共查询到19条相似文献,搜索用时 156 毫秒
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本文论述了沿叶片全长具有弦向割缝的轴流式压气机叶栅的研究成果,这一成果对于控制大弯度叶片附面层的分离乃是一种有效的措施.文中给出了利用有限元法预测叶栅流场的计算机程序,计算结果与测试数据吻合良好,其精确度令人满意.计算和试验表明,割缝叶栅的气流转折角比无割缝叶栅的气流转折角大5.8°左右,且叶栅性能得到改善. 相似文献
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针对45°叶型转折角扩压叶栅及增加小叶片后组成的大小叶片叶栅,分别测量了其在设计工况及不同气流攻角下的叶栅气动性能,通过PIV实验获得了对应工况下的叶栅内部流动状态.结果表明:增加小叶片后,叶片压力面至吸力面的压力梯度明显降低,大叶片载荷降低;在设计工况下,叶栅气流落后角仍可参考霍威尔半经验公式进行计算,但偏离设计工况后,该公式存在较大误差;大小叶片叶栅的气流落后角仅在小气流攻角下明显减小,在其余工况下变化不大;不同气流攻角下小叶片对大叶片表面气流流动分离起到约束作用;在设计工况至大气流攻角工况变化过程中,叶栅扩压损失有所降低. 相似文献
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The effects of a positively bowed blade on the aerodynamic performance of annular compressor cascades with different camber angles were experimentally investigated. The distributions of the exit total pressure loss and secondary flow vectors of the compressor cascades were analyzed. The static pressure was measured by tapping on the cascade surfaces, and the ink-trace flow visualizations were conducted. The results show that the value of the optimum bowed angle and optimum bowed height decrease because of the increased losses at the mid-span with the increase of the camber angle. The C-shape static pressure distribution along the radial direction exists on the suction surface of the straight cascade with larger camber angles. When bowed blade is applied, the larger bowed angle and larger bowed height will further enhance the accumulation of the low-energy fluid at the mid-span, thus causing the flow behavior to deteriorate. Under 60° camber angle, flow behavior near the end-wall region of some bowed cascades even deteriorates instead of improving because the blockage of the separated flow near the mid-span keeps the low-energy fluid near the end-walls from moving towards the mid-span region. As a result, a rapid augmentation of the total loss can easily take place under a large bowed angle. 相似文献
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Shaowen CHEN Fu CHEN Keli WANG Jun GU Zhongqi WANG 《Frontiers of Energy and Power Engineering in China》2008,2(3):306-312
The effects of a positively bowed blade on the aerodynamic performance of annular compressor cascades with different camber
angles were experimentally investigated. The distributions of the exit total pressure loss and secondary flow vectors of the
compressor cascades were analyzed. The static pressure was measured by tapping on the cascade surfaces, and the ink-trace
flow visualizations were conducted. The results show that the value of the optimum bowed angle and optimum bowed height decrease
because of the increased losses at the midspan with the increase of the camber angle. The C-shape static pressure distribution
along the radial direction exists on the suction surface of the straight cascade with larger camber angles. When bowed blade
is applied, the larger bowed angle and larger bowed height will further enhance the accumulation of the low-energy fluid at
the mid-span, thus causing the flow behavior to deteriorate. Under 60° camber angle, flow behavior near the end-wall region
of some bowed cascades even deteriorates instead of improving because the blockage of the separated flow near the mid-span
keeps the low-energy fluid near the endwalls from moving towards the mid-span region. As a result, a rapid augmentation of
the total loss can easily take place under a large bowed angle.
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Translated from Journal of Propulsion Technology, 2007, 28(2): 170–175 [译自: 推进技术] 相似文献
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Experimental research of surface roughness effects on highly-loaded compressor cascade aerodynamics 总被引:1,自引:0,他引:1
Aircraft engines deteriorate during continuous operation under the action of external factors including fouling, corrosion, and abrasion. The increased surface roughness of compressor passage walls limits airflow and leads to flow loss. However, the partial increase of roughness may also restrain flow separation and reduce flow loss. It is necessary to explore methods that will lower compressor deterioration, thereby improving the overall performance. The experimental research on the effects of surface roughness on highly loaded compressor cascade aerodynamics has been conducted in a low-speed linear cascade wind tunnel. The different levels of roughness are arranged on the suction surface and pressure surface, respectively. Ink-trace flow visualization has been used to measure the flow field on the walls of cascades, and a five-hole probe has been traversed across one pitch at the outlet. By comparing the total pressure loss coefficient, the distributions of the secondary-flow speed vector, and flow fields of various cases, the effects of surface roughness on the aerodynamics of a highly loaded compressor cascade are analyzed and discussed. The results show that adding surface roughness on the suction surface and pressure surface make the loss decrease in most cases. Increasing the surface roughness on the suction surface causes reduced flow speed near the blade, which helps to decrease mixing loss at the cascades outlet. Meanwhile, adding surface roughness on the suction surface restrains flow separation, leading to less flow loss. Various levels of surface roughness mostly weaken the flow turning capacity to various degrees, except in specific cases. 相似文献
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Naixing Chen Hongwu Zhang Yanji Xu Weiguang HuangInstitute of Engineering Thermophysics Chinese Academy of Sciences P.O. Box Beijing 《热科学学报(英文版)》2003,12(3):198-203
A design procedure for improving the efficiency of a transonic compressor blading was proposed based on a rapid generation method for three-dimensional blade configuration and computational meshes, a three-dimensional Navier-Stokes solver and an optimization approach. The objective of the present paper is to design a transonic compressor blading optimized only by selection of the locations of maximum camber and maximum thickness for the airfoils at different span heights and to study how do these two design parameters affect the blade performance. The blading configuration and the computational meshes can be obtained very rapidly for any given combination of maximum camber and maximum thickness. The computational grid system generated is used for the Navier-Stokes solution to predict adiabatic efficiency, total pressure ratio and flow rate. As a main result of the optimization, adiabatic efficiency was successfully improved. 相似文献
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HTGR-10模块式高温气冷堆作为第四代反应堆型具有系统简单、安全可靠和经济性能优越等特点。而氦气循环透平发电机组的氦气压缩机性能,将成为发电是否高效的决定因素之一。本文利用Numeca数值模拟软件对一亚音速轴流氦气压气机试验机进行了气动性能及准数关系研究,分析了气流在叶栅中的流动机理,探讨了等雷诺数下相似准数对压气机叶片性能的影响。结果表明:采用空气工质模拟氦气压缩,在马赫数小于0.4工况下对压气机的通流流动影响很小,基本可以忽略;采用大于0.5的反动度,增加正预旋可以使效率维持较高的水平;在马赫数较小的情况下,绝热指数k不会对相似模拟产生大的影响。 相似文献