CAJ | 학술논문

以导管推进器为研究对象,采用雷诺时均纳维斯托克斯(RANS)方法对其梢隙流动进行数值模拟研究.通过对网格类型、湍流模型的适用性研究以及对梢部流场的研究探讨,初步建立了基于RANS梢隙流动的数值模拟方法;数值计算结果与实验结果吻合较好.对比分析发现,结构化网格与非结构化网格相比能捕捉到梢隙流动中更加细节的流场信息,如壁面边界层流动等,更适合于梢隙流动的数值模拟.3种湍流模型SST k-ω, RNG k-ε及RSM的计算结果基本一致,都能有效模拟梢隙流动.通过间隙区域流场分析发现,梢隙流动的驱动力主要是叶面与叶背之间的压差,受壁面边界层流动的影响.流体进入间隙时流动分离形成间隙分离涡,间隙泄漏流穿过间隙与吸力面侧流体相互作用,卷起形成梢隙涡,在约37.5%弦长位置处形成并附着在桨叶壁面发展,大约在75%弦长位置与桨叶分离进入尾流场中.研究获得了梢隙涡的起始、发展、脱落的变化过程.
이도관추진기위연구대상,채용뢰낙시균납유사탁극사(RANS)방법대기소극류동진행수치모의연구.통과대망격류형、단류모형적괄용성연구이급대소부류장적연구탐토,초보건립료기우RANS소극류동적수치모의방법;수치계산결과여실험결과문합교호.대비분석발현,결구화망격여비결구화망격상비능포착도소극류동중경가세절적류장신식,여벽면변계층류동등,경괄합우소극류동적수치모의.3충단류모형SST k-ω, RNG k-ε급RSM적계산결과기본일치,도능유효모의소극류동.통과간극구역류장분석발현,소극류동적구동력주요시협면여협배지간적압차,수벽면변계층류동적영향.류체진입간극시류동분리형성간극분리와,간극설루류천과간극여흡력면측류체상호작용,권기형성소극와,재약37.5%현장위치처형성병부착재장협벽면발전,대약재75%현장위치여장협분리진입미류장중.연구획득료소극와적기시、발전、탈락적변화과정.
In this paper, a ducted propulsor is taken as the object of the research, where the RANS simulation method is used to study the tip leakage flow of the propulsor. Through the applicability study of the numerical grid type and the turbulence model, and by analyzing the flow field at the tip region, preliminary numerical methods based on RANS for tip leakage flow are finally proposed, and the corresponding results agree well with the experimental data. Through the comparison of unstructured and structured mesh's results, it is ob-served that structured mesh can capture more flowing detail (for example, the boundary flow). Therefore, the structured mesh is more appropriate for the numerical simulation of tip leakage flow. Meanwhile, three turbulence models, SST k-ω, RNG k-ε, and RSM are used, and their numerical results are essentially similar, which suggests that all three can be applied in the tip leakage flow simulation. Through the analysis of tip clearance region's flow field, it is found that tip leakage flow's driving power is primary the pressure dif-ference between the front and back side of the rotor, and the flow is affected by the wall boundary flow. When the flow enters the tip gap, flow separation is occurred, and a gap separation vortex is formed. The tip clearance flow goes across the gap and interacts with the passage flow, finally developing into Tip Leakage Vortex (TLV). TLV's inception position is about 37.5% cord length and attaches to the rotor wall, and then sheds from the rotor wall at approximately 75%cord length into the wake flied. The numerical results clear-ly demonstrate the changing process of the tip leakage vortex inception, development, and shedding.