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叶顶间隙对压气机性能的影响 总被引:2,自引:0,他引:2
对某多级轴流压气机的其中两级的内部流场进行了全三维的CFD数值模拟,模拟结果与设计的级间参数比较吻合.通过对0.5倍设计间隙、1倍设计间隙和2倍设计间隙3个不同间隙的模拟结果的比较,探讨了间隙的大小对多级压气机总体性能的影响;通过内部流场的详细分析,揭示了间隙泄漏损失的特征. 相似文献
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使用三维粘性流动计算软件Fine/Numeca,研究了多级轴流压气机在设计工况及非设计工况的性能预估问题。对某七级轴流压气机进行了全工况特性数值计算。重点分析了低转速下近失速点、设计转速下近最高效率点、高转速下近堵塞点、进口导叶关小时设计转速下近失速点等四个典型工况点的流场特性。计算工作在自主开发的20节点集群计算机系统上进行。计算结果表明现有的软件和硬件平台能比较准确地预测压气机多叶片排的全工况特性。 相似文献
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针对跨声速压气机叶片内复杂的三维流动,采用自行开发的三维CFD程序对跨音速轴流压气机NASA Rotor 37流场进行数值模拟,对比分析了L-F(Lax Friedrichs)、Steger Warming及Van Leer 3种通矢量分裂格式和AUSMDV混合格式在跨声速叶轮流场数值计算时的格式效应。研究表明:与其他格式相比,AUSMDV在设计工况下的计算结果与实验误差最小,对激波和叶顶间隙泄漏的捕捉能力最强,Van Leer格式次之;Steger Warming格式在计算过程中收敛性最好。 相似文献
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基于压气机分层次气动优化设计思想,结合了优化算法、CFD(计算流体力学)技术与压气机气动设计程序,利用商业软件,建立了压气机气动优化设计平台,将气动优化设计思想融入到了压气机气动设计多个阶段,以实现压气机气动设计使性能最优化的目的.应用商业通用优化平台进行了轴流压气机一维、S2反问题气动优化设计,并采用NUMECA提供的全三维优化设计平台对压气机进行了全三维气动优化设计.计算结果表明:分层气动优化设计是提高压气机气动性能的有效手段,先进的优化算法在气动设计的各阶段都能够比传统设计手段更大限度地实现压气机性能的最优化. 相似文献
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Starting from the classical centrifugal compressor, cone shaped in meridional cross section, two modifications are considered on the basis of results from 2D and 3D flow models. The first modification is the change of the meridional cross section to hyperbolically shaped channel. The second modification, proposed on the basis of 2D axisymmetric solution, concerns the shape of blading. On the strength of this solution the blades are formed as 3D shaped blades, coinciding with the recent tendency in 3D designs. Two aims were considered for the change of meridional compressor shape. The first was to remove the separation zone which appears as the flow turns from axial to radial direction. The second aim is to uniformize the flow at exit of impeller. These two goals were considered within the frame of 2D axisymmetric model. Replacing the cone shaped compressor by a hyperbolically shaped one, the separation at the corner was removed. The disc and shroud shape of the compressor was chosen in the way which sat 相似文献
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为提高设计效率并快速得到适于工程应用的高压压气机转子结构,以改型设计方法为基础对某高压压气机转子结构进行了详细设计,同时对结构改进方法进行了一定的探索。采用叶—盘耦合系统循环对称结构算法及整体转子系统二维轴对称结构算法进行强度设计及改进,前轴颈最大应力下降最多达26%;其次进行支承结构设计,计算校核母型机轴承承载能力。结果表明:轴向力安全裕度最小为28%,轴承寿命大于100 000 h;给出2种调整鼠笼厚度的估算方法用以指导三维有限元计算,同时计算得到前支承刚度;通过二维有限元分析模型计算转子的临界转速,仅将后轴承支承位置沿压气机轴线向后移动7.5 mm,全运行工况转速与第2阶临界转速的安全裕度由18.5%提高到21.2%。 相似文献
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为了研究出口测量探针布局(探针数量及所处轴向位置)对压气机气动性能试验的影响,针对含测量探针的三级轴流压气机开展全周非定常数值计算。结果表明:出口测量探针将改变上游的流场结构,在末级叶片进出口截面对应探针的周向位置处形成局部高总压区和气流角偏移区,该区域覆盖有3~4个叶栅通道;随着探针与末级叶片轴向距离增加,高总压区的强度减弱,但作用范围增加;增加出口探针数量并未明显改善压气机试验性能评估精度,与无探针条件下的压气机性能相比,压比偏高0.6%,效率绝对值偏高1.8%;为减少试验中基于探针测点得到的压气机性能试验误差,不仅需考虑探针对测量截面流场的影响,更应根据测量截面流场不均匀性合理布局探针。 相似文献
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基于建立的舰船大功率多级轴流压气机气动设计体系,开展了舰船用某型大功率燃气轮机压气机设计研究,完成了6级轴流压气机的气动设计。进行了一维反问题设计、一维特性计算分析、S2反问题计算、叶片造型以及三维CFD计算分析。各级载荷分布从前面级到后面级逐渐降低,叶展方向按照等压比分配以避免径向掺混损失过大,S2设计并没有严格遵循传统的设计规律(等环量、等反动度等),而是基于一维设计方案通过不断调整优化获得的。根据CDA的特点,开发了可用于工程应用的叶片造型程序,可实现不同中弧线、不同厚度分布调节,能够实现叶片弯、掠等功能。三维数值模拟结果表明,考虑动叶叶顶具有0. 5 mm间隙的情况下,6级压气机设计点效率达到89. 75%,设计转速下的喘振裕度为22. 5%,同时具有较好的变工况性能。 相似文献
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Investigation of a centrifugal compressor and study of the area ratio and TIP clearance effects on performance 总被引:2,自引:0,他引:2
Mahdi Nili-Ahmadabadi Ali Hajilouy-Benisi Mohammad Durali Farhad Ghadak 《热科学学报(英文版)》2008,17(4):314-323
In this research, the centrifugal compressor of a turbocharger is investigated experimentally and numerically. Performance characteristics of the compressor were obtained experimentally by measurements of rotor speed and flow parameters at the inlet and outlet of the compressor. Three dimensional flow field in the impeller and dif- fuser was analyzed numerically using a full Navier-Stokes program with SST turbulence model. The performance characteristics of the compressor were obtained numerically, which were then compared with the experimental results. The comparison shows good agreement. Furthermore, the effect of area ratio and tip clearance on the performance parameters and flow field was stud- ied numerically. The impeller area ratio was changed by cutting the impeller exit axial width from an initial value of 4.1 mm to a final value of 5.1 mm, resulting in an area ratio from 0.792 to 0.965. For the rotor with exit axial width of 4.6 mm, performance was investigated for tip clearance of 0.0, 0.5 and 1.0 mm. Results of this simula- tion at design point showed that the compressor pressure ratio peaked at an area ratio of 0.792 while the effi- ciency peaked at a higher value of area ratio of 0.878. Also the increment of the tip clearance from 0 to 1 mm resulted in 20 percent efficiency decrease. 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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本文采用ANSYS-CFX对压气机进行三维流动数值模拟,获得了采用蜗壳冷却技术和不采用冷却技术两种情况下的压力和温度的三维流场分布情况,分析了蜗壳冷却技术对压气机流场的影响。结果表明,模拟计算结果与原机试验所测得的结果基本吻合,采用蜗壳冷却技术可以降低压气机出口空气的温度,增大出口空气的压力,进而提高增压器的充气密度,改善了增压器的性能,并为压气机蜗壳冷却技术的优化和改进提供参考。 相似文献
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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