叶片扩压器进口角度对离心压缩机性能的影响

对叶片扩压器进口安装角α_（3A）＝13．0°,15．0°,19．9°,25．0°时压缩机的性能及带有无叶扩压器时压缩机的性能进行了实验研究,分别给出了不同情况下压缩机测试的性能曲线,通过分析叶片扩压器不同进口角度对级性能的影响,探讨了流动失速发生的位置及压缩机性能对叶片扩压器进口角度的响应。     

叶片扩压器在小流量离心压缩机中的应用研究

应用流动分析软件Fine/Turbo对叶片扩压器在压缩机基本级环境条件下进行了数值研究.在设计工况和变工况下获得叶片扩压器内部详细的流动规律,并对有叶片扩压器和无叶扩压器的级进行了性能比较.计算结果对于小流量离心压缩机的基本级采用叶片扩压器比采用无叶扩压器能获得更大的静压恢复系数,并提高了小流量压缩机基本级的气动性能.     

低稠度半高叶片扩压器的模型级性能研究

通过数值模拟的方法研究了低稠度半高叶片扩压器在大流量离心压缩机模型级中的应用,并比较了其与无叶扩压器对模型级气动性能影响的差异.研究结果表明:采用低稠度半高叶片扩压器的模型级基本消除了盖侧附近低总压高熵值的区域,气动性能有较大提高.     

含分流叶片的离心压缩机级的数值分析

对含分流叶片的离心压缩机级进行了三维数值试验.重点分析了叶轮、扩压器和蜗壳部件中的流动特征,另外,数值计算的结果表明:离心叶轮分流叶片的位置、扩压器宽度,以及蜗壳型式等方面的不同选择都会对压缩机的性能造成一定的影响.最后对数值计算的精度进行了分析说明.     

不同叶高直板扩压器对压缩机级性能的影响

利用计算流体动力学方法,对3种不同叶高的直板型叶片扩压器下离心压缩机级的三维粘性湍流流场进行了数值模拟计算;对压缩机级的多变内效率和总压比性能曲线进行了比较.通过对气流流动参数在不同叶高扩压器内的分布规律的分析,给出了扩压器叶片高度对气流的影响特点,为流体机械部件的优化提供了数值依据.     

分流叶片位置对离心压缩机级内部流动和性能影响的数值研究

运用数值求解叶轮机械内部三维粘性流场的方法,对工程上常用的某带分流叶片的离心压缩机叶轮及后接有叶扩压器的内部流动和性能进行数值研究。通过求解分流叶片处于不同周向位置和其前缘处于不同流向位置时级的流场,得到了对应的内部流场和压力、效率与流量的性能曲线。结合对级性能曲线和内部流场的详细分析,结果表明:分流叶片处于不同的周向位置和其前缘处于不同流向位置时对级的内部流场和性能曲线影响很大,分流叶片中间叶高处前缘位置位于50%左右和周向位置距长叶片吸力面一侧1/10栅距左右,级性能较佳。     

射流对扩压器流场稳定性的影响

在设计工况下叶片扩压器有利于提高离心压缩机级效率和压比.然而叶片扩压器稳定运行工况范围狭窄,超出该工况范围叶片扩压器产生的冲击作用会降低离心压缩机性能.因此在某些化工过程中,离心压缩机在压缩过程中获得外部注入的射流.在扩压器叶片上开孔,合理利用射流,能优化叶片扩压器中流场结构,扩大其工况范围.     

离心压缩机级的数值试验及分析

在自行开发的离心压缩机建模参数化软件平台上，对含分流叶片的离心压缩机级进行了数值试验，给出了级的总性能曲线和叶轮出口流场分布等结果。结果表明：离心叶轮分流叶片的位置、叶片出口的形状、扩压器宽度，以及蜗壳型式等方面的不同选择都会对压缩机的性能造成明显的影响。     

不同类型扩压器对离心式压缩机结构振动与辐射噪声影响的试验研究

扩压器是离心压缩机中的重要部件之一,不同类型的扩压器对压缩机的各方面性能影响很大。本文以MCL离心压缩机为研究对象,分别选取了全高叶片扩压器、楔形扩压器、半高叶片扩压器和无叶扩压器4种扩压器,在φ200模型级试验台上,开展了在不同流量下,不同扩压器对压力脉动(PP)、振动和声强影响的试验,获得不同类型的扩压器对结构振动与辐射噪声的影响的结果,选择楔形扩压器更具有优势,为离心压缩机的优化设计打下基础。     

基于CFD的离心压缩机整级性能优化设计

本文采用CFD技术研究离心压缩机整级性能优化设计方法.首先用一元理论进行初始设计,应用全三维流场分析的方法分析叶轮、扩压器以及回流器叶片参数变化对压缩机性能的影响.在此基础上,对主要几何参数进行了优化设计.研究结果表明;通过在压缩机运行过程中调节扩压器叶片的角度,可以使压缩机的最大效率和工况范围均得到改善.对于本模型的压缩机,效率可提高3％以上.优化设计后压缩机整级气动性能得到明显改善.     

不同扩压器形式对叶轮内流动影响的研究

针对离心式压缩机模型级进行了数值模拟,与试验结果对比验证了计算模型的正确性,用无叶扩压器代替叶片扩压器在相同的边界条件下进行流场数值模拟,根据模拟结果对比分析了两种情况下叶轮内部的流动特征,揭示了叶片扩压器和无叶扩压器对离心式压缩机级内流场的影响规律.     

径向间隙对离心压气机性能影响的数值研究

通过自主开发的CFD求解器NUAA Turbo,对带有楔形扩压器的离心压气机进行定常和非定常数值研究,通过改变叶轮和扩压器间的径向间隙,研究其对离心压气机性能的影响.研究发现:较小的径向间隙能够抑制扩压器压力面的分离,高载荷压力面的卸载提升了扩压器叶片通道的扩压能力.     

Static pressure recovery analysis in the vane island diffuser of a centrifugal pump

The overall performance of a vane-island type diffuser of a centrifugal pump model was obtained by means of directional probe traverses. These measurements were performed in an air model of a real hydraulic pump for five volume flow rates. Directional probe traverses are performed with a classical three-hole probe to cover most of the complete inlet section of the diffuser from hub to shroud and from pressure to suction side. Existing Particle image velocimetry (PIV) measurement results are also used to compare probe measurement results between the inlet and outlet throats of vane island diffuser at mid-span. Some assistance from already existing unsteady calculation, including leakage effects, is used to evaluate the numerical approach capability and to correctly define the mean initial conditions at impeller’s outlet section. Pressure recovery and the measured total pressure loss levels inside this particular vane diffuser geometry are then calculated. Detailed analysis of the flow structure at the inlet section of the vane island diffuser is presented to focus on pressure evolution inside the entire diffuser section for different flow rates. The combined effects of incidence angle and blockage distributions along hub to shroud direction are found to play an important role on loss distribution in such a diffuser.     

High performance hydraulic design techniques of mixed-flow pump impeller and diffuser

In this paper, we describe a numerical study about the performance improvement of a mixed-flow pump by optimizing the design of the impeller and diffuser using a commercial computational fluid dynamics (CFD) code and design-of-experiments (DOE). The design variables of impeller and diffuser in the vane plane development were defined with a fixed meridional plane. The design variables were defined by the vane plane development, which indicates the blade-angle distributions and length of the impeller and diffuser. The vane plane development was controlled using the blade-angle in a fixed meridional plane. The blade shape of the impeller and diffuser were designed using a traditional method in which the inlet and exit angles are connected smoothly. First, the impeller optimum design was performed with impeller design variables. The diffuser optimum design was performed with diffuser design variables while the optimally designed impeller shape was fixed. The importance of the impeller and diffuser design variables was analyzed using 2^k factorial designs, and the design optimization of the impeller and diffuser design variables was determined using the response surface method (RSM). The objective functions were defined as the total head (Ht) and the total efficiency (?t) at the design flow rate. The optimally designed model was verified using numerical analysis, and the numerical analysis results for both the optimum model and the reference model were compared to determine the reasons for the improved pump performance. A pump performance test was carried out for the optimum model, and its reliability was proved by a comparative analysis of the results of the numerical analysis and an experiment using the optimum model.     

扩压器稠度对离心压缩机性能影响的数值分析

通过CFD手段,比较了几个不同稠度的叶片扩压器性能与内部流场损失分布,分析了稠度的变化对叶片扩压器喉部流动产生的影响,并对叶片扩压器通过减小叶片数和减小叶片弦长来改变稠度的两种不同方法进行分析,发现通过减小叶片数的方法能够获得较好的压缩机性能。     

应用滑移网格技术分析多级离心泵的三维瞬态流动

运用滑移网格技术、三维非稳态Navier-Stokes方程和标准的k-e湍流模型对工业中常用的D型多级节段式离心泵进行了全三维瞬态流场的数值模拟,分析泵内叶轮与导叶间的动静干扰问题.滑移网格设置在多级离心泵叶轮出口与固定导叶入口之间的交互界面,对每个时间步求解流动方程.对任一个叶轮旋转周期内,分析叶轮径向力、静压等参数出现脉动信号频率与动、静叶片数的关系;分析静、动叶片间静压值沿周向的变化规律.该三维非稳态模拟结果可为多级离心泵的水力优化设计提供依据.