气固两相射流的数值研究

本文根据ＰＳＩ－Ｃｅｌｌ模型，用差分法计算，分析了喷嘴内的气固两相流动和喷嘴外的自由射流，不计颗粒间的相互作用，粒子自旋，粒子和固壁间的碰撞模型为非规则模型，并将部分计算结果与实验作了比较，吻合良好，计算结果表明在气－固两相射流中，粒径大的粒子比密度小的粒子其轴线速度衰减得慢，而密度的变化却对粒子的扩散快慢影响不大。     

SECOND-ORDER MOMENT TWO-PHASE TURBULENCE MODEL ACCOUNTING FOR TURBULENCE MODULATION IN SWIRLING SUDDEN-EXPANSION CHAMBER

A semi-empirical turbulence enhancement model accounting for the particle-wake effect was incorporated into the second-order moment two-phase turbulence model and employed to simulate gas-particle flows in a swirling sudden-expansion chamber. The simulated results for two-phases mean velocities and fluctuation velocities coincide well with the experiment ones, which demonstrates that this model, in comparison with the turbulence model not accounting for the wake effect, leads to higher calculating accuracy.     

涡旋管内强旋湍流气固两相流的数值模拟

本文建立了基于一种合理考虑湍流-离心力相互作用的新的代数Peynolds应力模型和颗粒随机轨道模型的强旋湍流气固两相流动数学模型。应用该模型对新型涡旋管内的强度湍流气固两相流进行了数值模拟，揭示了涡旋管内气固两相湍流流动的基本特性以及改变切向出口气体流率对流动的影响。     

NUMERICAL SIMULATION OF GAS TURBULENCE ENHANCEMENT BY PARTICLE-WAKE EFFECT

A new turbulence enhancement model was incorporated into the second-order moment two-phase turbulence model and was used to simulate gas-particle flows in swirling chambers and channels with different wall roughness. The results show that compared with the turbulence modification model not accounting for the wake effect,this model,together with the conventional particle source term,gives simulation results in better agreement with the experimental data.     

NUMERICAL STUDY OF PARTICLE DISTRIBUTION IN THE WAKE OF GAS-PARTICLE TWO-PHASE FLOWS PAST A CIRCULAR CYLINDER AT HIGH REYNOLDS NUMBER

1. INTRODUCTION Particle ladengasflowspastcircularcylinders areoftenencounteredinindustrial,environmental andenergy relatedprocesses.Becausethegas flowspastcircularcylindersarecharacterizedby thedevelopmentofwakevortices,itwouldsuffice tosaythatunderstandingthemechanismofparti cledistributioninthewakeofcircularcylindersis crucialforreliablepredictions.Thenumericalstudiesofparticledispersioninplanemixinglay ers,planjets,andsprayshavebeenmadeexten sively,anditwasfoundthatthelargeorganized…     

颗粒浓度及颗粒尺寸对管内气固两相流动速度结构的影响

本文应用ＬＤＶ技术对方管内网栅后的气固两相流动，在平均粒么Ｄｐ＝０．３５ｍｍ，颗粒质量浓度为０．１２％，０．２１％，０．３３５％；Ｄｐ＝０．６ｍｍ，颗粒质量质量浓度为０．１６％，０．２４５％，０．３４５％；Ｄｐ＝０．９ｍｍ，颗粒质量浓度为０．２０５％，０．３０％多种工况下进行测量，给出了各种工况下气流时均速度及颗粒时均速度的分布情况。通过与纯气流条件下的实验结果比较分析了颗粒浓度及颗粒尺寸对管内气     

A NEW TURBULENCE MODULATION IN SECOND-ORDER MOMENT TWO-PHASE MODEL AND ITS APPLICATION TO HORIZONTAL CHANNEL

A new second-order moment two- phase turbulence model accounting for particle wake effect was established and used to simulate gas-particle flow in a horizontal channel for different values of wall roughness. The results show that compared with the model without considering the particle wake effect, the present model gives simulation results agreeing much better with the experimental results for the gas turbulence modulation, but the predicted results for particle motion with the two kinds of models are quite close.     

气—固两相流边界层双向耦合模型及其应用

本文提出了一种稀相的气－固两相流边界层的双向耦合模型，在对固壁附近的粒子源项作子特殊处理后，利用此模型研究了流经平面叶栅的气－固两相流中的固体粒子越边界层时受到的影响以及粒子存在对边界层内气体流动的反影响。其中粒子运动特的计算结果与试验进行了对比分析。     

冲动式透平平面叶栅内气－固两相流动的试验研究

本文利用高速摄影和图象处理技术真实地再现了平均粒径ｄｐ＝７００μｍ的固体位子流经冲动式透平平面叶栅的瞬间过程，分析了粒子在叶栅内的运动轨迹及其在叶栅内的浓度和速度分布特性。文中还对沿叶栅表面分布的纯气流压力和气相压力进行了测量。结果表明：粒子的尺寸和初始位置对粒子在叶栅内的运动轨迹有很大影响；在粒子与叶片碰撞比较频繁的部位附近，粒子相互聚集，形成粒子聚集区，在此区域内，粒子的浓度比较高，粒子的速度更为复杂；在粒子聚集区附近，气相压力相对纯气流压力的变化值比较大。     

A TWO-SCALE SECOND-ORDER MOMENT PARTICLE TURBULENCE MODEL FOR GAS-PARTICLE FLOW

NOMENCLATURE U — mean velocity u, v — fluctuation velocity uu, vv — Reynolds stress e ― restitution coefficient d ― particle diameter k —kinetic energy α p— particle volume fraction ρ p — particle density β ― drag coefficient ε —kinetic ener