共查询到19条相似文献,搜索用时 109 毫秒
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本文研究了压气机叶栅中采用弯叶片对叶片表面流动稳定及转捩的影响.以风洞测得的叶片表面静压实验数据为基础,通过求解Falkner-Skan方程,获得不同来流马赫数下叶片边界层内气动参数.将以上结果作为边界层的平均流动值,结合数值离散化的正交曲线坐标系线性抛物化稳定性方程(PSE),对边界层流动的稳定性进行特征值分析.计算结果表明,在压气机中采用弯叶片,可改善叶栅吸力面两端区边界层的流动,但同时会恶化叶栅吸力面中部边界层流动的稳定性;合理地匹配选择叶片的弯向与弯量,才能有效地提高扩压叶栅的整体流动稳定性. 相似文献
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DES模型在压气机亚音转子中的应用探讨 总被引:1,自引:0,他引:1
本文运用分离涡模拟(DES)方法研究了不同工况下压气机亚音转子的流动情况,分析了其时均与瞬时流场中顶部间隙泄漏流动和根部角区的流动分离.通过与S-A模型计算结果的对比表明,DES模型在模拟顶部泄漏流动及二次泄漏、泄漏流在转子下游与尾迹的干涉时能够捕捉到更强的旋涡结构,在模拟转子根部角区的分离时也能获得更为丰富的流动现象.对不同工况的DES计算表明负荷的上升会使泄漏涡形成的位置向上游移动,从而导致并加剧二次流动,并对叶栅下游泄漏涡与尾迹的干涉产生影响.对设计工况下瞬时流场的分析表明,泄漏涡在叶栅下游体现出周期性的强弱变化,近叶根分离区也体现出明显的非定常性. 相似文献
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叶片弦向倾斜对损失发展的影响及叶片反弯降低损失机理的研究 总被引:2,自引:1,他引:1
早在六十年代初期,Smith提出了弦向倾斜叶片 ̄[1]。叶片的这种倾斜集叶片的后掠(叶片展向与气流不垂直)和上反(叶片表面与端壁斜交)于一身。根据理论分析可知,弦向倾斜叶片与周向倾斜叶片比较,在相同倾斜角下,它更能有效地抑制通道涡的形成和发展 ̄[2]。但是,到现在为止还没有实验数据证实这一计算结果。本文继文献 ̄[3]详细测量了弦向倾斜叶片叶栅由栅前至栅后诸截面上的气动参数。实验结果表明,弦向倾斜对损失的发展起到了与周向倾斜相类似的作用,但是前者比后者减小了叶栅进口段的流向逆压梯度,从而降低了二次旋涡损失。本文还测量了大转角常规直叶栅与反弯叶片叶栅端壁与叶片表面上的静压分布,探讨了反弯叶片降低损失的原因,认为:减小叶栅进口段流向逆压梯度,在叶片吸力面前部形成垂直于端壁的平行静压等值线、在中部形成反“C”型静压等值线,以及在流道内建立沿叶高的反“C”型静压分布,是反弯叶片降低损失的三要素。 相似文献
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从端壁动态压力场看压气机转子尖区流动 总被引:8,自引:1,他引:7
用高频压力传感器测量了低速单级压气机转子叶尖动态压力场。结果表明,转子叶背附面层径向潜流使得叶背附近存在一个高压带。叶背角区和叶盆角区的气流交混造成通道中部具有甚至不低于叶盆处的高压力。两个高压区都随流量的减小而扩大,并随流向逐渐融合,反映了叶背附面层径向潜流和中部气流交温的发展。设计状态下,泄漏涡是造成转子叶尖压力脉动的主要因素,形成的高水平压力脉动区随流向呈喇叭形逐渐扩大,约在一半弦长处脉动最强。近失速状态下,叶背前部角区中强叶面附面层潜流及与强泄漏流和端壁附面层的交混造成大范围的强压力脉动区,局部扩展到整个通道,通道中部叶背附面层很有可能发生分离。 相似文献
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To comprehensively control the corner separation and mid-span boundary layer (BL) separation, this study proposed and evaluated two new flow control configurations. One is a slotted configuration composed of blade-end and whole-span slots, and the other is a combined configuration with end-wall BL suction and whole-span slot. Additionally, the adaptability of the combined configuration to the lower blade solidity (c/t) condition was verified. The results indicate that both the slotted configuration and combined configuration can eliminate the mid-span BL separation, but a better reduction in the corner separation can be observed in the combined configuration. The two configurations can remove the concentrated shedding vortex and reduce the passage vortex (PV) for the datum cascade, but the wall vortex (WV) will be generated. By contrast, the combined configuration has weaker WV and PV than the slotted configuration, which contributes to further reducing the corner separation. In the combined configuration with a c/t of 1.66 and 1.36, the total pressure loss is reduced by 38.4% and 42.1%, respectively, on average, while the averaged static pressure rise coefficient is increased by 16.2% and 17.6%, respectively. This is advantageous for enhancing the working stability and pressure diffusion capacity for compressors. Besides this, the combined configuration with lower c/t can achieve a stronger pressure diffusion capacity and smaller loss than the higher c/t datum cascade. Therefore, the combined configuration is advantageous to the improvement of the aero-engine thrust-to-weight ratio through decreasing the compressor single-stage blade number. 相似文献
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The endwall effect has a great impact on the aerodynamic performance of compressor blades. Based on three conventional near-endwall blade modeling methods of bowed blade, endbend blade and leading-edge strake blade (LESB), two combined optimization design methods of highly loaded blades have been developed considering the endwall effect in the current study, i.e., the bowed blade combined with the LESB (bowed LESB blade) and the endbend blade combined with the LESB (endbend LESB blade). Optimization designs were conducted for a compressor cascade with low solidity by using the two combined modeling methods and the three conventional modeling methods, and the optimization results were compared and analyzed in detail. The results showed that the five optimization modelling methods could all improve the performance for the original cascade, and the optimized cascade with the bowed LESB modeling method has the best aerodynamic performance. The total pressure loss of the optimal bowed LESB cascade was only 40.3% of that in the original cascade while reducing the solidity of the original cascade from 1.53 to 1.25 and keeping the static pressure rise and diffusion factor at the same level as the original one. Among the optimal cascades, the radial migration height of the low-energy fluid and the corresponding vortex have great effects on the aerodynamic performance, and the optimal bowed LESB cascade is superior to the other optimal cascades in this aspect. 相似文献