顶部间隙对超声速膨胀器流动特性的影响

发布时间：2018-05-15 02:33

本文选题：超声速膨胀器 + 隔板　；参考：《航空学报》2016年02期

【摘要】：隔板与机匣之间留有间隙,间隙的存在势必会对超声速膨胀器的内部流场和总体性能产生影响,为了获得超声速膨胀器内部间隙流动的流动细节,采用三维雷诺平均Navier-Stokes方程和标准k-ε湍流模型,就顶部间隙对超声速膨胀器流动特性的影响进行了数值研究。结果表明:膨胀流道出口斜激波导致吸力面压力高于压力面,隔板尾缘附近部分泄漏流体经间隙流回压力面侧;间隙的存在导致吸力面进口及中、后部近下端壁压力上升,而压力面前缘附近压力下降,对比同一隔板位置,间隙高度每增加1%喉部高度,超声速膨胀器隔板载荷系数最高下降2.6%;端壁损失和斜激波损失降低,但产生了泄漏损失,三维流道内总的流动损失增加,膨胀器效率降低,本文研究范围内效率最多下降8.8%;马蹄涡、泄漏涡及二者之间的相互作用是顶部区域的主要涡系结构;前缘附近气流经间隙流到吸力面侧和尾缘附近泄漏流体越过间隙重新流回压力面侧是间隙内气流的主要运动形式。
[Abstract]:There is a gap between the diaphragm and the casing, and the existence of the gap will inevitably affect the internal flow field and the overall energy of the supersonic expander. In order to obtain the flow details of the gap flow in the supersonic expander, The effect of top clearance on the flow characteristics of supersonic expander is studied numerically by using the three dimensional Reynolds average Navier-Stokes equation and the standard k- 蔚 turbulence model. The results show that the suction surface pressure is higher than the pressure surface due to the oblique shock wave at the outlet of the expansion passage, and the leakage fluid near the tail edge of the diaphragm flows back to the pressure surface side through the clearance, and the existence of the gap causes the suction surface inlet, middle and lower end wall pressure to rise. However, the pressure near the front edge of the pressure decreases, compared with the same diaphragm position, the maximum load coefficient of the supersonic expander diaphragm decreases by 2.6% for every 1% increase in the clearance height, and the end wall loss and oblique shock loss decrease, but the leakage loss occurs. The total flow loss in the three-dimensional channel increases and the efficiency of the expander decreases, the efficiency of the expander decreases at most 8.8 in the range studied in this paper, the horseshoe vortex, the leakage vortex and the interaction between the two are the main vortex structures in the top region. The main movement form of the airflow in the gap is that the air flow near the front edge flows to the suction surface and the tail edge to the suction surface and near the tail edge to reflow back to the pressure surface through the clearance.
【作者单位】：大连海事大学轮机工程学院;
【基金】：高等学校博士学科点专项科研基金(20132125120006) 中央高校基本科研业务费专项资金(3132014319) 辽宁省高校创新团队支持计划(LT2015004)~~
【分类号】：O354.3;V211

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