CAJ | 학술논문

为探索旋流泵内部流场及气液两相流混输特性，该文通过32WB8-12型旋流泵外特性试验和泵最优工况流场五孔探针测量，得出泵性能曲线和5个测点静压ps、绝对速度v、圆周速度vu、径向速度vr和轴向速度vz分布情况。针对N-S方程中四项力在气液两相流动中的具体表现特性进行力学分析，说明了泵内部两相流动特点及关联因素之间约束关系。阐明了旋流泵含气混输抽吸和扬程形成的基本原理，及空化和气液两相流混输的不同特点。选择性能试验最优工况，基于改进重组化群k-ε湍流模型（RNG k-ε模型），应用Fluent软件对泵内部流场进行数值模拟，得到了3个轴面静压、速度矢量和含气率分布图。证明泵进口轴向运动为主流，气体主要集中在压力较低的进口区域。气相的引入，其微团与液相尺寸、形状及弹性模量的不同，造成两相流场惯性力、摩擦力和浮力发生变化，由此解释了外特性变化及气液抽吸与内部流动之间定性的因果关系。探讨了旋流泵内部气液两相流动速度场和过流通道发生畸变的基本原理，为建立旋流泵内部气液及空化流动模型提供实例。
위탐색선류빙내부류장급기액량상류혼수특성，해문통과32WB8-12형선류빙외특성시험화빙최우공황류장오공탐침측량，득출빙성능곡선화5개측점정압ps、절대속도v、원주속도vu、경향속도vr화축향속도vz분포정황。침대N-S방정중사항력재기액량상류동중적구체표현특성진행역학분석，설명료빙내부량상류동특점급관련인소지간약속관계。천명료선류빙함기혼수추흡화양정형성적기본원리，급공화화기액량상류혼수적불동특점。선택성능시험최우공황，기우개진중조화군k-ε단류모형（RNG k-ε모형），응용Fluent연건대빙내부류장진행수치모의，득도료3개축면정압、속도시량화함기솔분포도。증명빙진구축향운동위주류，기체주요집중재압력교저적진구구역。기상적인입，기미단여액상척촌、형상급탄성모량적불동，조성량상류장관성력、마찰력화부력발생변화，유차해석료외특성변화급기액추흡여내부류동지간정성적인과관계。탐토료선류빙내부기액량상류동속도장화과류통도발생기변적기본원리，위건립선류빙내부기액급공화류동모형제공실례。
In order to study the characteristics of the flow field and gas-liquid two-phase flow hydrotransport in vortex pumps, the performance test and the measurement of flow field in volute at optimal operating condition with five-hole probes were conducted on a self-built vortex pump (32WB8-12). Based on these experiments, the qv-H,qv-P,qv-η,qv-NPSHc performance curves and the absolute velocityv, circumferential velocityvu, radial velocityvr, axial velocityvz, and the flow static pressure ps, on the 5 measuring points were obtained. The obtained parabolicqv-NPSH performance curve shows the opposite tendency compared to the centrifugal pump. The mechanical properties of the four kinds of forces in gas-liquid two-phase flow were analyzed with the Navier-Stokes Equation, and the results indicated the constraint relationship between performance and mechanical factors. Furthermore, the principle of gas-liquid flow hydrotransport and the difference between cavitating current and gas-liquid flow were also presented. The interior flow field in the pump under the optimal condition has been numerically simulated by FLUENT software based on the renormalization group k-ε turbulence model (RNG k-ε model) through which the pressure and velocity as well as gasvolume distribution of three cross sections in the vortex pump were obtained. The experimental results also showed that axial vortex was the dominant flow in the pump inlet, and the airflow gathered in the volute inlet with low pressure. The difference of molecule size, shape, and elastic modulus between airflow and liquid leads to the variations of the inertia, friction, and buoyancy forces in flow field, which explains the relationship between performance and parameters of the internal flow and gas-liquid suction as well as the head formation principle of vortex pump. The numerical results are in good agreement with flow field measurement data. The results show that the internal flow in the vortex pump mainly consists of through flow. The flow in the impeller region is of forced vortex characters, and the flow in volute is similar to the combined vortex with backflow, which is a non-axisymmetric unsteady flow with quite high turbulence intensity. All these should be main reasons for the relatively low efficiency of the vortex pump. The distortional principle of velocity field and the channel streamline with two-phase flow inside the vortex pump have been investigated in this article. This research provides a model of gas-liquid two-phase flow and cavitating current in vortex pump.