旋转流场的各向异性k -ε湍流模型 ,用改进的内外迭代法对有挡板的Rushton桨搅拌槽进行了整体数值模拟 .利用文献中对搅拌槽内流场测定结果 ,给出了适用于Rushton桨搅拌槽的各向异性湍流黏度系数值 .模拟计算得到了搅拌槽内的流场分布和脉动速度分布 ,并同标准k -ε湍流模型计算结果及文献数据进行比较 .结果表明 ,各向异性k -ε湍流模型能成功反映Reynolds应力、湍流动能等湍流特征量 ,明显优于标准k -ε湍流模型 .  相似文献
4.
In accordance to the anisotropic feature of turbulent flow, an anisotropic algebraic stress model is adopted to predict the turbulent flow field and turbulent characteristics generated by a Rushton disc turbine with the improved inner-outer iterative procedure. The predicted turbulent flow is compared with experimental data and the simulation by the standard κ-ε turbulence model. The anisotropic algebraic stress model is found to give better prediction than the standard κ-ε turbulence model. The predicted turbulent flow field is in accordance to experimental data and the trend of the turbulence intensity can be effectively reflected in the simulation. The distribution of turbulent shear rate in the stirred tanks was simulated with the established numerical procedure.  相似文献
5.
根据搅拌槽内的流动呈各向异性的特点,引入适用于强旋转流场的各向异性k-ε湍流模型,用改进的内外迭代法对有挡板的Rushton桨搅拌槽进行了整体数值模拟.利用文献中对搅拌槽内流场测定结果,给出了适用于Rushton 桨搅拌槽的各向异性湍流黏度系数值.模拟计算得到了搅拌槽内的流场分布和脉动速度分布,并同标准k-e湍流模型计算结果及文献数据进行比较.结果表明,各向异性k-ε湍流模型能成功反映Reynolds应力、湍流动能等湍流特征量,明显优于标准k-ε湍流模型.  相似文献
6.
动态混合絮凝器内絮团浓度分布的研究   总被引:1,自引:1,他引:0  
实验测定了平直叶轮动态混合絮凝器内絮团浓度的空间分布。结果表明,沿絮凝器半径方向,絮团浓度先是随半径的增大而增大,在达到某一最大值后则转而降低;在絮凝器的轴向,絮团浓度在叶轮上方附近存在极大值,在上下两侧,则逐渐降低;但在器壁附近,絮团浓度的轴向分布有所不同。文中运用沉降-扩散理论,结合絮凝器内的流体动力条件,对上述现象进行了合理解释。  相似文献
7.
范茏     王卫京     杨超     毛在砂 《中国化学工程学报》2004,12(3):324-329
Stirred tanks are used extensively in process industry and one of the most commonly used impellers in stirred tanks is the R.ushton disk turbine. Surprisingly few data are available regarding flow and mixing in stirred-tank reactors with Rushton turbine in the laminar regime, in particular the laminar flow in baffled tanks.In this paper, the laminar flow field in a baffled tank stirred by a standard R.ushton turbine is simulated with the improved inner-outer iterative method. The non-inertial coordinate system is used for the impeller region, which is in turn used as the boundary conditions for iteration. It is found that the simulation results are in good agreement with previous experiments. In addition, the flow number and impeller power number calculated from the simulated flow field are in satisfactory agreement with experimental data. This numerical method allows prediction of flow structure requiring no experimental data as the boundary conditions and has the potential of being used to scale-up and design of related process equipment.  相似文献
8.
Three-dimensional solid-liquid flow is mathematically formulated by means of the “two-fluid” approach and the two-phase k-ε-Ap turbulence model. The turbulent fluctuation correlations appearing in the Reynolds time averaged governing equations are fully incorporated. The solid-liquid flow field and solid concentration distribution in baffled stirred tanks with a standard Rushton impeller are numerically simulated using an improved “inner-outer” iterative procedure. The flow pattern is identified via the velocity vector plots and a recirculation loop with higher solid concentration is observed in the central vicinity beneath the impeller. Comparison of the simulation with experimental data on the mean velocities and the turbulence quantities of the solid phase is made and quite reasonable agreement is obtained except for the impeller swept volume. The counterpart of liquid phase is presented as well. The predicted solid concentration distribution for three experimental cases with the average solid concentration up to 20% is also found to agree reasonably with the experimental results published in the literature.  相似文献
9.
实验测定了平直叶轮动态混合絮凝器内絮团粒度的空间分布。结果表明,沿絮凝器半径方向,絮团粒度先是随半径的增大而增大,在达到某一最大值后则转而降低;在絮凝器的轴向,絮团粒度在叶轮上下两侧附近存在极大值。文中分别依据颗粒的离心沉降与径向流动理论以及流体剪切理论解释了絮团粒度的径向分布,从微涡旋理论定性说明了絮团的轴向分布。  相似文献
10.
Three-dimensional solid-liquid flow is mathematically formulated by means of the "two-fluid" approach and the two-phase k-ε-Ap turbulence model. The turbulent fluctuation correlations appearing in the Reynolds time averaged governing equations are fully incorporated. The solid-liquid flow field and solid concentration distribution in baffled stirred tanks with a standard Rushton impeller are numerically simulated using an improved "inner-outer" iterative procedure. The flow pattern is identified via the velocity vector plots and a recirculation loop with higher solid concentration is observed in the central vicinity beneath the impeller. Comparison of  相似文献
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