离心泵叶轮抗汽蚀优化设计

针对循环水系统离心泵的汽蚀问题对叶轮进行优化,通过选择适当的叶轮折引直径,改变叶轮入口角度来改善泵的吸入性能及改变叶轮的制造工艺和选择抗汽蚀性能好的双相不锈钢,较好解决了循环水泵叶轮汽蚀问题并设计制造焊接式叶轮.     

螺旋式离心泵叶轮动平衡问题的优化设计

叙述了针对现有处理螺旋式离心泵叶轮动平衡问题所存在的不足，通过借助于三维CAD手段对叶轮进行优化设计，较好地解决了动平衡的问题，实现了既可减少叶轮的加工去重量，降低制作成本，改善泵加工质量，又可提高泵的工作效率，真正地达到以低的消耗．生产出高质、节能的螺旋式离心泵产品。     

离心压缩机叶轮的形状优化设计

提出一种新的优化方法离心叶轮的形状优化问题，即在遗传算法中加入自适应算子调节个体变异概率，来保证搜索的全局性和种群的多样性。并在寻优过程中加入生物生长来加快其寻优速度。最后，采用遗传算法和改进的遗传算法－生物生长法两种方法，对叶轮进行优化设计。计算结果表明改进的遗传算法－生物生长法，在较少的优化时间得到最优解。     

螺旋离心式叶轮的设计新方法

介绍了一种用螺旋方程绘制螺旋叶轮的方法，解决了用常规绘型方法无法进行螺旋叶轮水力设计的问题。     

离心式压缩机叶轮转子抛光的节能原理及应用

针对大型钢铁企业制氧厂用DH－71型离心式空压机进行节能技术研究，论述对压缩机叶轮转子进行打磨抛光的节能原理及工艺方法。     

采用流固耦合的混砂车搅拌叶轮应力分析

叶轮是混砂车搅拌系统的核心部件,叶轮的强度、刚度对搅拌系统的正常使用起着重要的作用.叶轮在搅拌工作中承受流体对叶片的作用力、离心力及重力等载荷作用,为了准确得到各载荷对叶轮的影响,采用流固耦合分析方法对叶轮进行数值模拟分析.分析结果表明:上叶轮根部应力值最大,上叶轮端部位移最大,流体作用力为影响叶轮强度的主要因素,这为叶轮的强度校核提供了可靠依据.     

浅析整体齿轮式离心压缩机设计

离心压缩机属于技术门槛高,且需整合多学科关键技术的透平机械。本文主要描述了整体齿轮式离心压缩机的设计理念、流程及关键气动参数的取值分析,并利用商用软件结合工程实例阐述单级整体齿轮式离心压缩机主要气动部件的设计流程、参数输出及实物机的验证。     

Sliding thrust bearings in a centrifugal compressor with a semiclosed impeller

The equipment for dynamic tests of sliding thrust bearings is considered. The test data are analyzed for a thrust bearing with motionless pads in a centrifugal compressor with a semiclosed impeller in pumping mode.     

基于Workbench整体叶轮流固耦合强度分析

作为许多动力机械的核心部件的叶轮,其强度及可靠性的问题日渐突出。叶轮工作时,流体力和高速旋转时的离心力为其主要载荷。基于Workbench软件对整体叶轮的内部流场和工作压力分布进行数值模拟;使用ANSYS CFX进行复杂几何形状叶轮的流体动力分析,得到了整体叶轮的流场和工作压力场及流体载荷在叶轮内部产生的等效应力分布图,并耦合了旋转离心载荷等,研究了在高压工况情况下,叶轮的载荷组成和流固耦合下的叶轮强度。     

基于SolidWorks的化工离心泵叶轮模具设计

针对传统离心泵叶轮设计步骤繁琐的不足,提出了基于SolidWorks的三维参数化离心泵叶轮注塑模设计方法。简单介绍了SolidWorks的主要功能模块及离心泵叶轮模具设计的流程,详细阐述了离心泵叶轮模具设计的步骤。设计中,叶轮采用尼龙6/10材料,其拔模斜度为1.5°,收缩率为1%。通过对模具各零部件的造型与实时修改,实现了离心泵叶轮模具的参数化设计,并完成了模具的虚拟装配及加工出详图的快速输出。本方法对工程设计具有一定的实用价值。     

新型离心叶片设计方法研究

从控制载荷分布的思想出发,以叶片的几何角和半径的关系作为加载规律,提出了加载规律的参数化控制思想,发展了控制叶片加载规律的设计方法,使加载规律的概念更加明确、实施方法更加简单有效。为了研究不同加载规律对叶片性能的影响,首先设计了几种具有代表性的加载规律,对比各种加载规律,结果表明:中间加载规律使得叶片对气流的加功量主要集中在叶片的中部,为叶片的进、出口创造了良好的流动条件,气流比较稳定,流动损失较少,滑移系数较大,保证有足够的压比和较高的效率,抗喘振能力较强,是比较理想的加功方式。     

高速离心压气机变工况模拟及叶轮叶片优化研究

离心压气机作为增压器核心部件,对增压器性能有决定性影响.利用CFD模拟软件ANSyS-Fluent,以某型涡轮增压器核心部件—压气机为研究对象,进行了设计转速下的变工况数值模拟,得到了不同质量流量下离心压气机的内流场数据,通过与实验数据进行对比,验证了仿真模拟的正确性.在额定工况下,对后弯叶轮叶片出口段沿旋转方向不同倾...     

Dynamic behavior of valve system in linear compressor based on fluid-structure interaction

In refrigerator designs, the linear compressor is preferable to the recipro-type compressor, due to its higher energy efficiency. The linear compressor’s valve system, however, causes significant noise, not only in the steady state but also in the transient state. To accurately predict the behavior of the suction and discharge valve system in both states, the interaction between the fluid flowing through the valves and the structural deformation of the valves needs to be understood. In the present study, the steady-state behaviors of the valve system were numerically analyzed using ADINA software, which takes fluid-structure interaction (FSI) into account. This computational analysis thereafter was experimentally validated. The effects of a pre-load of the conical compression spring on the dynamic characteristics of the valve system also were analyzed.     

离心式固液两相流泵的叶轮设计

阐述离心式固液两相流泵的叶轮设计的方法,分析了基于不同两相流理论的叶轮参数的选择方法,指出叶轮型线设计是固液两相流泵设计的重要环节,并阐述了基于边界层理论的叶片型线设计方法。     

旋转式秸秆压实机的优化设计

为提高秸秆压块的生产率,设计了一种旋转式秸秆压实机,并介绍了其工作原理。这种压实机的特点是预压、压实和推出三个阶段同时进行,大大缩短了秸秆成型周期。在三个阶段中,用时最长的那个阶段决定了秸秆压块成型周期,所以建立了生产一定质量的秸秆压块所用的时间最小优化的数学模型。最后,针对仿真实例进行目标优化,得到一种功率分配优化方案。     

Numerical simulation of fluid-structure interaction in a stirred vessel equipped with an anchor impeller

A coupling algorithm is used to compute the equilibrium of a flexible anchor impeller in a stirred vessel. This coupling algorithm is based on a partitioned approach, which consists of three relatively independent modules: the computational fluid dynamics (CFD), the computational structure dynamics (CSD) and the interface. In the CFD module, the Euler formulation was used to account for the moving boundary. In the CSD module, the updated Lagrangian formulation for solving the motion of non-linear structure was used and a static study was adopted. In the interface module, an exchange of the forces and displacements was allowed. The numerical results, such as the velocity field, the turbulent kinetic energy, its dissipation rate, the turbulent viscosity and the mechanical deformation, have been presented. Particularly, we are interested in the study of the static behavior of the anchor impeller and the evolution of the displacement field of the arms during various iterations of our coupling algorithm. Accordingly, if the anchor impeller undergoes a deformation due to the flexion of the arms of the anchor impeller, the numerical results changes slightly from iteration to another. At the end of certain iteration, the anchor impeller becomes deformed and the velocity field is preserved. These results confirm that the fluid has a significant effect on the deformation of the arms of the anchor impeller during mixing depending on the velocity of the anchor impeller and the fluid flow. The numerical results were validated by a comparison with literature data.     

Cavitation optimization for a centrifugal pump impeller by using orthogonal design of experiment

Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitation performance. Therefore, it is necessary to find an appropriate solution to improve cavitation performance with acceptable efficiency. In this paper, to improve the cavitation performance of a centrifugal pump with a vaned diffuser, the influence of impeller geometric parameters on the cavitation of the pump is investigated using the orthogonal design of experiment(DOE) based on computational fluid dynamics. The impeller inlet diameter D_1, inlet incidence angle Δβ, and blade wrap angle φ are selected as the main impeller geometric parameters and the orthogonal experiment of L_9(3*3) is performed. Three-dimensional steady simulations for cavitation are conducted by using constant gas mass fraction model with second-order upwind, and the predicated cavitation performance is validated by laboratory experiment. The optimization results are obtained by the range analysis method to improve cavitation performance without obvious decreasing the efficiency of the centrifugal pump. The internal flow of the pump is analyzed in order to identify the flow behavior that can affect cavitation performance. The results show that D_1 has the greatest influence on the pump cavitation and the final optimized impeller provides better flow distribution at blade leading edge. The final optimized impeller accomplishes better cavitation and hydraulic performance and the NPSHR decreases by 0.63 m compared with the original one. The presented work supplies a feasible route in engineering practice to optimize a centrifugal pump impeller for better cavitation performance.     

Discussion on back-to-back two-stage centrifugal compressor compact design techniques

Design a small flow back-to-back two-stage centrifugal compressor in the aviation turbocharger, the compressor is compact structure, small axial length, light weighted. Stationary parts have a great influence on their overall performance decline. Therefore, the stationary part of the back-to-back two-stage centrifugal compressor should pay full attention to the diffuser, bend, return vane and volute design. Volute also impact downstream return vane, making the flow in circumferential direction is not uniformed, and several blade angle of attack is drastically changed in downstream of the volute with the airflow can not be rotated to required angle. Loading of high-pressure rotor blades change due to non-uniformed of flow in circumferential direction, which makes individual blade load distribution changed, and affected blade passage load decreased to reduce the capability of work, the tip low speed range increases.     

离心式压缩机的轴承

介绍了离心式压缩机轴承的分类及工作原理，分析了常用的径向轴承和止推轴承的几种型式及优缺点，着重对可倾瓦径向轴承、米楔尔止推轴承、金斯伯雷止推轴承的工作原理、结构特点、优缺点及应用进行了分析和总结。