老机组改造中具有弯扭静叶级的准三元和全三元计算

分析了弯扭叶片在国内外的应用现状，给出了具有弯扭静叶透平级的通流部分的分正问题计算方法及２００ＭＷ汽轮机高、低压缸改型设计中采用弯扭叶片级的部分准三元和全三元计算结果，讨论了采用弯扭叶片对改善流场的作用。     

弯扭叶片的设计思想、设计准则及其在汽轮机中的应用

根据对弯扭叶片的多年的研究和近几年来的使用经验，较系统地归纳出了弯扭叶片的设计思想和设计准则，对弯扭叶片的多种型面匹配准则和弯扭叶片叶列间的匹配准则进行了阐述，结合国产200MW汽轮机通流改造的实例，对上述思想及准则进行了验证。     

大焓降弯扭静叶设计理念及增荷设计研究

采用叶片几何成型参数化方法,对沿叶高变负荷设计的大焓降弯扭静叶片的成型要素进行了拆分,并对拆分得到的近似直叶片和原型弯叶片流场进行了数值模拟。结果证明,大焓降弯扭静叶负荷沿叶高的变化是叶片积迭线正弯曲造成的。以此为基础,对大焓降弯扭静叶进行了增荷设计,进一步证明采用大焓降弯扭静叶设计理念,对增高叶片气动负荷和控制二次流是有效的。     

弯扭叶片对汽轮机变工况的影响分析

分析了弯扭叶片中,叶片力的径向分力对沿叶高反动度的影响,及对变工况时脱流特性的影响。数值计算表明,在大功率汽轮机末级叶片中采用弯扭叶片后对脱流特性有较大影响。相对脱流高度减少。     

汽轮机叶片正弯对叶顶间隙泄漏流动影响的数值模拟

以某汽轮机高压级动叶为研究对象,采用κ-ε湍流模型,应用SIMPLEC算法对在相同叶顶间隙高度下的常规扭叶片和正弯扭叶片的叶顶间隙流动进行了数值模拟。研究结果表明:与常规扭叶片相比,叶片正弯提高了汽流在叶顶区的最低压力值,减小了叶顶压力边与吸力边的横向压力梯度;汽流在正弯扭叶片吸力面附近形成的泄漏涡的影响范围和对通道主流的扰动弱于在常规扭叶片内形成的影响;正弯扭叶片使汽流在吸力面和压力面上形成了叶顶部正径向压力梯度、叶根部负径向压力梯度的"C"型压力分布,同时降低了叶片上端部附近的总压损失。叶片正弯既降低了叶顶泄漏损失,又降低了叶栅通道内的掺混损失。     

某型舰用汽轮机末级_次末级叶片弯扭改型设计

应用S2流面正问题计算程序、S1流面计算程序和全三元Euler方程计算程序对某型舰用汽轮机低压末级、次末级静叶进行了弯扭改型设计,分析了舰用汽轮机变工况时叶栅流场的特点和采用弯扭叶片后机组性能的变化。结果表明：在低工况运行时,弯扭叶片抑帛了根部反动度随负荷降低而加速下降的趋势和顶部反动度随负荷降低而增大的趋势,提高了叶栅低工况运行时的抗分离能力,同时顶部漏泄损失也有所减小。     

扭叶片正弯对叶栅通道内二次流动影响的数值分析

以某汽轮机高压级动叶为研究对象,采用κ-ωSST模型、SIMPLEC算法数值模拟了正弯扭叶片叶顶间隙泄漏涡的形成和发展过程及其对叶栅通道二次流的影响。结果表明:相对于常规扭叶片,汽流在正弯扭叶片吸力面附近形成的泄漏涡的影响范围和对通道主流的扰动变小,且叶顶间隙的增加削弱了正弯扭叶片吸力面的"C"型压力梯度,使得叶片两端部附面层厚度增加,造成了叶片端部损失的增大。     

燃气透平静叶栅的弯扭气动设计分析方法

给出了一个适用于弯扭燃气涡轮静叶栅的气动设计分析通流计算方法。采用Ｓ２流面流函数方程做为主控方程，而热力气动参数的计算采用变热比求解方法，损失模型以修正的安利－马歇森模型为基础，二次流损失的计算考虑了弯叶片的影响。用此方法对一小展弦比涡轮级静叶栅进行不同弯曲角的弯扭联合成型气动设计，合理地反映了叶栅内流场特性。     

马刀型叶片隔板的研制与生产

1序言上海汽轮机有限公司生产的125MW汽轮机机组投运已有120余台，由于该机组系60年代设计，因此其经济性有待进一步改善。随着技术的进步，我公司决定对该机组进行改造，将低压末级和次末级隔板静叶由原来的扭叶片改为马刀型叶片，以降低叶片级损失，提高整机效率。由于马刀型叶片形状弯扭、型线复杂，给隔板铸造增加了难度，因此有必要立题加以研究。本文就以125MW机组末级（第24级）左旋马刀型叶片隔板的铸造为例来阐述工艺设计及生产过程。2马刀型叶片隔板的技术要求及毛坯验收条件2.1产品件的技术要求（1）汽道名义叶高654mm，出口总…     

基于ANSYS的10 MW风力机叶片弯扭耦合特性研究

为分析弯扭耦合效应对大型风力机叶片气动性能的影响。文中使用三维有限元软件ANSYS建立了10 MW复合材料风力机叶片模型,通过改变梁帽位置单轴向布的铺层角度在叶片中引入弯扭耦合效应,改变铺层角度和耦合区域,分析叶片在气动载荷作用下的变形情况。结果表明:叶片在弯扭耦合作用下产生弯曲变形的同时会发生扭转变形,沿叶片展向变形量增加;该叶片可达到的最大扭转变形量为6度;弯扭耦合系数随着铺层角度的增大而减小。     

Aerodynamic performance of bowed compressor cascades with different camber angles

The effects of a positively bowed blade on the aerodynamic performance of annular compressor cascades with different camber angles were experimentally investigated. The distributions of the exit total pressure loss and secondary flow vectors of the compressor cascades were analyzed. The static pressure was measured by tapping on the cascade surfaces, and the ink-trace flow visualizations were conducted. The results show that the value of the optimum bowed angle and optimum bowed height decrease because of the increased losses at the mid-span with the increase of the camber angle. The C-shape static pressure distribution along the radial direction exists on the suction surface of the straight cascade with larger camber angles. When bowed blade is applied, the larger bowed angle and larger bowed height will further enhance the accumulation of the low-energy fluid at the mid-span, thus causing the flow behavior to deteriorate. Under 60° camber angle, flow behavior near the end-wall region of some bowed cascades even deteriorates instead of improving because the blockage of the separated flow near the mid-span keeps the low-energy fluid near the end-walls from moving towards the mid-span region. As a result, a rapid augmentation of the total loss can easily take place under a large bowed angle.     

Aerodynamic performance of bowed compressor cascades with different camber angles

The effects of a positively bowed blade on the aerodynamic performance of annular compressor cascades with different camber angles were experimentally investigated. The distributions of the exit total pressure loss and secondary flow vectors of the compressor cascades were analyzed. The static pressure was measured by tapping on the cascade surfaces, and the ink-trace flow visualizations were conducted. The results show that the value of the optimum bowed angle and optimum bowed height decrease because of the increased losses at the midspan with the increase of the camber angle. The C-shape static pressure distribution along the radial direction exists on the suction surface of the straight cascade with larger camber angles. When bowed blade is applied, the larger bowed angle and larger bowed height will further enhance the accumulation of the low-energy fluid at the mid-span, thus causing the flow behavior to deteriorate. Under 60° camber angle, flow behavior near the end-wall region of some bowed cascades even deteriorates instead of improving because the blockage of the separated flow near the mid-span keeps the low-energy fluid near the endwalls from moving towards the mid-span region. As a result, a rapid augmentation of the total loss can easily take place under a large bowed angle. __________ Translated from Journal of Propulsion Technology, 2007, 28(2): 170–175 [译自: 推进技术]     

1 200mm叶片的非线性摩擦减振特性

根据国内外同行多年设计经验,综合考虑安全性、经济性与工艺性,设计了1200mm长叶片的结构,其中静叶为变截面空间三维弯扭联合成型叶片;动叶为考虑大变形、附加动应力最小的变截面空间反扭成型叶片;动叶的拉筋和围带设计成自带凸台拉筋和自带围带整圈软联接;叶根方案确定为斜四齿枞树型。在此基础上采用固定界面模态综合法计算了整圈叶片的非线性振动响应。设计与计算结果表明:采用自带凸台拉筋和自带围带整圈软联接结构形式的1200mm长叶片,在外激振力作用下,具有良好的摩擦减振性能。     

Application of high-turning bowed compressor stator to redesign of highly loaded fan stage

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.     

多级涡轮三维黏性流场的数值模拟

采用多叶片排网格生成技术，利用实质为标准κ-ω模型的改进型BSL双方程湍流模型对一个四级低压动力涡轮进行了数值模拟，其中多叶片排间参数传递采用“混合平面”方法。通过设计工况下计算结果和设计参数的对比，分析了此型多级涡轮的气动特点。末级导叶正弯优化设计显示弯叶片提高了此型多级涡轮的通流性能，同时也表明了弯叶片优化设计时进行多级黏性流匹配计算的必要性。     

自然样条型弯叶片生成方法及其在冷却风扇中的应用

提出了一种基于自然样条思想的弯叶片生成方法,推导了其积迭线的解析表达式.通过控制"弯度"参数可获得不同角度的弯叶片.将该弯叶片生成方法运用于某型冷却风扇,通过数值模拟研究了叶片各种弯曲形式对风扇气动性能的影响.结果表明:叶片前弯能有效抑制叶顶旋涡,降低叶顶区域的能量损失,扩大叶轮稳定工况范围;圆弧型弯叶片的风压略大于自然样条型弯叶片,但后者对降低叶顶区域能量损失更具明显优势.     

Application of high-turning bowed compressor stator to redesign of highly loaded fan stage

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. __________ Translated from Journal of Propulsion Technology, 2007, 28(1): 26–31 [译自: 推进技术]     

低速条件下展弦比对弯叶片扩压静叶栅流场性能的影响

为观察弯叶片在扩压叶栅中的适用条件,在保持其它条件不变的情况下,对一直列叶栅三种展弦比条件下的弯叶片流场进行了数值模拟。结果表明叶栅展弦比的大小对弯叶片在扩压叶栅中的作用影响较大,若展弦比增加,弯叶片改善叶栅性能的作用将增强。大展弦比叶栅中强弯叶片明显提高了吸力面角区密流系数的大小,从而改善了近端区的流场性能。在扩压叶栅中弯叶片可均化流场参数沿径向的分布,而在大展弦比叶栅中流场参数的径向分布差异较大,这应该是弯叶片在大展弦比叶栅中作用明显的主要原因。     

Bezier函数型弯叶片及其在带遮风罩垂直轴风力机中的应用

引入X弯度与Y弯度2个参数,提出了一种基于Bezier函数思想的叶型几何参数设计方法,通过分析传统垂直轴风力机效率低的原因,在此基础上提出了一种带有遮风罩的垂直轴风力机,并将基于Bezier函数生成的弯叶片应用于该风力机中.通过CFD数值模拟方法,研究了该风力机的气动特性,以及各种叶片的弯曲形式对其气动性能的影响.结果表明:遮风罩可以有效降低因来流对动叶轮吸力面的直接冲击而造成的阻力扭矩,风力机平均扭矩可提高107%;叶片的弯曲程度是由X弯度和Y弯度共同作用的结果,当X弯度与Y弯度在一定范围内具有局部最优值时,所形成叶片的垂直轴风力机的气动性能最佳,与普通半圆形叶片相比,风力机总扭转矩提高了33.8%.