高压比大推力离心压气机流场分析

基于CFD设计了一款转速60000 r/min、压比7、流量1.5 kg/s的大推力压气机,采用spalart-allmaras湍流模型和Navier-Stokes方程组对压气机叶轮内的气体流动及其工作范围进行了数值模拟,分析了60000 r/min转速时最高效率点附近的相对马赫数和流线云图,开展了非设计转速下的流场分析,计算了不同转速下的工况,研究了设计转速下叶轮入口处激波和射流尾迹的流动情况。研究结果表明：设计工况条件下,等熵效率为84.25%,压比为8.167;转速从48000 r/min到54000 r/min时,等熵效率提高,流场改善,气动损失减小;压气机转速从60000 r/min增加到72000 r/min时,压气机等熵效率、气动损失减小、稳定工作范围收窄;高压叶轮的主要气动损失为叶片表面的激波损失、叶尖间隙损失、二次流损失及吸力面尾缘的低能流体。     

基于ANSYS的大型数控机床大扭矩、大功率B摆角铣头模态分析

论述了大型、精密、高档机床在未来制造业发展中的重要性;对不同结构的摆角铣头作了简单介绍.在Pro/E系统中对B摆角铣头进行三维实体造型,此B摆角铣头用于铣削自由曲面.利用实体模型,在有限元分析系统中建立铣头的动力学分析模型,并给出了实体模型建立时应注意的问题.用ANSYS软件分析了铣头的固有特性.     

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。     

活塞压缩机的优化设计及试验研究

论述了余隙容积对压缩机性能的影响.以全QD系列全封闭活塞压缩机为例,通过减少其阀板厚度的方法减少余隙容积,提高压缩机的制冷量,对压缩机气阀进行优化设计.实验表明：该方法对指导压缩机气阀的优化设计是可靠的、有效的.     

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.     

举升机构优化设计

采用内点惩罚函数法对举升机构的关键件，气缸的两端支点的位置参数进行了优化设计。优化后的举升机构，不仅气缸行程最短，而且，整个机构的高度也比要求的大大降低，经实际使用效果很好。     

高压离心式氧压机的结构强度分析及优化

离心式氧气压缩机正常工作状态时需承载高内压栽荷,高强度承压机壳的设计是其结构设计问题中的难点.文中完成了三万等级离心氧压机在高内压条件下的仿真分析,考虑了上下机壳之间的接触问题和螺栓预紧力对结构强度的影响,重点计算了氧压机机壳、底座装配体的强度,并对氧压机整机进行了必要的模态分析.同时,完成了在水压试验时的氧压机上机壳的内压分析,得到了氧压机机壳可以承受的极限水压力.在满足设计、制造的安全性和合理性前提下,对机壳结构进行了优化,改善了机壳的应力分布,并在制造过程中节省超过7%的材料.     

Tip clearance effect on through-flow and performance of a centrifugal compressor

Numerical simulations have been performed to investigate tip clearance effect on through-flow and performance of a centrifugal compressor which has the same configuration of impeller with six different tip clearances. Secondary flow and loss distribution have been surveyed to understand the flow mechanism due to the tip clearance. Tip leakage flow strongly interacts with mainstream flow and considerably changes the secondary flow and the loss distribution inside the impeller passage. A method has been described to quantitatively estimate the tip clearance effect on the performance drop and the efficiency drop. The tip clearance has caused specific work reduction and additional entropy generation. The former, which is called inviscid loss, is independent of any internal loss and the latter, which is called viscous loss, is dependent on every loss in the flow passage. Two components equally affected the performance drop as the tip clearances were small, while the efficiency drop was influenced by the viscous component alone. The additional entropy generation was modeled with all the kinetic energy of the tip leakage flow. Therefore, the present paper can provide how to quantitatively estimate the tip clearance effect on the performance and efficiency.     

大型离心式压缩机铸造机壳的静态有限元分析

为了给某型号离心式压缩机铸造机壳改进设计提供理论依据,对其进行了静态有限元分析,并针对机壳模型特征繁多、曲面复杂,网格划分不易,致使有限元分析不能进行的问题提出了具体解决方法。结果表明了该方法的可行性,可应用于其它铸造机壳或焊接机壳的静态有限元分析中,为分析节省时间,提高效率。     

DHP45型离心压缩机振动原因分析与改进

通过对可能产生离心压缩机振动异常的情况进行的分析,找到了造成DHP45型离心压缩机振动异常的原因.利用更换可倾瓦轴承的办法,解决了离心空气压缩机的振动问题,达到了稳定运行的目的.     

薄壁零件冲压机构优化设计

薄壁零件在冲制过程中要求匀速拉延成形。在对机构运动分析的基础上 ,以执行构件在导程中的最大速度与平均速度的比值描述工作段滑块接近等速运动的程度 ,并以此为目标函数 ,在MATLAB环境下进行机构优化设计。     

离心空压机喘振与控制

由于离心式空压机结构简单,排气量大,效率高,目前广泛应用于冶金、化工以及空分等行业。但离心式空压机在运行过程中,对气体的压力、流量以及温度变化较为敏感,容易发生"喘振"现象。离心空压机喘振具有较大的危害性,是造成空压机损坏的主要原因之一。因此,研究和预防喘振的发生,弄清和掌握喘振的机理,采取有效控制措施避免喘振的发生是离心空压机控制中的重要任务。