气液固三相湍流流动的E/E/L模型与模拟

采用基于双流体模型与粒子分散模型相结合的方法 ,建立了一个用于描述气液固三相湍流流动的Eulerian/Eulerian/Lagrangian模型 (简称E/E/L模型 ) .在Euler坐标系中考虑了气液两相 ,利用双流体模型来表述气液两相的相互关系 ;同时在Lagrange坐标系中考察了颗粒的运动 ,并把颗粒对气液两相的影响耦合于双流体模型中 .以流化床内气液固三相湍流流动为例进行的数值模拟结果与实验结果吻合良好 .所提出的模型及其模拟具有很好的准确性和可靠性 ,为研究气液固三相湍流流动提供了一种新的途径     

溶血磷脂的制备及其性能研究

溶血磷脂可通过磷脂酶Ａ_２的催化而获得。酶浓度、钙离子浓度、温度和ｐＨ对溶血磷脂转化率都有影响．对溶血磷脂性能的研究表明,溶血磷脂的乳化能力、乳化液在高温和低温下、在不同ｐＨ条件下的稳定性都明显高于普通磷脂,并且具有较强的广谱抗菌能力．     

溶血磷脂的制备及其性能研究

溶血磷脂可通过磷脂酶A2的催化而获得。酶浓度,钙离子浓度,温度和pH对溶血磷脂转化率都有影响,对溶血磷脂性能的研究表明,溶血磷脂的乳化能力,乳化液在高温和低温下,在不同pH条件下的稳定性都明显高于普通磷脂,并且具有较强的广谱抗菌能力。     

塔板液相三维流场的研究(Ⅰ)试验测量

本文针对热膜流速仪元件的工作原理提出了在平面旋转测量液体三维流速的方法,并测量了大型精馏塔板液相单相三维流场。为计算流体力学对塔板模拟提供了实验验证。测量结果发现在塔板的回流区、出口堰和塔壁附近流速的垂直分量是不可忽略的,有的地方流速的垂直分量的大小与其水平分量数量级相同。     

气-液-固三相下喷环流反应器局部气相流动特性

The local gas-phase flow characteristics such as local gas holdup (εg), local bubble velocity (Vb) and local bubble mean diameter (db) at a specified point in a gas-liquid-solid three-phase reversed flow jet loop reactor was experimentally investigated by a five-point conductivity probe. The effects of gas jet flow rate, liquid jet flow rate, solid loading, nozzle diameter and axial position on the local εg, Vb and db profiles were discussed. The presence of solids at low solid concentrations not only increased the local εg and Vb, but also decreased the local db. The optimum solid loading for the maximum local εg and Vb together with the minimum local db was 0.16 × 10-3 m3, corresponding to a solid volume fraction, εS = 2.5%.     

Wavelet Transform of Velocity-Time Data for the Analysis of Turbulent Structures in a Trayed Bubble Column

Hydrodynamic and turbulent structures in the trayed bubble column with 1.2m inner diameter have been characterized from liquid-phase velocity-time series data obtained by the hot-film anemometer. Wavelet transform analysis was used for denoising the measured data and also for evaluating quantifiers of turbulence, viz., local intermittency measure, intermittency index and flatness factor. These quantifiers help in detecting the passage of bubbles and reveal the hidden structures and patterns in data. Also, the wavelet scalewise analysis of the turbulence     

通过速度-时间数据的小波变换研究筛板式鼓泡塔中的湍流结构

Hydrodynamic and turbulent structures in the trayed bubble column with 1.2m inner diameter have been characterized from liquid-phase velocity-time series data obtained by the hot-film anemometer. Wavelet transform analysis was used for denoising the measured data and also for evaluating quantifiers of turbulence, viz., local intermittency measure, intermittency index and flatness factor. These quantifiers help in detecting the passage of bubbles and reveal the hidden structures and patterns in data. Also, the wavelet scalewise analysis of the turbulence at various locations in the column and under different operating conditions could be used to build a direct relationship between the local gas holdup and flatness factor. The methodology is therefore suitable for online evaluation of the trayed bubble column performance and shows promise for developing strategies for improving process performance.     

塔板液相三维流场的研究(Ⅱ)CFD模拟

本文应用计算体力学软件STAR—CDV3．1求解了1．2m直径光板的三维流速场分布，文中应用K-ε模型封闭雷诺方程，构成二方程模型。计算过程中，采用了压力修正法中的SIMPLE算法，贴体网格及局部加密技术。理论计算与光板上热膜风速仪的实测结果吻合较好，这表明了前文提出的一种基于理论的测量塔板三维流场的新方法是合理的。