共查询到19条相似文献,搜索用时 187 毫秒
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对三层搅拌桨气-液两相搅拌反应器内的流体流动进行了实验研究,用Pro-E软件建立模型,利用计算流体动力学(CFD)方法对反应器内部整体气含率、局部气含率、流场流体分布及变化规律进行数值模拟计算。研究了在通入气体的条件下,桨叶搅拌速率对整体气含量的影响。结果表明,组合桨的结构对于气液流场分布特性有着关键的影响。 相似文献
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针对面向性能的发动机冷却风扇叶片几何形状优化的问题,将参数化建模技术应用到对冷却风扇叶片安装角的描述中,建立了冷却风扇的参数化模型,以多学科优化平台Isight和商业流体模拟软件Fluent为基础,建立了一种模型参数化、网格划分、CFD分析和多目标优化相结合的发动机冷却风扇优化集成平台,并运用非支配排序遗传算法对冷却风扇进行了优化。对优化结果与试验结果进行了对比,分析了冷却风扇的内部流场。研究结果表明,优化后的风扇模型静压提高了12.840 6%,动压和风扇效率也有所提高,冷却风扇的整体性能得到了优化。 相似文献
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旋转射流搅拌器全场数值模拟分析 总被引:2,自引:0,他引:2
目前应用于大型工程流体储罐最安全、最有效的搅拌系统是旋转射流搅拌(RJM)系统.在RJM系统的设计开发过程中,工业上对该系统的要求是不仅要射程远,能够使储罐流体横向有运动,而且要求四周的扩散效果要更好.针对以高粘度流体为工作介质,采用标准k-ε湍流模型,对储罐内射流搅拌的全三维流场进行了数值模拟计算,估算了射流的流程、影响范围及搅拌效果,采用数值计算方法考察了搅拌效果.研究结果显示,该方法可以克服实验中经费投入和测量精度等方面的限制,对工程应用具有很重要的意义. 相似文献
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污水处理搅拌机的水力设计与试验研究 总被引:1,自引:0,他引:1
针对目前国内污水处理搅拌池内流场测试研究空白,为研究污水处理搅拌机性能,选用NACA翼型,应用升力法对污水处理搅拌机叶片进行水力设计,并对搅拌池内流体流场分布进行试验研究。在设计的试验台上,利用流速仪,通过空间布点测量了污水搅拌池内不同位置的流体速度。利用EXCEL软件绘制了污水处理搅拌池内不同位置截面上的流体速度分布图,分析了池内流体速度分布规律。流体速度沿着轴向传递明显,流体径向扩散相对较小,且污水搅拌池内流体的流速基本沿污水处理搅拌机轴对称分布。试验表明:该测量方法可行,且该污水处理搅拌机具有明显的轴向导流和减少池壁边界对池内流体的影响作用。 相似文献
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Mathematical model and experiment validation of fluid torque by shear stress under influence of fluid temperature in hydro-viscous clutch 总被引:1,自引:0,他引:1
The current design of hydro-viscous clutch(HVC) in tracked vehicle fan transmission mainly focuses on high-speed and high power. However, the fluid torque under the influence of fluid temperature can not be predicted accurately by conventional mathematical model or experimental research. In order to validate the fluid torque of HVC by taking the viscosity-temperature characteristic of fluid into account, the test rig is designed. The outlet oil temperature is measured and fitted with different rotation speed, oil film thickness, oil flow rate, and inlet oil temperature. Meanwhile, the film torque can be obtained. Based on Navier-Stokes equations and the continuity equation, the mathematical model of fluid torque is proposed in cylindrical coordinate. Iterative method is employed to solve the equations. The radial and tangential speed distribution, radial pressure distribution and theoretical flow rate are determined and analyzed. The models of equivalent radius and fluid torque of friction pairs are introduced. The experimental and theoretical results indicate that tangential speed distribution is mainly determined by the relative rotating speed between the friction plate and the separator disc. However, the radial speed distribution and pressure distribution are dominated by pressure difference at the lower rotating speed. The oil film fills the clearance and the film torque increases with increasing rotating speed. However, when the speed reaches a certain value, the centrifugal force will play an important role on the fluid distribution. The pressure is negative at the outer radius when inlet flow rate is less than theoretical flow, so the film starts to shrink which decreases the film torque sharply. The theoretical fluid torque has good agreement with the experimental data. This research proposes a new fluid torque mathematical model which may predict the film torque under the influence of temperature more accurately. 相似文献
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Tae-An Kim D. -W. Kim S. -K. Park Youn J. Kim 《Journal of Mechanical Science and Technology》2008,22(10):1876-1882
A cross-flow fan having forward curved blades relatively produces higher dynamic pressure at low rotating speed because a
working fluid passes through an impeller blade twice. Most of this dynamic pressure is transferred to the static pressure
in a rearguider and a stabilizer as a scroll in the centrifugal fan. The effect of a rearguider and a stabilizer on the performance
of a cross-flow fan is higher than that of the impeller. Therefore, it should be considered how the shape of a rearguider
and an exit duct affects on the performance and the flow fields. The purpose of this study is to investigate the reciprocal
relation to the flow field and performance among the design parameters. Two-dimensional, unsteady governing equations are
solved using FVM algorithm, sliding grid system and standard k - ɛ turbulence model. Verlocity profiles with various parameters are depicted. Furthermore, the meridional velocity profiles
around the impeller are plotted at fixed rotating speed and design flow rate.
This paper was presented at the 9th Asian International Conference on Fluid Machinery (AICFM9), Jeju, Korea, October 16–19, 2007. 相似文献
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