原文：
　                     由于斜流泵兼有离心泵和轴流泵的优点,其应用范围越来越广。首先根据比转速的不同对斜流泵进行了分类,介绍了斜流泵的结构特点、能量特性以及存在的问题。对现有的斜流泵的设计方法即传统设计法、逆向求解设计法以及控制速度矩设计法的优势及不足进行了总结。在斜流泵的设计中需要注意的细节包括轮缘间隙、叶片角变化、绘型技术以及轴面图设计等。轴面图设计是影响斜流泵性能的一个重要因素,通过合理的改进轴面图形状,可以提高设计点效率、改善小流量点的驼峰。应用PIV测试以及CFD技术可以获取并分析斜流泵的内部流动特性。

            1、前言 斜流泵也称为导叶式混流泵,具有外径小、占地面积少、易启动以及效率高等优点,是一种性能和结构介于离心泵和轴流泵之间的水泵,具有两者的优点,补偿了两者的缺点。斜流泵的比转速传统应用范围在290～590,目前其应用范围已开始逐渐向传统的离心泵和轴流泵领域拓展。通过合理设计以及对叶轮叶片进行调节,消防泵斜流泵可以实现大范围的高效稳定运行。由于斜流泵具有上述优点,使其在海水脱盐系统以及火力发电和核电站的循环水系统中广泛采用,据日本透平机械协会统计,日本泵制造业在2003～2006年间为全球的火电站和核电站提供的循环水泵中斜流泵超过了93%,其中最大口径达4m。国内的斜流泵研究和生产与轴流泵和离心泵相比有很大的差距,其试验和理论研究都非常薄弱。

             2、斜流泵结构特点与能量特性 从水力结构看,斜流泵过流部件主要包括叶轮和导叶两部分,有的还包括进水导流部件,叶轮叶片有可调与不可调两种,通常情况下低比转速叶轮为不可调式的闭式叶轮,中高比转速叶轮为可调式的开式叶轮。图1为常见的几种不同比转速下斜流泵的水力结构形式。 部分斜流泵的无量纲能量曲线。流量系数<和扬程系数ψ的计算式为: 式中V2m———叶轮出口的轴面流速 U2m———叶轮出口均方根直径处圆周速度 H———设计点扬程 g———重力加速度 <———流量系数 ψ———扬程系数 在设计流量的0.5～0.7倍附近,流量-扬程曲线出现正斜率,也就是通常说的马鞍型曲线,斜流泵的这一不稳定特性会产生振动和噪声等不良现象。都築和豊倉等认为这是由于在该小流量点工况下叶轮进口回流损失引起的,前者还通过改善叶轮轮毂进口的设计消除了这一马鞍型。而Miyabe则通过PIV试验研究认为是由于叶轮进口处的脱流传播到导叶进口与叶轮出口之间进而在此处形成回流引起的。

           3、斜流泵设计方法

 3.1、传统设计方法 斜流泵导叶以及叶轮的传统设计方法主要是基于泵的一元设计理论,通过计算进出口速度三角形并借助模型换算等手段来进行设计的一种半经验半理论的设计方法。通常采用的叶片绘型方法有逐点绘型法和保角变换法。随着斜流泵的应用范围的拓展,特别是向高比转速方向发展的需要,很多研究人员开始对传统的设计方法进行调整和修正。例如关醒凡为了避免或者减少高比转速斜流泵内的回流、二次流以及改善汽蚀性能等,在设计过程中提出了四点需要改进的地方。何希杰针对斜流泵不同的轴面形状,推导了叶型的空间方程,并对一些优秀水力模型进行了回归分析,丰富了斜流泵的设计资料。

3.2、逆向求解设计法 逆向求解设计法是预先设置叶片表面的载荷分布,真空泵然后以涡列替代叶片求解叶片表面的载荷以满足给定条件的一种逆向设计方法。该方法最早由後藤彰等提出并在低比转速斜流泵的设计中应用。然而,虽然现在CFD技术可以对透平机械内部流动进行三元求解,也能分析叶片几何形状的变化对流场的影响,但是,还无法确切的知道什么样的叶片载荷分布是最合理的,因此也就无法依靠逆向求解方法获得最优的流道形状。桜井应用逆向求解设计法根据两种不同的预设叶片表面载荷设计了两种高比转速斜流泵叶轮并试验研究比较了其性能,对于高比转速斜流泵,采用逆向求解设计法可以有效提高设计点的效率,但是无法改善马鞍形曲线。随后後藤又将该方法发展到所有类型泵叶片/流道的设计中并建立了三维CAD/CFD交互系统,在该系统中含有一个前人工作积累的数据库用于设置初始叶片轴面形状和叶片表面载荷分布。

 3.3、控制速度矩设计法 斜流泵的流道形状介于离心泵和轴流泵之间,因此在设计方法上,目前有采用介于自由旋涡理论Vur=const和强旋涡理论Vu/r=const之间的某种变化规律的设计形式,也就是控制速度矩设计法。关醒凡在设计比转速为800的斜流泵时采用了控制速度矩设计方法,在设计中所绘制的流线采用了不同的流动规律,通过该方法设计斜流泵在设计流量下的二次回流得到有效的抑制,在其设计的比转速为800的斜流泵的性能曲线上,在叶片调整角度为-4°的流量-扬程曲线上没有出现明显的马鞍形。都築采用可控速度矩法对比转速为455的斜流泵进行了重新设计并分析了改型前后的流场和压力场,改型后的斜流泵完全消除了最高效率点0.545～0.6流量处的马鞍现象,曹树良等在进行斜流泵的设计时,也是预先给定了速度矩的设计。但是在这些研究中,都没有明确的说明如何控制速度矩。 蔡佑林根据可控涡设计理论和方法,管道泵 认为在叶轮叶片进口边要满足来流无冲击条件,根据库塔条件,在叶轮叶片的出口边Vur沿流线的梯度应该为0,根据上述约束,为比转速为482的斜流泵的设计提供了速度矩Vur的分布规律。根据逆向求解设计法和控制速度矩设计法设计得到的叶片与传统设计方法得到的叶轮,特别是叶片轮毂处型线的变化规律有所不同。

 3.4、关键参数影响及设计细节处理

3.4.1、绘型技术 叶片绘型是获得光滑叶片表面的关键技术,在传统的设计中,通常采用方格网以及保角变换技术逐条流线进行绘型,也有人提出了一些叶片型线的具体的描述公式,由此得到的叶片型线在每个流线上是光滑的,为了保证在整个流面上的光滑性,还要做进一步的光滑性检查。为了适应数控机床加工的需要,现在对叶片表面的光滑性要求已经很高,要求设计得到的叶轮能够与数控机床的加工精度相适应。曹树良等采用流线迭代法求解轴面流动,根据轴面流动得到的轴面流网求解叶片骨面与计算流面的空间交线,也就是叶片骨线,然后应用逐点积分法进行叶片绘型,设计得到的斜流泵叶轮和导叶叶片表面光滑,适用于数控机床加工。

 3.4.2、轴面图形状 在设计斜流泵叶轮和导叶的轴面形状时,通常根据经验或者已有的模型来确定。在早期的设计中,叶轮和导叶间的距离很短,叶轮出口边和导叶进口边在轴面上的投影是平行的。但是现在的设计则认为增大叶轮出口边和导叶进口边的距离是有利的。叶轮进出口边的设计通常遵循下述原则:轮毂侧进口边前伸以提前对流入叶轮的液流施加力矩,减小液流的相对速度,改善汽蚀性能;增加轮毂侧翼型的叶栅稠密度,使叶轮内部的流态更为稳定,防止在非设计工况下产生二次回流。都築用可控速度矩方法重新设计的叶轮轴面图的进口边与传统的设计结果相比符合上述要求。重新设计后的结果消除了马鞍形,优于改进前的性能。 为了分析轴面图对性能的影响,斉藤等对比转速为330的斜流泵进行了流场计算及内外特性试验研究,研究结果发现,轴面图曲率变化越小,内部流态越好,效率越高,但是最高效率点向大流量方向偏移。

 3.4.3、叶片安放角 何希杰研究了叶片安放角对性能的影响,并提出了相应的统计公式。通常进出口叶片安放角由速度三角形计算出的液流角得到。在传统的一元理论设计中,叶片安放角沿流线从进口到出口的变化是单调的,即二阶导数不存在0值。但是根据逆向求解法设计得到的叶片安放角变化规律则不同,图4所示为桜井设计的比转速为637的斜流泵的叶轮轮毂处叶片安放角变化曲线。 这种变化规律与传统设计明显不同,化工泵 叶片安放角在出口前先增大后降低的目的是为了满足库塔条件。但是,在整个流线上如何确定最优的叶片安放角变化规律目前还无法在设计阶段直接得到。 3.4.4、斜流泵叶轮轮缘间隙的影响 叶轮轮缘处间隙会影响泵的容积损失,从而影响泵的性能。钱涵欣等人研究了斜流泵轮缘间隙大小的不同对性能的影响。随着间隙的增大,效率下降,同时由于叶片的有效翼展减小,扬程和功率也是下降的。从提高效率的角度看,间隙越小越好。从加工工艺上讲,间隙越小制造越困难。所以设计时应根据具体条件尽可能取较小的间隙,以便提高泵的效率。 由于叶轮叶片的工作面和背面存在压力差,导致叶轮轮缘处间隙会产生间隙射流,从而影响轮缘附近的流动状态。原和雄为这种间隙流动建立了简化的数学模型,張春晚对该模型进行了发展并用于求解斜流泵的轮缘间隙流动,研究发现间隙内射流不仅与叶片工作面和背面的压力差有关,还与叶片圆周速度以及叶片的角度密切相关,间隙射流会引起不可忽视的能量损失。 此外,泵的进口流道形式对叶轮进口流态也有一定的影响,为了改善斜流泵的进口流态,要求泵的进口与吸水池壁面有一定的距离,有时候还会在泵的进口加装导流部件以满足泵进口流态的要求。

          4、斜流泵内部流动研究 同离心泵和轴流泵的研究一样,对内部流场的分析成为改善斜流泵性能的重要手段之一。对内部流场的研究主要有数值计算和试验研究两种方法。现在应用商用软件求解斜流泵的外特性曲线已经达到了较高的精度,特别是在设计工况点,效率和扬程的计算误差可以达到1.5%以内。 通常斜流泵没有前盖板,是一种开式结构,因此斜流泵内部流场的可视化试验研究比较容易实现。目前采用的最常用也是最简单的方法螺杆泵 就是油膜法,但是油膜法只能观测过流部件壁面的流动。PIV是分析叶片泵内部流场的较有效的可视化设备,Miyabe为了分析斜流泵马鞍形曲线的成因,采用PIV技术对斜流泵内部的流场进行了试验研究,发现了斜流泵内部流动失速的发生和发展过程,初步对斜流泵性能曲线驼峰的形成原因进行了分析。

           5、结论 (1)总结分析了斜流泵的结构特点和能量特性。斜流泵出现马鞍形曲线的原因复杂,但是可以确定的是与轴面图设计、进口叶片安放角设计等有关系; (2)现有的研究表明,除了高比转速斜流泵外,通过控制速度矩设计可以有效的消除斜流泵的马鞍形曲线。斜流泵外特性与叶片表面载荷分布以及速度矩分布等密切相关。但是如何最优的控制速度矩仍然是不确定的; (3)斜流泵的设计与绘型技术要求满足数控加工和快速成型的要求; (4)对内部流场的计算是分析斜流泵性能的重要手段之一。通常斜流泵的叶轮是开式的,因此其可视化试验研究比较容易进行。

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译文：
As the oblique axial flow pump and the advantages of both centrifugal pump, its use more widely. First of all, according to the different specific speed mixed flow pump on the classification, introduced the structural characteristics of mixed flow pump, the energy characteristics and problems. Oblique flow pump on the existing design method, that the traditional design method, reverse solving design and control of velocity moment method advantages and disadvantages are summarized. In the design of oblique flow pump to note the details including the flange clearance, blade angle changes, mapping of technology and design of axial map. Figure impact axial oblique flow pump design is an important factor in performance, through reasonable improvements in axial plane graph shape can improve the design point efficiency, Gai Shan Xiao Q conditions of the hump. Application of PIV and CFD technology for test and analysis of the internal oblique flow pump flow characteristics. 1 Introduction Oblique flow pump, also known as mixed flow pump with small diameter, small occupation area, easy start, and high efficiency, performance and structure of a range of between centrifugal and axial flow pump, has two are the advantages of compensation for the shortcomings of both. Oblique flow pump range of applications than the conventional speed of 290 ~ 590, the current range of applications has begun gradually to the pump and the axial field of development. Through the rational design and adjustable blade impeller, mixed flow pumps can achieve a wide range of high performance and stability. As the oblique flow pump has the advantage, so in the sea water desalination systems, and thermal and nuclear power plants is widely used in circulating water systems, turbo machinery, according to statistics compiled by the Japanese, the Japanese pump manufacturing industry between 2003 and 2006, the world's power plant and nuclear power plant to provide the circulating pump in the oblique flow pump more than 93%, with the largest diameter up to 4m. Domestic research and production of oblique flow pump axial and centrifugal pumps compared with the large gap between the experimental and theoretical study of its very weak. 2, mixed flow pumps and energy characteristics of structural characteristics From the hydraulic structure, the mixed flow pump impeller flow passage components and guide vane includes two parts, and some also include water diversion component, the impeller blades are adjustable and non adjustable two, usually of low specific speed impeller is not Mode of the closed impeller, high specific speed impeller is adjustable open impeller. Figure 1 is a common, under several different specific speed mixed flow pump of the hydraulic structure. Part of the oblique flow pump dimensionless energy curve. Flow coefficient Magnetic pumps the calculation formula is: Type in V2m --- impeller axial flow of exports U2m --- Office Impeller diameter circular velocity rms H --- design point head acceleration of gravity g --- <--- Flow coefficient ψ --- head coefficient In the design flow from 0.5 to 0.7 times in the vicinity, flow - lift curve is slope, which is often said that the saddle-shaped curve, mixed flow pump characteristics of this instability will have negative phenomena such as vibration and noise. Tsuzuki and Feng positions so that this is due to the low flow rate point in the impeller inlet reverse flow condition caused by the loss, the former also by improving the design of the impeller hub to eliminate the import of this saddle. And Miyabe Study through the PIV that is due to de-of impeller inlet guide vane flow spread to import and export between the impeller and then return here due to the formation. 3, mixed flow pump design 3.1, the traditional design method Oblique flow pump impeller vane and the traditional design method is mainly based on a dollar pump design theory, by calculating the velocity triangle and use of model import and export of means of conversion to the design of a semi-theoretical semi-empirical design method. Commonly used methods of blade drawing point by point mapping of method and conformal transformation method. Oblique flow pump with the expansion of scope of application, Tebie to the direction of high specific speed requirements, many studies have begun to right the Shejifangfa Jin Xing Chuan Tong adjustment and Xiu Zheng. For example, wake up where relevant in order to avoid or reduce the high specific speed mixed flow pump of the back, the secondary flow and to improve the cavitation performance, etc., in the design process put forward four areas for improvement. Xi-jie for oblique axial flow pump of different shape, leaf type of space is derived equations, and some excellent hydraulic model of the regression analysis, a mixed flow pump-rich design information. 3.2, the reverse design method for solving Reverse solving design is pre-set the load distribution of leaf surface, and then vortex replacement blade for solving the load leaf surface to meet the given conditions of a reverse design. This method was first proposed by Goto Akira and so on and in low specific speed mixed flow pump for the application. However, while CFD technology can now Turbomachinery flow ternary Qiu Jie, but also of changes in blade geometry and velocity fields, but also can not know exactly what kind of blade load distribution is the most reasonable, and therefore will not be able to rely on reverse to obtain the optimal solution of the flow channel shape. Sakurai using reverse design method for solving a default under the two different leaf surface load design of two high specific speed mixed flow pump impeller and Suber-water pumpsexperimental study compared the performance, for high specific speed mixed flow pump, the use of reverse design method can solve improve the efficiency of the design points, but unable to improve the saddle-shaped curve. Goto then then the method of development to all types of pumps Leaf / flow design and build three-dimensional CAD / CFD interaction system, the system contains a database of previous to earned for setting the initial blade shaft Plane Figure and load distribution on blade surface. 3.3, control velocity moment method Oblique flow pump flow between centrifugal and axial flow between the shape, so the design method, currently used between the free vortex theory Vur = const and strong vortex theory Vu / r = const a change between The design form of the law, that is, the speed control moment design. Wake up all the relevant speed of 800 than in the design of oblique flow pump used to control the velocity moment of design, the design flow line drawn in the use of a different flow pattern, designed by the oblique flow pump design conditions of the two effective inhibition of times back in its design speed of 800 than the oblique flow pump performance curve, the blade angle of -4 ° to adjust the flow - lift curve does not appear obvious saddle. Tsuzuki compared with moment method speed controlled velocity oblique flow pump for the 455 was redesigned and modified before and after analysis of the flow field and pressure field, after some modifications of the oblique flow pump best efficiency point of completely eliminating the flow of Division 0.545 ~ 0.6 saddle phenomenon, Shu-Liang Cao, etc. during the design of oblique flow pump is pre-given moment of the design speed. However, these studies are not clear on how to control the velocity moment. Cai Youlin under controlled vortex design theory and methods, that in the impeller blade inlet edge to meet the current and no impact to the conditions, according to David Coulthard conditions, the export side of the impeller blade Vur gradient along the flow line should be 0, the above constraints, the specific speed mixed flow pump for the 482's design provides the distribution of velocity moment Vur. According to reverse and control the speed of solving design design design moments obtained with the traditional design methods are blade impeller, especially rotor hub office profile variation is different. 3.4, the key parameters and design details of the treatment effect 3.4.1, paint technologies Is a smooth mapping of leaf blade surface was the key technologies in traditional design, usually square grid and the conformal mapping technique one by one mapping of flow lines Jinxing, also raised a number of blade profile of the specific description of the formula, from The blade profile obtained in each flow line is smooth, in order Screw pumpsto ensure the smoothness of the surface of the stream, but also the smoothness of further examination. In order to meet the needs of CNC machining, now leaves the surface smoothness requirements are high, the impeller can be designed by CNC machining accuracy and fit. Shu-Liang Cao and other current iteration method using axial flow, obtained under the axial flow blade axial bone surface drift-solving and calculation of surface space for cross flow lines, that is, blade bone line, and then apply the leaf-by-point integration drawing of the design obtained by oblique flow pump impeller and diffuser blade surface smooth, suitable for CNC machining. 3.4.2, the shape of axial map In the design of oblique flow pump impeller and guide vane axial shape, usually based on experience or existing models to determine. In the early design, the impeller and guide vane for a short distance between the impeller and guide vane import export side edge in the axis parallel to the projection surface. But now the design is that the increased export side and the guide vane impeller side of the distance of imports is beneficial. Import and export side of the impeller design usually follows the following principles: the import side wheel side protrusion to advance to the flow into the impeller torque applied, reducing the relative velocity of flow, improve the cavitation performance; increased wheel-type flanking dense cascades degrees, so that the flow pattern within the impeller is more stable to prevent the return of non-design conditions to avoid the secondary. Tsuzuki velocity moment method with controlled re-design the shaft surface map of the import side, compared with the conventional design results meet the above requirements. Redesign the results of the elimination of the saddle, better than before to improve performance. To analyze the axial map of the properties, such Saitoh, compared to 330 of the ramp speed of the pump flow was calculated and the internal and external flow characteristics of experimental research findings, changes in axial curvature of the smaller plans, the better the internal flow efficiency higher, but the maximum efficiency point to the large flow direction of migration. 3.4.3, blade angle Xi-jie of the blade angle on performance, and the corresponding statistical formula. Usually export blade angle calculated by the rate of flow angle of the triangle are. One element theory of traditional design, the blade angle along the flow lines change from import to export is monotonous, that the second derivative does not exist 0 value. However, according to the design obtained by Inverse Solution changes of blade angle is different, as shown in Figure 4 for the Sakurai design specific speed mixed flow pump 637 of the impeller hub Department blade angle curve. This variation is obviously different with the traditional design, blade angle in the export increases and then decreases before the purpose is to satisfy the Kutta condition. However, in the flow line to determine the optimal blade angle changes of the current can not be obtained directly in the design stage. 3.4.4, mixed flow pump impeller clearance of flange Impeller pump wheel rim Self-priming pumps clearance will affect the volume loss, thus affecting the performance of the pump. Han-Xin Qian, who studied the oblique flow pump flange gap size on the performance of different. As the gap increases, the efficient and effective at the same time span decreases as leaves, head and power is down. From the efficiency point of view, the smaller the gap the better. From the processing perspective, the smaller the gap the more difficult to manufacture. So the design should be smaller under the specific conditions of the gap as far as possible to take in order to improve the efficiency of the pump. As the impeller blades of the face and back of the pressure difference exists, resulting in the impeller clearance wheel rim will have space jet, thus affecting the flow pattern near the rim. The original and the male establishment for such clearance flow simplified mathematical model, Zhang Spring Festival Gala of the model was developed and used to solve mixed flow pump flange clearance flow, the study found not only leaves space within the jet face and the back of the pressure difference , also with the blade speed and blade angle circumference is closely related to space jet will cause energy loss can not be ignored. In addition, the pump impeller inlet flow channel type on the flow state also has some effect, oblique flow pump to improve the flow of imports, import requirements and the suction pump pool wall a certain distance, and sometimes even increase in the pump inlet diversion pump installed components to meet the requirements of the flow state. 4, the internal flow of mixed flow pump With the centrifugal and axial flow study, the internal flow field analysis becomes oblique flow pump to improve the performance of one of the means. Internal flow field of the study are numerical and experimental studies of two ways. Now commercial software applications to solve the external oblique flow pump characteristic curve has reached a high accuracy, especially in the design condition, the calculation error of efficiency and lift up to 1.5%. Usually there is no front cover oblique flow pump, it is an open structure, so internal oblique flow pump flow test of visual comparison easy. The most common currently used method is the simplest method is to film, but the film method can only be observed over parts of the wall of the flow stream. PIV is to analyze the flow field vane pump more effective visual equipment, Miyabe oblique flow pump in order to analyze the causes of saddle-shaped curve, with inclined flow PIV technique flow inside the pump were studied and found that the mixed flow pump internal flow Chemical pumpsstall the process of occurrence and development of the initial mixed flow pump performance curve of the hump of the causes were analyzed. 5, Conclusion (1) summarizes and analyzes the structural characteristics of mixed flow pump and energy characteristics. Oblique flow pump because there saddle-shaped curve complex, but is certain that with the axial plane graph design, import blade angle design has a relationship; (2) existing research shows that, in addition to high specific speed mixed flow pump, the design by controlling the velocity moment can effectively eliminate the saddle-shaped curve of oblique flow pump. External characteristics of oblique flow pump blade surface load distribution and the velocity distribution closely related to the moment. But how best to control the velocity moment is still uncertain; (3) oblique flow pump design and mapping of the technical requirements to meet the NC machining and rapid prototyping of requirements; (4) the calculation of internal flow field of oblique flow pump performance is an important means. Usually oblique flow pump impeller is open, so its easier to visualize experimental research carried out.

原文来源：http://www.1huagongbeng.com/

2010-09-03 08:16

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