共查询到16条相似文献,搜索用时 343 毫秒
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周向槽机匣处理对跨声速轴流压气机影响分析 总被引:3,自引:0,他引:3
党春宁 《燃气涡轮试验与研究》2008,21(3)
设计了一种周向槽机匣处理结构,并利用全三维定常数值模拟方法,研究了该机匣处理结构对某跨声速轴流压气机转子性能和流场的影响。结果表明,数值模拟结果与实验结果符合良好,该周向槽处理机匣使压气机转子的失速点流量减小了11.5%.有效地扩大了其稳定工作范围,但是同时也使得其峰值效率下降了0.82%。对压气机转子内部流场的分析表明,周向槽处理机匣扩稳的主要机理在于其对叶尖间隙泄漏涡与激波干扰后形成的低速流团的抑制,以及对叶片吸力面附面层径向涡在机匣面堆积形成的低速流团的吸除。 相似文献
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处理机匣对高压压气机性能和稳定性影响的数值模拟和试验研究 总被引:1,自引:0,他引:1
本文主要采用数值模拟和试验验证的方法探索轴向斜槽处理机匣改善高压压气机尖部流动情况及扩大压气机稳定工作边界的基本原理。采用Numeca CFD软件对某多级高压压气机第一级叶尖间隙流场和具有轴向斜槽处理结构的流场进行非定常计算.并对计算结果进行对比、分析,详细揭示了叶栅顶部间隙区及处理槽内的流动特征。数值计算结果显示,轴向斜槽处理机匣能够衰减或是消除叶尖的泄漏涡,推迟失速的发生。处理机匣对压气机性能的影响并不是直接采用对泄漏涡的干涉,而是通过叶尖附近气流在高压作用下从压力面尾缘进入斜槽,而后气流在叶背前缘以高速由斜槽射入主流。该高速射流能有效地扫除叶尖易失速的附面层,从而延迟气流分离,扩大压气机的失速裕度并减少二次流损失。试验结果显示,该多级压气机采用轴向斜槽处理机匣有效地减少了尖部气流泄漏,扩大了压气机稳定工作范围。 相似文献
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为降低对槽道式处理机匣流动进行模拟的计算量,特别地,为了提供一种可用于处理机匣工程设计的快速评估手段,基于对带有槽道式处理机匣的压气机非定常流动物理的理解,提出了一种处理机匣的准定常流动模型,并利用带有处理机匣的跨声压气机转子实验测量结果,以及非定常数值模拟结果对所提出的模型进行了验证.结果表明:处理机匣流动模型很好地预测了由于采用处理机匣所取得的转子失速裕度的提高,并且与非定常模拟结果比较,流动模型对转子主流以及处理机匣内部流动模拟的准确性也能得到保证.采用处理机匣流动模型所需的计算量仅约为非定常模拟的1%,这保证了提出的模型可用于快速评估槽道式处理机匣的气动特性,从而为其工程优化设计提供了有效的手段. 相似文献
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《航空动力学报》2012,27(6)
为降低对槽道式处理机匣流动进行模拟的计算量,特别地,为了提供一种可用于处理机匣工程设计的快速评估手段,基于对带有槽道式处理机匣的压气机非定常流动物理的理解,提出了一种处理机匣的准定常流动模型,并利用带有处理机匣的跨声压气机转子实验测量结果,以及非定常数值模拟结果对所提出的模型进行了验证.结果表明:处理机匣流动模型很好地预测了由于采用处理机匣所取得的转子失速裕度的提高,并且与非定常模拟结果比较,流动模型对转子主流以及处理机匣内部流动模拟的准确性也能得到保证.采用处理机匣流动模型所需的计算量仅约为非定常模拟的1%,这保证了提出的模型可用于快速评估槽道式处理机匣的气动特性,从而为其工程优化设计提供了有效的手段. 相似文献
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基于给定的进气周向总压畸变谱,应用全三维数值计算方法,研究了周向槽处理机匣对NWPU-1轴流压气机转子容畸变特性的影响,初步揭示了其在进气周向总压畸变条件下的失速机理。结果表明,在均匀进气条件下,周向槽处理机匣对叶尖间隙泄漏涡形成和发展的抑制是其扩稳的主要原因;在进气周向总压畸变条件下,该轴流压气机转子失速的主要原因是畸变引起的攻角变化,造成部分叶片的负荷过重,由于周向槽处理机匣的作用主要在叶尖部分,所以并不能有效的扩大该压气机转子的稳定工作范围。 相似文献
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Numerical Investigation of Inlet Distortion on an Axial Flow Compressor Rotor with Circumferential Groove Casing Treatment 总被引:1,自引:0,他引:1
Huang Jian* Wu Hu School of Power Energy Northwestern Polytechnical University Xi’ an China 《中国航空学报》2008,21(6):496-505
On the base of an assumed steady inlet circumferential total pressure distortion, three-dimensional time-dependent numerical simulations are conducted on an axial flow subsonic compressor rotor. The performances and flow fields of a compressor rotor, either casing treated or untreated, are investigated in detail either with or without inlet pressure distortion. Results show that the circumferential groove casing treatment can expand the operating range of the compressor rotor either with or without inlet pressure distortion at the expense of a drop in peak isentropic efficiency. The casing treatment is capable of weakening or even removing the tip leakage vortex effectively either with or without inlet distortion. In clean inlet circumstances, the enhancement and forward movement of tip leakage vortex cause the untreated compressor rotor to stall. By contrast, with circumferential groove casing, the serious flow separation on the suction surface leads to aerodynamic stalling eventually. In the presence of inlet pressure distortion, the blade loading changes from passage to passage as the distorted inflow sector is traversed. Similar to the clean inlet circumstances, with a smooth wall casing, the enhancement and forward movement of tip leakage vortex are still the main factors which lead to the compressor rotor stalling eventually. When the rotor works trader near stall conditions, the blockage resulting from the tip leakage vortex in all the passages is very serious. Especially in several passages, flow-spillage is observed. Compared to the clean inlet circumstances, circumferential groove casing treatment can also eliminate the low energy zone in the outer end wall region effectively. 相似文献
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为了深入认识周向槽轴向位置对压气机失速机制的影响规律,针对某叶尖敏感的低速单转子压气机开展实验测量与数值模拟相结合的研究。实验与计算结果均表明,位于叶片弦长中部的周向单槽扩稳效果最好,而位于叶片前缘下游20%~30%轴向弦长位置的周向单槽扩稳效果最差。进一步分析了利用非定常、多通道计算模型获得的数值结果,发现对于光壁机匣和扩稳效果最好的周向单槽机匣,泄漏流与主流交界面在近失速工况下到达叶片前缘位置,压气机通过突尖型失速先兆进入失速状态;对于扩稳效果最差的周向单槽机匣,泄漏流与主流交界面在近失速工况下仍位于叶片通道内部距离叶片前缘20%的轴向弦长位置,压气机经历了由准模态型失速先兆向突尖型失速先兆转换的失速起始过程。 相似文献
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周向槽机匣处理作为一种有效的扩稳措施得到了广泛应用,但是缺乏对其机理的深入理解和认识。为此,在一台低速单转子轴流压气机上考察了周向单槽机匣处理随轴向位置变化的扩稳效果。实验中获得了单槽不同轴向位置的扩稳规律,在该台压气机上得出了扩稳效果最好的槽位于40%~60%轴向弦长,而当单槽位于27%轴向弦长附近时,其扩稳效果最差。在此基础上,选取了最优扩稳槽位和最差扩稳槽位进行详细的壁面非定常流场测量和尾迹测量,对比分析了光壁条件与各单槽处理机匣对叶顶间隙泄漏流和转子尾迹的影响。结果表明,采用扩稳效果最优槽位之后,周向单槽能推迟叶顶间隙泄漏流与主流交界面前移,以及减弱叶顶间隙泄漏流非定常性,且能明显增强尾迹区1BPF(叶片通过频率)的能量,同时减弱0.5BPF的能量,达到扩稳的目的。而对于扩稳效果最差槽位而言,叶顶间隙泄漏流与主流交界面直到失速前也无法跨过单槽从叶片前缘溢出,周向单槽改变了叶顶间隙内部诱发突尖失速先兆的扰动传播方式;另外,其对转子尾迹区0.5BPF和1BPF的影响也比较小,从而使得其扩稳效果减弱。 相似文献
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采用带周向槽处理机匣的动叶叶顶喷气方法,研究了叶顶喷气对一轴流压气机跨声级转子在设计转速下的性能(包括失速裕度和效率)和内部流动特征的影响。结果表明,叶顶喷气能显著提高压气机的失速裕度,同时效率有所降低。不同流量和角度喷气的计算结果比较得出,近0°喷气角和0.5%喷气流量时,喷气效果最佳。对比无喷气时,失速裕度提高10%,峰值效率下降不到0.5%。内部流场结构的剖析揭示了叶顶喷气控制叶顶区的流动引起失速裕度提高和效率下降的内在流动机理。 相似文献
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Experimental and numerical study of tip injection in a subsonic axial flow compressor 总被引:2,自引:0,他引:2
Parametric study of tip injection was implemented experimentally on a subsonic axial flow compressor to understand the underlying flow mechanisms of stability improvement of the compressor with discrete tip injection.Injector throat height varied from 2 to 6 times the height of rotor tip clearance,and circumferential coverage percentage ranged from 8.3% to 25% of the annulus.Static pressure fluctuations over the rotor tip were measured with fast-response pressure transducers.Whole-passage time-accurate simulations were also carried out to help us understand the flow details.The combinations of tip injection with traditional casing treatments were experi mentally studied to generate an engineering-acceptable method of compressor stall control.The results indicate that the maximum stability improvement is achieved when injectors are choked despite their different sizes.The effect of circumferential coverage percentage on compressor stabil ity depends on the value of injector throat height for un-choked injectors,and vice versa.Tip blockage in the blade passage is greatly reduced by the choked injectors,which is the primary reason for stability enhancement.The accomplishment of blockage diminishment is maintained in the circumferential direction with the unsteady effect of tip injection,which manifests as a hysteresis between the recovery of tip blockage and the recovery of tip leakage vortex.The unsteady effect is primarily responsible for the effectiveness of tip injection with a partial circumferential coverage.Tip injection cannot enhance the stability of the rotor with axial slots significantly,but it can improve the stabil ity of the rotor with circumferential grooves further.The combined structure of tip injection with circumferential grooves is an alternative for engineering application. 相似文献