摘要：离心叶轮/扩压器匹配关系恶化直接限制了离心压气机的稳定工作范围.以Radiver离心压气机为研究对象,借助经过校核的数值模拟方法开展了基于可调叶高扩压器的离心压气机叶轮/扩压器匹配关系及流动机理研究.结果表明:通过建立能够指导扩压器叶高调节方向和量值的“压气机工作流量-扩压器最佳叶高”正相关对应关系,即可在压气机近失稳点等小流量点主动降低扩压器叶高以改善压气机稳定工作裕度.在设计转速下,引入可调叶高扩压器能够使离心压气机的稳定裕度提升18.8%、流量范围拓宽385%且峰值效率提高0.45%;随着压气机工作点向小流量工况偏移,降低扩压器叶高可以抑制扩压器来流正攻角,优化重构其通道内部涡系结构,减小扩压器吸力面和压力面/轮毂角区的低速区,进而改善叶轮/扩压器匹配关系,抑制扩压器内部流动失稳发生,提升离心压气机稳定裕度和效率指标.

摘要：In order to shorten aero-engine axial length,substituting the traditional long chord thick strut design accompanied with the traditional low pressure(LP) stage nozzle,LP turbine is integrated with intermediate turbine duct(ITD).In the current paper,five vanes of the first stage LP turbine nozzle is replaced with loaded struts for supporting the engine shaft,and providing oil pipes circumferentially which fulfilled the areo-engine structure ***,their bulky geometric size represents a more effective obstacle to flow from high pressure(HP) turbine *** five struts give obvious influence for not only the LP turbine nozzle but also the flowfield within the ITD,and hence cause higher *** investigation has been undertaken to observe the influence of the Nozzle-Strut integrated design concept on the flowfield within the ITD and the nearby nozzle *** to the computational results,three main conclusions are finally ***,a noticeable low speed area is formed near the strut's leading edge,which is no doubt caused by the potential flow ***,more severe radial migration of boundary layer flow adjacent to the strut's pressure side have been found near the nozzle's trailing *** boundary layer migration is obvious,especially close to the shroud ***,radial pressure gradient aggravates this ***,velocity distribution along the strut's pressure side on nozzle's suction surface differs,which means loading variation of the *** it will no doubt cause nonuniform flowfield faced by the downstream rotor blade.

摘要：With the improvement of requirement,design and manufacture technology,aero-engines for the future are characterized by further reduction in fuel consumption,cost,but increment in propulsion efficiency,which leads to ultra-high bypass *** intermediate turbine duct(ITD),which connects the high pressure turbine(HPT) with the low pressure turbine(LPT),has a critical impact on the overall performances of such future ***,it becomes more and more urgent to master the design technique of aggressive,even super-aggressive *** the last years,a lot of research works about the flow mechanism in the diffuser ducts were carried *** achievements were reported,but further investigation should be *** the aid of numerical method,this paper focuses on the change of performance and flow field of ITD,as well as nearby turbines,brought by rising angle(RA).Eight ITDs with the same area ratio and length,but different RAs ranges from 8 degrees to 45 degrees,are *** to the investigation,flow field,especially outlet Ma of swirl blade is influenced by RA under potential effect,which is advisable for designers to modify HPT rotor blades after changing *** addition to that,low velocity area moves towards upstream until the first bend as RA increases,while pressure loss distribution at S2 stream surface shows that hub boundary layer is more sensitive to RA,and casing layer keeps almost *** the other hand,the overall total pressure loss could keep nearly equivalent among different RA cases,which implies the importance of optimization.

摘要：An effect of the swirling flow on the combustion performance is studied by the computational fluid dynamics(CFD) in a micro-gas turbine with a centrifugal compressor, dump diffuser and forward-flow combustor. The distributions of air mass and the Temperature Pattern Factor(as: Overall Temperature Distribution Factor-OTDF) in outlet are investigated with two different swirling angles of compressed air as 0° and 15° in three combustors. The results show that the influences of swirling flow on the air distribution and OTDF cannot be neglected. Compared with no-swirling flow, the air through outer liner is more, and the air through the inner liner is less, and the pressure loss is bigger under the swirling condition in the same combustor. The Temperature Pattern Factor changes under the different swirling conditions.

摘要：The demand of further increasing bypass ratio of aeroengine will lead to low pressure turbines with higher diameter. Therefore, it is necessary to design a duct to guide the hot gas flow which is expelled from the upstream high pressure (HP) turbine stage to the downstream low pressure (LP) turbine stage. Named by its position, this kind of duct is always called intermediate turbine ducts (ITDs). Due to the pursuit of higher thrust ratio of the aeroengine, this kind of ITDs has to beas short as possible which leads to aggressive (high diffusion) S-shaped ITDs' geometry. In this paper, two different schemes of high diffusion separation-free S-shaped ITDs were studied with the aid of three-dimensional CFD programs. Although these two ITDs have the same area ratios (AR), because of the different duct length, they have totally different area as well as area change rates. With the detailed calculation results, comparisons were made to investigate the underneath physical mechanisms. Additionally, a direct estimation of the ITDs' loss is given at the end of this paper and some ITDs' novel design idea is proposed to initiate some further discussions.

摘要：In the present paper,computational fluid dynamics(CFD) simulations were executed to exploring the intent of using aspirated cascade to replace tandem ***,the ONERA tandem cascades were investigated,and the performance of the cascades at the design point were listed,such as diffusion factor,total pressure loss coefficient,deviation angle *** replacing the ONERA tandem cascades,a new cascade was designed with the codes BLADEGEN developed by the *** quasi 3-D calculations were carried out using the collection of programs for cascade analysis and design,*** cascade was analyzed and designed by using this *** the cascade was simulated and analyzed by commercial CFD *** is found there is an obvious separation on the suction *** on the 3D CFD simulation results of the cascade without aspiration,an aspirated cascade was designed by introducing a slot on the suction *** performance of the aspirated cascade was investigated and compared with the tandem cascades,indicated that under the same inlet condition,the total pressure loss of the single row aspirated cascade was less than that of the tandem cascades,and the outlet static pressure is higher than that of the tandem ***,the different suction slot location,suction width and suction mass flow are studied for the aspirated cascade.

摘要：跨声速离心压气机面临进口激波控制的难题,探索前缘掠型对跨声离心压气机影响机理对于进一步提升离心压气机性能具有重要意义。以两台跨声速离心压气机为研究对象,利用经过校核的数值模拟手段探究了不同前缘掠型下压气机的性能及流场变化。结果表明:设计工况下叶轮入口的激波位置直接决定了前缘掠型设计的作用效果。掠型设计通过改变导风轮叶顶载荷分布,进而影响其通流能力,同时改变了其入口激波结构和流动损失。当叶轮入口叶顶激波呈吞入状态时,采用前缘后掠会减弱槽道激波强度,从而减小导风轮叶顶附近损失;当叶轮入口叶顶激波呈脱体状态时,采用前缘前掠会减弱前缘激波强度,使得激波更加附体,从而减小导风轮叶顶附近损失。

摘要：在在第一个压缩机转子前面的尖端区域的稳定的分离微空气注射被证明了是一个有效方法处于低速度推迟旋转货摊的开始轴的压缩机。就实际申请而言，微注射者的一种新类型被设计并且在这描述了纸，它在 casing 是嵌入的并且能沿着弦被移动。为了验证它的可行性到另外的盒子，一些另外的盒子例如高亚声的轴的压缩机或离心的压缩机，被学习了。新注射者能拥有许多其它，这除成功地稳定压缩机以外有利的轴的压缩机显示出的一样的低速度的试验性的结果。当在片尖端的相对速度是高亚声的时，在一台高亚声的轴的压缩机上执行的实验证实了微空气注射的有效性。同时以便在离心的压缩机探索它的可行性，一个类似的微注射者与 vaned 在低速度上被设计并且测试离心的压缩机更弥漫。注射集体流动比在轴的压缩机和结果使用了那证明微注射能也在离心的压缩机推迟旋转货摊的发作的大一些。

摘要：顶部喷气是提高压气机稳定工作裕度的有效方式之一。文中设计了一种新型的喷嘴结构,利用高速单级轴流压气机试验台,研究了定常微量喷气对压气机性能和稳定工作裕度的影响。试验结果表明:在53%设计转速下,占压气机设计流量0.064%的喷气量可以使得压气机的失速裕度提高7.69%。同时,对带定常微量喷气的压气机转子内部流动进行了时间精确的非定常数值模拟,对比分析了喷气前后转子顶部区域不同的流动结构。将顶部间隙泄漏涡轨迹向压气机转子尾缘推移,抑制来流/顶部间隙泄漏流交接面向转子叶片前缘移动是定常微量喷气提高压气机失速裕度的主要机理。

摘要：针对一种可提高压气机裕度而又不牺牲效率的新型处理机匣，进行了较为系统的几何尺寸优化研究。借助单级轴流压气机实验台，详细地研究了轴向叠合量、容腔尺寸及内置导流片数目对压气机性能的影响，归纳出若干该型处理机匣的设计准则，具有工程实用价值。