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- 2015
叶片前缘倾掠对离心叶轮气动性能的影响
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Abstract:
为了研究叶片前缘倾掠对离心叶轮气动性能及稳定工况范围的影响,在叶片前缘处沿子午面弦长方向进行叶尖前掠、叶尖后掠、叶根前掠、叶根后掠,实现了4种不同的叶片前缘倾掠。研究结果表明,对跨声速离心叶轮,叶尖前掠和叶根前掠可提高叶轮最高等熵效率和压比;叶尖后掠对叶轮等熵效率影响很小,但可降低叶轮压比;叶根后掠使叶轮等熵效率和压比均有所降低。同时,叶尖前掠和叶根后掠可提高其失速裕度,叶尖后掠和叶根前掠则可减小其失速裕度。为了便于比较,还研究了一个亚声速叶轮。研究发现,与跨声速叶轮相比,叶片前缘倾掠对亚声速叶轮的等熵效率和压比影响更小,但对失速裕度的影响和跨声速叶轮相似。对跨声速叶轮,叶尖前掠是提高其等熵效率、压比和失速裕度的一种有效方法。
To study the effects of blade leading edge lean and sweep on the aerodynamic performance and stable operating range of centrifugal impellers, this paper presents four different blade leading edge lean and sweep by sweeping blade tip forward and backward, and sweeping blade root forward and backward along the meridional chord line. Firstly, the effects of blade leading edge sweep on the overall performance and flow field of a transonic centrifugal impeller are studied, and the results show that the blade tip forward sweep or blade root forward sweep can improve the highest isentropic efficiency and total pressure ratio of the centrifugal impeller; the blade tip backward sweep almost has no effect on the isentropic efficiency, but can decrease the total pressure ratio; the blade root backward sweep decreases both the isentropic efficiency and total pressure ratio. Additionally, the stall margin is increased by the blade tip forward sweep or blade root backward sweep, and reduced by the blade tip backward sweep or blade root forward sweep. Finally, the effect of blade leading edge sweep on a subsonic centrifugal impeller is investigated, and it indicates that, compared with transonic centrifugal impeller, the blade leading edge sweep has less effect on the isentropic efficiency and total pressure ratio in a subsonic centrifugal impeller. However, the effects on stall margin are almost the same for both transonic and subsonic centrifugal impellers. For an unshrouded transonic impeller, blade tip forward sweep is an effective way to increase its isentropic efficiency, pressure ratio and stall margin
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