应用长管—微机法测量柴油机喷油规律的研究

本文介绍用长管—微机法测量柴油机喷油规律的原理和装置,给出并分析了对6130Q柴油机供油系统的测量结果。     

喷嘴参数对柴油机喷油规律与性能的影响

采用广安博之(Hiroyasu)等准维模型,建立高原运行柴油机工作过程模型;基于一维非定常可压缩理论建立柴油机喷射系统模型,二者耦合计算高原环境喷油器主要结构参数对柴油机实际运行时的喷油规律、燃烧特性和输出性能的影响.台架试验验证了模型的可信性.结果表明:喷孔数和喷孔直径对喷油规律影响最为敏感,喷孔夹角对喷油规律影响微弱.在海拔4 000m时,针对该型柴油机,喷孔面积存在一个最优区间,在该区间给出了功率变化率和喷孔面积的关系式.在燃烧室结构和供油系统参数不变的情况下,当喷孔面积减小为原喷孔的25%～60%时,柴油机功率最大提升8.5%;油耗最大下降8.8%,排气温度下降35℃以上.但是缸内温度明显上升,NOx排放恶化.研究为通过优化喷油器参数改善高原运行柴油机燃烧和性能提供了参考.     

利用船舶主机余热制冰的实验探究

基于吸收式制冰机,利用船舶柴油机尾气进行了尾气余热制冰实验。考察了制冰机对柴油机工作的影响及柴油机功率、环境温度等因素对制冰量的影响,得到大量实验结果,通过对实验结果进行分析,得出了柴油机尾气余热制冷特点及规律。     

基于YC2105小型农用柴油机电控调速器控制策略研究

随着柴油机技术的发展,柴油机电子调速的控制研究越来越多,本文针对YC2105柴油机调速器在农用发动机上应用的缺陷即难以实现较为复杂的调节规律和控制功能,无法满足降低油耗、提高调节精度、减少有害排放等要求,研究了YC2105柴油机电控调速器控制策略,设计了柴油机基本喷油量、起动喷油量及怠速条件三种情况下的电控调速器控制策略。为下步实现控制模型的建立打下良好基础。     

应用长管—微机法测量柴油机喷油规律的研究

本文介绍用长管－微机法测量柴油机喷油规律的原理和装置，给出并分析了对６１３０Ｑ柴油机供油系统的测量结果。     

柴油机气缸的磨损形式

气缸是柴油机的关键零部件,其寿命的长短影响到柴油机的寿命,进而会影响到柴油机的动力性、经济性,而磨损又是造成气缸损坏的主要原因。因此,弄清柴油机气缸磨损的原因,掌握气缸的磨损规律,可以帮助我们正确地使用柴油机,延长其使用寿命,提高机械设备的经济效益。 气缸的磨损是由气缸套和活塞环之间的摩擦造成的。它们之间的磨损     

柴油机配气相位的分析与优化

柴油机配气相位的分析优化对柴油机性能有重要影响。首先通过AVL BOOST软件建立了柴油机的工作过程仿真模型,并运用台架试验数据对仿真模型进行了验证。接着分析了不同的配气相位对柴油机性能的影响,得出在不同转速下配气相位对柴油机功率、扭矩、充气效率及有效燃料消耗率的影响规律,从而得到了最佳的配气相位值,并将优化后的柴油机性能与原机进行了比较。仿真结果表明,优化后的配气相位使柴油机的动力性和经济性都有一定提高。     

刚度匹配对柴油机机体组载荷响应影响

以某种高强化机型柴油机的机体-气缸套-气缸垫-气缸盖组合结构为主要研究对象,采用量纲分析和有限元数值模拟的分析手段,给出了一种研究柴油机机体组中各部件间整体刚度变化对其载荷响应影响规律的分析方法,获得了柴油机机体组静力学载荷响应的主要控制参数,并从整体刚度层面以气缸盖和机体之间的刚度匹配为例,给出了两者弹性模量比对上述机体组应力、气缸套变形以及气缸垫密封压力等载荷相应的影响规律。     

高海拔柴油机燃烧过程研究综述

通过对柴油机高海拔燃烧过程的研究,可以探索高原环境对柴油机性能影响的机理,为柴油机高原性能提升提供理论依据。本文综述了国内外柴油机高海拔燃烧过程研究的总体情况,总结了高海拔环境对柴油机燃烧过程的影响规律,分析了提升柴油机高海拔燃烧特性的先进技术及策略。     

柴油机常见噪声的诊断方法

<正>1.柴油机常见异常响声的诊断(1)整机振抖响声柴油机启动后产生没有规律的振抖响声,且随着转速的增高而加剧。主要原因:柴油机支承螺栓松动或悬置断裂;柴油机悬置位置不当,致使曲轴与第一节传动轴不同轴;柴油机悬置缓冲件损坏等。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....