摘要：The governing equations are derived by circumferentially averaging the three-dimensional(3D) Navier-Stokes equations,which are solved using a time marching finite volume *** Euler throughflow model and Navier-Stokes(N-S) throughflow model are employed to investigate the performance and flow fields of a highly loaded transonic single-stage fan ATS-2 and a four-stage *** results are compared with the experimental and three-dimensional computational *** shows that the throughflow models can provide reasonable performance characteristics and N-S throughflow model gives better predictions in endwall regions.A throughflow computation n in which all the non-axisymmetric terms are included has been performed at off-design condition and the radial distributions of the flow field can be well described.

摘要：The current paper presents experimental and computational results to assess the effectiveness of non-axisymmetric endwall contouring in a compressor linear cascade. The endwall was designed by an endwall design optimization platform at 0° incidence(design condition). The optimization method is based on a genetic algorithm. The design objective was to minimize the total pressure losses. The experiments were carried out in a compressor cascade at a low-speed test facility with a Mach number of 0.15. Four nominal inlet flow angles were chosen to test the performance of non-axisymmetric Contoured Endwall(CEW). A five-hole pressure probe with a head diameter of 2 mm was used to traverse the downstream flow fields of the flat-endwall(FEW) and CEW *** the measured and predicted results indicated that the implementation of CEW results in smaller corner stall,and reduction of total pressure losses. The CEW gets 15.6% total pressure loss coefficient reduction at design condition, and 22.6% at off-design condition(+7° incidence). And the mechanism of the improvement of CEW based on both measured and calculated results is that the adverse pressure gradient(APG) has been reduced through the groove configuration near the leading edge(LE) of the suction surface(SS).

摘要：目前弯掠叶片被广泛应用于现代叶轮机设计,以协调高负荷、高通流、高效率和喘振裕度之间的矛盾,但同时也会引发应力、振动和稳定性等问题。因此,为更好地发挥弯掠叶片的气动优势,同时减少其空间结构复杂性,需要对弯掠空气动力学有更深的机理认识。利用周向平均降维方法,推导获得了可定量描述的周向不均匀源项,揭示出周向不均匀性会诱发叶轮机进气流场产生不同于直叶片的再平衡,进而影响弯掠叶片各基元的设计迎角,并使叶轮机内部流场和性能特性产生变化。采用数值仿真和Stereoscopic Particle Image Velocimetry(SPIV)实验的方法对弯掠叶片的这一机理进行了验证。结果表明弯掠叶片中,周向不均匀源项会打破原有的进气流场的径向平衡,导致进气流场的径向迁移,使进气流场关键参数产生展向差异,改变迎角的展向分布,进而影响整个流场性能。同时,对影响进气流场的周向不均匀源项构建解析模型及机器学习代理模型,解除叶轮机进气均匀流场的传统假设,以利于三维弯掠叶片的气动设计与分析。

摘要：开发了三维数值模拟程序研究轴流跨音转子叶尖间隙流动,应用高雷诺数k ε湍流模型加壁面函数的方法,计算了轴流跨音转子NASARotor37在设计转速下的流场.叶尖间隙采用分区的H型网格和主流区连续对接耦合计算,没有用间隙模型,也没有考虑Vena收缩效应而减小间隙量.在用有限体积法对Navier Stokes方程和湍流方程进行空间离散的过程中采用了交错网格的方法将N S方程与湍流方程紧密地耦合在一起,从而提高了计算精度.计算结果和实验数据进行了详细的比较和分析.结果表明,中部叶展具有与实验结果非常一致的流场特征,根、尖区流场则因涡粘假设和激波问题的存在而使流动细节与实验结果略有偏差.

摘要：使用三维数值模拟软件NUMECA(Numerical Mechanics Application)对双涵道风扇/增压级带转子叶尖间隙的粘性流场进行了三维定常流动数值模拟,获得了其设计转速下的流场特性.结果显示,随着外涵背压的升高,风扇顶部激波后阻塞区周向和轴向尺寸增大,激波变形加剧,继续提高外涵压比,则外涵效率和进出口流量下降.内涵背压的升高,使内涵各转子叶片顶部的泄漏流动影响范围向上游扩散.内涵背压过高,效率和进出口流量同样会有下降的趋势.同时通过和实验结果的比较表明,数值模拟软件模拟的风扇/增压级的三维定常粘性流场能够较真实的反映出转子叶尖间隙泄漏流场的结构特征,以及间隙对流场参数的影响.

摘要：自主发展了基于周向平均方法的航空发动机整机准三维数值仿真方法。基于Navier-Stokes方程,推导了周向平均的准三维通流模型控制方程,针对方程源项传统模型的不足,提出了考虑叶型影响的无黏叶片力模型、基于机器学习的压气机展向分布损失模型和基于理论分析的周向不均匀性模型等,并完成了燃烧室的准三维建模,最终实现了航空发动机整机准三维稳态仿真。利用本文发展的整机周向平均稳态准三维仿真程序CAM完成了WP11涡喷发动机整机仿真,并与俄罗斯S2程序AES-S2的仿真结果进行了对比分析。结果表明,相比于俄罗斯S2程序AES-S2,所发展的周向平均准三维仿真程序CAM仿真精度更高,在WP11整机准三维仿真的设计点计算结果对比中,CAM计算的涡轮流量的误差比AES-S2的计算误差小8%以上,发动机推力误差小16%以上;收敛性更好,CAM计算的涡轮流量的振幅比AES-S2的计算结果的振幅小10%以上,CAM计算的发动机推力的振幅比AES-S2的计算结果的振幅小20%以上。

摘要：The shear-stress transport(SST)turbulence model is incorporated into Navier-Stokes equations to simulate a turbomachinery flowfield.A staggered finite volume method is used to make the mean flow equations and turbulence model equations strongly coupled and enhance the stability of the numerical *** implicit treatment of the source terms is applied to the SST model.A steady state solution is obtained using five-stage Runge-Kutta time-stepping scheme with local time stepping and residual smoothing to accelerate convergence. The wall distance d,a key parameter in the SST model,is solved by a partial differential *** validations of the code are conducted on rotor 37,wp11 at design and off-design conditions by comparison with measurements and the Spalart-Allmaras(SA)turbulence *** flow within the tip is calculated with a multi-block grid.

摘要：针对某高负荷双级风扇非设计转速裕度不足的问题,通过NUMECA三维(CFD)数值模拟软件,对比分析了可变弯度导叶(VIGV)前后可偏转调节对导叶气动性能的影响,以及导叶大角度范围内变弯度调节对提高风扇中低转速性能的作用。结果表明:可变弯度导叶偏转调节后的叶型实际弯角是影响导叶气动损失的重要因素之一;通过导叶前段适当变角度调节能减小导叶的实际弯角,推迟了导叶吸力面气流分离的出现,拓宽了变弯度导叶低损失可调角度范围;同时导叶适当的前后偏转调节能够降低导叶对缝隙位置的敏感性;此外前后可调变弯度导叶能够使高负荷风扇非设计工况实现更高的绝热效率,在90%转速、80%转速、70%转速和60%转速下的风扇绝热效率分别提高了2.04%、5.48%、6.18%和6.82%;且由于风扇喘振边界进一步远离风扇阀门线,使得风扇中低转速的稳定工作范围显著拓展。

摘要：通过对三维(3D)Navier-Stokes方程进行周向平均,得到了通流模型的控制方程,对其采用时间推进有限体积方法进行数值求解。为实现风扇/增压级在设计初期的快速性能评估,考察了周向平均方法在风扇/增压级分析中的准确性。分别利用NUMECA三维数值模拟软件和周向平均通流模型(CAM)对某高通流风扇/增压级进行了性能分析,从对比结果来看,周向平均通流模型在近设计点给出了与三维数值模拟十分接近的特性参数,最大误差不超过2.0%。在风扇转子中,由于周向平均通流模型能捕获通道激波,其物理本质与三维平均结果有所区别,因此径向参数分布与三维有所差异。而在亚声速流动下的增压级及外涵道各叶片排出口参数的径向分布与三维数值模拟结果都能很好地吻合。

摘要：This paper expounds both the aerodynamic principles and the techniques used in the design of the first case of China's high loading single stage backward swept fan. It is a scaledown fan designed in 1993~1995 for exploring the designing skill. It takes the basic design ideas of low aspect ratio, moderately backward sweep and two shock surfaces on the rotor's operating points. The special difficulties in the design of this kind of fans with pressure ratio >2.0 are analysed. The fundamental considerations about the casing and hub geometries,pre-swirl arrangement in a high loading compressor are proposed. The important basic factors influencing both the stage's overall geometry characteristics and the aerodynamic efficiency are mentioned. It explains also the essential contradictions among the applications of the sweep blading, the airfoil pre-compression, the stress reduction and the rotor's aeroelastic stability control. The main design parameters are listed.