首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 156 毫秒
1.
旋风分离器减阻杆减阻的数值研究   总被引:5,自引:2,他引:5  
文中首次利用数值方法对旋风分离器进行了减阻杆减阻的研究。应用CFD计算流体力学软件FLUENT,对某种型号的Stairmand高效型旋风分离器的三维有旋流场速度和压力进行了数值模拟,计算了减阻杆的减阻效率。流场和减阻效率的数值结果与实验数据吻合较好,证明对旋风分离器减阻杆减阻研究时所采用的网格划分方法、RSM湍流模型和边界条件是可靠的,为数字设计高效率的减阻杆提供了简便可靠的办法。  相似文献   

2.
为分析旋风除尘器的速度场和分离效率,通过计算流体力学(Computational Fluid Dynamics,CFD)方法研究典型的旋风除尘器的强旋流场.用ANSYS Workbench提供的Geometry和Mesh软件进行三维几何建模和非结构网格划分,以高炉煤气的除尘为例进行流场仿真.湍流模拟采用雷诺应力模型,分离效率预测采用基于拉格朗日方法的离散相模型(Discrete Phase Model,DPM).通过分析压力场和速度场的分布,得到旋风除尘器中的内、外旋流结构;该结构并非完全稳定,涡轴存在一定的摆动.仿真结果表明选用的旋风除尘器模型对高炉煤气有良好的除尘效率.  相似文献   

3.
为了探索新型清晰切割分级方法,本文以Stairmand型旋风分离器为对象进行了窄进料分级性能的模拟与实验研究.模拟软件采用FLUENT6.2,气相流场选用后k-εRealizable模型,颗粒相采用随机轨道模型.实验设备直径0.1 m,进口风速10 m/s,颗粒粒径在0.1 μm~36 μm之间.模拟与实验结果表明:与全进料相比,窄进料能够得到更高的分级效率与更好的分级精度,但提高不大.颗粒轨迹模拟结果表明,这种情况是由旋风分离器本身固有的"短路流"与"下灰环"夹带造成.  相似文献   

4.
A computer solution for subsonic, two-dimentional, gas-particle flows is applied to the study of the flow field in an axial-inlet peripheral-discharge cyclone separator. The analysis shows the effect of gas-particle momentum coupling on the gas flow field and a fractional collection efficiency. The results explain the observed increase in overall collection efficiency with increased dust loading.  相似文献   

5.
阐述了LabVIEW软件的特点、功能,介绍在旋风筒导流板减阻器研究开发中的具体应用.实践证明,采用IabVIEW数据采集分析系统,对试验及研发工作起到较大促进作用.试验研究加设不同形式导流板的旋风器,结果表明:不同形式的导流板减阻器均不同程度地降低了旋风器阻力,同时对分离效率产生相应的影响.其中3号导流板减阻器降阻最大可达40%,其分离效率相对较低;2号的降阻效果优于1号弱于3号,但分离效率基本不变;1号导流板减阻器在一定条件内有减阻效果,其分离效率却比较理想.  相似文献   

6.
颈动脉斑块的形成与复杂的血流动力学因素密切相关,血液流动状况的精确模拟对颈动脉斑块的临床诊断具有重要意义。为了精确模拟脉动流场,在格子Boltzmann方法(LBM)的基础上,添加大涡模拟(LES)模型,建立了LBM-LES颈动脉模拟算法。利用医学图像重构软件,建立颈动脉狭窄真实几何模型,对颈动脉狭窄脉动流动进行了数值模拟,通过计算血液流动速度、壁面剪切应力(WSS)等,得出了有意义的流动结果,验证了LBM-LES对颈动脉狭窄后段血液流动研究的有效性。基于OpenMP编程环境,在高性能集群机全互联胖节点上进行了千万量级网格的并行计算,结果表明LBM-LES颈动脉模拟算法具有较好的并行性能。  相似文献   

7.
The flow field and the acoustic field of a high-lift configuration consisting of a slat and a main wing are numerically investigated by a hybrid method. In a first step, the unsteady flow field is computed via a large-eddy simulation (LES) and in a second step, the acoustic field is determined by solving the acoustic perturbation equations (APE). The mean flow field is compared to experimental findings followed by an investigation of the turbulent structures which are visualized by λ2 contours. The analysis of the acoustic field shows that at the main wing trailing edge acoustic pressure fluctuations of approximately 5 kHz are generated. Correlations between the noise sources and the acoustic pressure identify the slat-gap region to be responsible for the mixture of broadband and tonal noise between 1 and 3 kHz. The decay of the pressure spectrum is found to be approximately f−2 which is in agreement with the literature.  相似文献   

8.
Improving simulation performance using activity tracking has attracted attention in the modeling field in recent years. The reference to activity has been successfully used to predict and promote the simulation performance. Tracking activity, how- ever, uses only the inherent performance information contained in the models. To extend activity prediction in modeling, we propose the activity enhanced modeling with an activity meta-model at the meta-level. The meta-model provides a set of interfaces to model activity in a specific domain. The activity model transformation in subsequence is devised to deal with the simulation difference due to the heterogeneous activity model. Finally, the resource-aware simulation framework is implemented to integrate the activity models in activity-based simulation. The case study shows the improvement brought on by activity-based simulation using discrete event system specification (DEVS).  相似文献   

9.
The effect of sidewall boundary conditions on the computed unsteady flow and sound pressure level is investigated in a transonic open cavity. The hybrid approach used for modeling turbulence combines a Reynolds averaged mode in the boundary layer, and a large eddy simulation mode in the massively separated flow region within the cavity to resolve the wide dynamic range involved. Computational results are presented for the instantaneous vorticity and for the sound pressure level spectra. Comparison of the results obtained using inviscid and periodic sidewall boundary conditions show the sensitivity of the computed SPL spectra and autocorrelation to the conditions enforced at the sidewalls. The computed SPL spectra are also compared with available experimental results, with LES computational results, and with prior investigations based on the same hybrid turbulence model without the wall function used in the current investigation. The comparisons show that the current results obtained using inviscid sidewall boundary conditions are closest to the experimental sound pressure level spectra and that agreement is achieved at considerable saving in required computational resources.  相似文献   

10.
The problem of ash settling on super-heater tube bank, due to improper velocity distribution, in the cyclone separator used at Circulating Fluidized Bed Combustion (CFBC) has been investigated by means of computational fluid dynamic techniques. With the help of Computational Aided Design (CAD) software packages, the geometries of recycling cyclone, has been constructed. With the suitable domain decomposition for the cyclone geometry, multi-block structured mesh has been generated and exported to commercial Computational Fluid Dynamic (CFD) solver – TASCflow. After assembling these grids in the flow solver, duplicate elements at mating surfaces are eliminated through generalized grid interfaces. Incompressible viscous flow for the specified flow conditions are simulated and numerical results are interpreted through contour plots and streak lines. The velocity distribution pattern obtained from the analysis exhibits strong flow recirculation with large turbulent eddies in the cyclone outlet. The analysis also observed high pressure drop across the cyclone separator. To improve the velocity distribution and to reduce the pressure drop, geometry has been modified with the deflector plates in the outlet duct and repeated the simulation. The results obtained for modified geometry are encouraging and shown the improved velocity distribution pattern in the outlet duct. The calculation of particle trajectories depends upon Stokes number, relative velocity of fluid/particles and concentration of particles. If the Stokes number, defined as the ratio of particle response time to system response time is less than one, particles motion is inline with the fluid motion. If the Stokes number is greater than one, particle motion deviates the fluid streams. Effects of these particle impacts are significant on component surface, especially, when they reacts/rebounds the wall surfaces.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号