共查询到19条相似文献,搜索用时 218 毫秒
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以某重型燃气轮机的整个压气机为研究对象,通过计算软件对该压气机内部三维流场进行设计工况下的数值模拟研究,获得的压气机特性计算结果与试验值吻合良好;并详细分析了该压气机内部流场结构,找出了该燃气轮机最大噪声位置及其形成原因,同时获得了两种压气机内部流场的控制方法,对于压气机设计具有指导意义. 相似文献
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为研究间隙变化对轴流压气机转子近失速工况下叶顶流场结构的影响,以轴流压气机转子Rotor37为研究对象,对其叶顶流场进行定常和非定常的数值模拟。计算结果表明:随着叶顶间隙的减小,压气机的总压比和等熵效率均有所提高,稳定运行范围扩大;2倍设计间隙下,叶尖泄漏涡经激波作用后发生膨胀破碎,堵塞来流通道,诱发压气机堵塞失速;0.5倍设计间隙下,吸力面流动分离加剧,发生回流,部分回流与来流在压力面前缘上游发生干涉,进口堵塞加剧,致使部分来流从前缘溢出,导致压气机叶尖失速;不同间隙下压气机失速过程的主导因素不同,大间隙下失速由叶尖泄漏涡破碎的非定常波动引起,小间隙下失速主要由流动分离引发的周期性前缘溢流所主导。 相似文献
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A similitude method and the corresponding blade design of a low-speed large-scale axial compressor rotor 总被引:2,自引:0,他引:2
YU Chenghai MA Ning WANG Kai DU Juan Van den Braembussche R.A. LIN Feng 《热科学学报(英文版)》2014,23(2):145-152
A similitude method to model the tip clearance flow in a high-speed compressor with a low-speed model is presented in this paper. The first step of this method is the derivation of similarity criteria for tip clearance flow, on the basis of an inviscid model of tip clearance flow. The aerodynamic parameters needed for the model design are then obtained from a numerical simulation of the target high-speed compressor rotor. According to the aerodynamic and geometric parameters of the target compressor rotor, a large-scale low-speed rotor blade is designed with an inverse blade design program. In order to validate the similitude method, the features of tip clearance flow in the low-speed model compressor are compared with the ones in the high-speed compressor at both design and small flow rate points. It is found that not only the trajectory of the tip leakage vortex but also the interface between the tip leakage flow and the incoming main flow in the high-speed compressor match well with that of its low speed model. These results validate the effectiveness of the similitude method for the tip clearance flow proposed in this paper. 相似文献
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Bin Zhao Shuai Han Lizhi Xu Chengjiang Shi Diankui Gao Yuanyuan Zhang 《Numerical Heat Transfer, Part A: Applications》2017,72(7):551-562
Heat transfer of leakage flow in tip clearance will reduce the working performance, and therefore it is necessary to study it in depth. To improve the computing effectiveness of heat transfer of leakage flow in the tooth tip clearance of the single-screw compressor, the fuzzy contourlet finite element model is constructed by combining the contourlet finite element method and fuzzy finite element method. First, the related research progresses are summarized. Second, heat transfer model of leakage flow in the tip clearance of single-screw compressor is constructed. Third, the fuzzy contourlet wavelet finite element model is established. Finally, heat transfer simulation of leakage flow in the tip clearance of single-screw compressor is performed, and the variables with fuzziness are chosen, which are transformed to random variables based on information entropy theory. The comparing analysis among simulation analysis and test results is performed, and results show that the contourlet finite element method has highest computing precision and efficiency. In addition, the temperature of leakage flow in the tip clearance (L1) is also obtained, and results show that the fuzzy contourlet wavelet finite element method can effectively obtain the temperature distribution rules with fuzziness. 相似文献
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Effects of axial non-uniform tip clearances on aerodynamic performance of a transonic axial compressor 总被引:1,自引:0,他引:1
This paper presents a numerical investigation of effects of axial non-uniform tip clearances on the aerodynamic performance of a transonic axial compressor rotor (NASA Rotor 37). The three-dimensional steady flow field within the rotor passage was simulated with the datum tip clearance of 0.356 mm at the design wheel speed of 17188.7 rpm. The simulation results are well consistent with the measurement results, which verified the numeri- cal method. Then the three-dimensional steady flow field within the rotor passage was simulated respectively with different axial non-uniform tip clearances. The calculation results showed that optimal axial non-uniform tip clearances could improve the compressor performance, while the efficiency and the pressure ratio of the com- pressor were increased. The flow mechanism is that the axial non-uniform tip clearance can weaken the tip leak- age vortex, blow down low-energy fluids in boundary layers and reduce both flow blockage and tip loss. 相似文献
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为了研究几何尺寸模化缩放及叶尖间隙对多级轴流压气机气动性能及内部流动的影响,采用Numeca程序对17级轴流压气机开展了数值计算。结果表明:在80%及100%等高转速条件下压气机效率随着模化比例增大而增大,而在50%转速下模化缩放对压气机效率的影响较小。相对于原型压气机,模化放大时,压气机前8级单级压比均有所降低,而后8级压比均提高;模化缩小时,压气机的变化规律则相反。随着压气机几何尺寸的增大,静叶叶根和叶尖区域的总压恢复系数显著提高。同时,叶片叶尖泄漏流区域的熵增减少,从而使各级效率均有所提升。缩放模化中,随着叶尖间隙的增大,泄漏流增多,恶化了动叶叶尖附近的流动分离,降低了动叶后50%弦长区域的相对马赫数,同时扩大了静叶上端壁的流动分离,使压气机效率降低。 相似文献
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A numerical study of the effect of discrete micro tip injection on unsteady tip clearance flow pattern in an isolatedaxial compressor rotor is presented,intending to better understand the flow mechanism behind stall control meas-ures that act on tip clearance flow.Under the influence of injection the unsteadiness of self-induced tip clearanceflow could be weakened.Also the radial migration of tip clearance vortex is confined to a smaller radial extentnear the rotor tip and the trajectory of tip clearance flow is pushed more downstream,So the injection is benefi-cial to improve compressor stability and increase static pressure rise near rotor tip region.The results of injectionwith different injected mass flow rates show that for the special type of injector adopted in the paper the effect ofinjection on tip clearance flow may be different according to the relative strength between these two streams offlow.For a fixed injected mass flow rate,reducing the injector area to increase injection velocity can improve theeffect of injection on tip clearance flow and thus the compressor stability.A comparison of calculations betweensingle blade passage and multiple blade passages validates the utility of single passage computations to investi-gate the tip clearance flow for the case without injection and its interaction with injected flow for the case with tipinjection. 相似文献
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为了探究零间隙压气机流动失稳机理,采用全通道非定常数值模拟方法研究了一台零间隙斜流压气 机转子的失稳机理,数值模拟过程中在转子出口施加了随时间动态变化的背压模拟压气机转子节流,非定常 数值计算结果表明零间隙斜流压气机转子仍然表现为典型突尖流动失稳特征。通过详细地分析斜流压气机 转子节流过程中不同阀系数对应的压气机内部流场结构,结果表明:尽管零间隙斜流压气机无叶顶泄漏特 征,但随着对压气机节流,转子叶片尾缘率先出现流动分离,进一步节流,尾缘流动分离表现为一方面在周向 范围加剧,另一方面分离点逐渐向上游移动,造成通道严重堵塞,最终引发相邻叶片通道尾缘回流和叶片前 缘流动溢出进而诱发叶片通道内部出现径向涡结构,从而形成压气机突尖失速先兆。 相似文献
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Syed Noman Danish Shafiq Rehman Qureshi Abdelrahman EL-Leathy Salah Ud-Din Khan Usama Umer Chaochen Ma 《热科学学报(英文版)》2014,23(6):523-534
Extensive numerical investigations of the performance and flow structure in an unshrouded tandem-bladed centrifugal compressor are presented in comparison to a conventional compressor. Stage characteristics are explored for various tip clearance levels, axial spacings and circumferential clockings. Conventional impeller was modified to tandem-bladed design with no modifications in backsweep angle, meridional gas passage and camber distributions in order to have a true comparison with conventional design. Performance degradation is observed for both the conventional and tandem designs with increase in tip clearance. Linear-equation models for correlating stage characteristics with tip clearance are proposed. Comparing two designs, it is clearly evident that the conventional design shows better performance at moderate flow rates. However; near choke flow, tandem design gives better results primarily because of the increase in throat area. Surge point flow rate also seems to drop for tandem compressor resulting in increased range of operation. 相似文献