共查询到19条相似文献,搜索用时 171 毫秒
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针对离心透平的环列叶栅叶型,采用四段三次NURBS曲线(非均匀有理B样条曲线),分别对前缘圆弧、尾缘圆弧、叶背、叶盆进行参数化表达,环列叶栅叶型的设计自由度为14个,可灵活进行局部调整。采用高精度流场模拟方法,基于优选法,获得气动性能较高的设计参数。结果表明上述方法简单易行,优选出的离心透平级设计工况及变工况气动性能都得到了显著提升,与已有文献相比,单排静叶总压损失系数降低18.85%,整级轮周效率提高4.08%,动叶叶片数也减少17个。 相似文献
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为了解决高速机载涡轮发电系统效率较低的问题,通过一维计算和三维数值模拟相结合的方法,对以拉法尔喷管作为静叶、三维叶片作为动叶的局部进气跨声速涡轮级进行了研究。在对原型涡轮级流场分析后,通过ISIGHT优化软件集成NX,NUMECA和ANSYS等模块,采用多岛遗传算法,以喷管扩张角、扩张部分长度、周向排布角度以及动叶叶片进口几何角、出口几何角和轴向弦长作为优化变量对涡轮级进行了优化设计。最终得到给定设计工况下的最优几何参数。优化结果表明:优化得到的涡轮级功率达到了74 530 W,效率达到了79.60%,较原型提升了5.1%。 相似文献
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Chong-hyun Cho Soo-yong Cho Chaesil Kim 《Frontiers of Energy and Power Engineering in China》2009,3(4):414-422
An axial-type fan that operates at a relative total pressure of 671 Pa and a static pressure of 560 Pa with a flowrate of
416.6 m3/min is developed using an optimization technique based on the gradient method. Prior to the optimization of the fan blade,
a three-dimensional axial-type fan blade is designed based on the free-vortex method along the radial direction. Twelve design
variables are applied to the optimization of the rotor blade, and one design variable is selected for optimizing a stator
which is located behind the rotor to support a fandriving motor. The total and static pressure are applied to the restriction
condition with the operating flowrate on the design point, and the efficiency is chosen as the response variable to be maximized.
Through these procedures, an initial axial-fan blade designed by the free vortex method is modified to increase the efficiency
with a satisfactory operating condition. The optimized fan is tested and compared with the performance obtained with the same
class fan to figure out the optimization effect. The test results show that the optimized fan not only satisfies the restriction
conditions but also operates at the same efficiency even though the tip clearance of the optimized fan is greater than 30%.
The experimental and numerical tests show that this optimization method can improve the efficiency and operating pressures
on axial-type fans. 相似文献
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An axial-type fan that operates at a relative total pressure of 671Pa and a static pressure of 560Pa with a flowrate of 416.6m3/min is developed using an optimization technique based on the gradient method. Prior to the optimization of the fan blade, a three-dimensional axial-type fan blade is designed based on the free-vortex method along the radial direction. Twelve design variables are applied to the optimization of the rotor blade, and one design variable is selected for optimizing a stator which is located behind the rotor to support a fan-driving motor. The total and static pressure are applied to the restriction condition with the operating flowrate on the design point, and the efficiency is chosen as the response variable to be maximized. Through these procedures, an initial axial-fan blade designed by the free vortex method is modified to increase the efficiency with a satisfactory operating condition. The optimized fan is tested and compared with the performance obtained with the same class fan to figure out the optimization effect. The test results show that the optimized fan not only satisfies the restriction conditions but also operates at the same efficiency even though the tip clearance of the optimized fan is greater than 30%. The experimental and numerical tests show that this optimization method can improve the efficiency and operating pressures on axial-type fans. 相似文献
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A redesign of a highly loaded fan stage by using high-turning bowed compressor stator was conducted. The original tandem stator was replaced by the highly loaded bowed stator which was applicable to highly subsonic flow conditions. 3D contouring technique and local modification of blade were applied to the design of the bowed blade in order to improve the aerodynamic performance and the matching of the rotor and stator blade rows. Performance curves at different rotating speeds and performances at different operating points for both the original fan stage and redesigned fan stage were obtained by numerical simulations. The results show that the highly loaded bowed stator can be used not only to improve the structure and the aerodynamic performances at various operating points of the compressor stage but also to provide high performances at off-design conditions. It is believed that the highly loaded bowed stator can advance the design of high-performance compressor. 相似文献
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The performance-enhancing effects of closely packing tidal turbines in single row arrays (tidal fences) are evaluated in this computational study. Infinitely long tidal fences are simulated with a range of lateral rotor spacings using a blade element momentum method embedded in a Reynolds averaged Navier–Stokes solver (RANS-BEM).First, a rotor design tool is applied to determine a hydrodynamically optimal rotor design for each lateral spacing. In the RANS-BEM method, the effect of blockage (the ratio of rotor swept area to channel cross-sectional area) on rotor optimization is accounted for. Increased blockage is found to result in increased optimal solidity and decreased optimal pitch. Next, each rotor design is simulated in its design spacing as well as several off-design spacings. The resulting power coefficient is largest when the rotor optimized for the highest blockage case operates in the array with the closest lateral spacing. Further, although a rotor's performance is improved through operation at a blockage higher than its design point, it still exhibits inferior performance relative to a rotor designed for that higher blockage. The results indicate that blockage must be considered in the rotor design process if the optimal rotor efficiency for a given spacing is to be achieved. 相似文献
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模拟退火算法在三维气动优化设计中的应用 总被引:1,自引:0,他引:1
首先对所开发的模拟退火算法进行函数验证,然后与实验设计、三维流场求解程序、二次多项式响应面近似模型结合,提出了一套省时的气动优化设计体系。应用该优化方法对跨音压气机动叶以绝热效率最大为目标进行气动优化设计,优化后叶片绝热效率提高约1.58%,并且具有良好的变工况性能。结果表明了所开发优化设计体系省时、高效的特点。 相似文献
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Small-sized axial fans are used as air cooler for electric equipments.But there is a strong demand for higher power of fans according to the increase of quantity of heat from electric devices.Therefore,higher rotational speed design is conducted,although,it causes the deterioration of efficiency and the increase of noise.Then,the adoption of contra-rotating rotors for the small-sized axial fan is proposed for the improvement of performance.In the case of contra-rotating rotors,it is necessary to design the rotor considering the unsteady flow condition of each front and rear rotor.In the present paper,the fan performance of the contra-rotating small-sized axial fan with 100mm diameter at a designed and a partial flow rates is shown,and the unsteady flow conditions at the inlet and the outlet of each front and rear rotor are clarified with unsteady numerical results.Furthermore,the relation between the performance and the unsteady flow condition of the contra-rotating small-sized axial fan is discussed and the methods to improve the performance are considered. 相似文献
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Shaobin LI Jiexian SU Zhongqi WANG 《Frontiers of Energy and Power Engineering in China》2008,2(4):534-540
A redesign of a highly loaded fan stage by using high-turning bowed compressor stator was conducted. The original tandem stator
was replaced by the highly loaded bowed stator which was applicable to highly subsonic flow conditions. 3D contouring technique
and local modification of blade were applied to the design of the bowed blade in order to improve the aerodynamic performance
and the matching of the rotor and stator blade rows. Performance curves at different rotating speeds and performances at different
operating points for both the original fan stage and redesigned fan stage were obtained by numerical simulations. The results
show that the highly loaded bowed stator can be used not only to improve the structure and the aerodynamic performances at
various operating points of the compressor stage but also to provide high performances at off-design conditions. It is believed
that the highly loaded bowed stator can advance the design of high-performance compressor.
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Translated from Journal of Propulsion Technology, 2007, 28(1): 26–31 [译自: 推进技术] 相似文献
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针对发电机冷却离心风机的特点,采用计算流体动力学的方法对其在设计工况时的整机内部流场进行了数值模拟,揭示了其内部流场的基本特征,重点探讨了在数值模拟过程中各种网格的优缺点及构建整台离心风机的几何实体和划分网格中的一些技巧。通过对数值计算结果然后处理,可以比较直观地得到风扇内部流动的一些重要特点,为进一步对风扇进行优化设计提供指导。 相似文献
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高低齿迷宫密封是透平机械中抑制流体泄漏的关键部件。以某机组隔板密封为对象建立高低齿迷宫的计算流体力学(CFD)模型,研究由变工况引起的转子轴向偏移对密封泄漏特性的影响,并通过调整转子凸台宽度和密封腔高度对密封结构进行优化。结果表明:原始结构设计下,转子轴向偏移±3 mm内,泄漏量并未发生大幅度的上升;在-2~1.5 mm范围内泄漏量有所下降,说明在工况变动不大时,密封性能有所提高,但超出±3 mm的范围,泄漏量呈突增趋势;泄漏量分别随转子凸台宽度和密封腔高度呈二次非线性变化,存在一个最佳值使泄漏量达到最小,最佳凸台宽度和密封腔高度分别为5.13和7.5 mm;结构优化后密封泄漏量在正常工况及变工况下均小于原始结构,密封性能得到提高。 相似文献