高原运行柴油机增压技术应用综述

针对高原环境涡轮增压柴油机功率下降、油耗上升、热负荷升高的问题,考虑通过增压系统的改进解决之.在综述了涡轮增压器的重新匹配,涡轮增压器结构改进、补气增压、电动增压、机械增压,二级增压、以及可变增压等技术方案的基础上,以某型特种车辆柴油机为例,分析了各方案的应用情况和总体效果.分析为高原环境涡轮增压器故障维修和通过改造增压系统恢复高原运行柴油机功率提供参考.     

工程机械用涡轮增压柴油机及其排放控制与节能

阐述了工程机械柴油机废气涡轮增压器的作用、结构及工作原理;涡轮增压与排放控制技术;涡轮增压及中冷技术对排放的影响;分析了工程机械用柴油机涡轮增压技术的应用现状和发展趋势。     

一种用于节能赛车的气动增压系统的研发

在节能赛车竞赛中,提高赛车的性能和速度,是一个不断探索和研究的问题。而涡轮增压技术成为了一种重要的技术手段。本文所叙述的气动增压系统是基于节能赛车,重新安置了泵轮能源供给的管路,使得节能车内部空间得到更合理的配置,通过对涡轮增压器的静力学分析、压缩气瓶的静力学分析、涡轮增压器的流体分析,得出所设计的气动增压系统结构合理,满足使用要求,所设计的涡轮增压器的质量流量达到3.7g/s,并且增压效率显著提升。该研究对于推动节能赛车涡轮增压系统的发展和应用有一定的参考和借鉴意义。     

博格华纳由可变截面涡轮增压器向电子涡轮增压器发展

正随着中国汽车产业政策日趋严格的排放法规颁布,发动机必须配置涡轮增压器以到达排放标准,而且消费者选用配有涡轮增压器的汽车,在降低油耗的同时可以增加驾驶乐趣。目前,涡轮增压器在我国乘用车上的渗透率不到30%,而在欧洲,这一比例已经达到了八成以上。据预测,到2019年,中国涡轮增压器市场的总需求将达到60%以上。现在,涡轮增压器的技术趋势就是从普通的废气旁通阀涡轮增压向可变截面和两级增压过渡。其中,博格华纳的     

柴油发动机涡轮增压相关技术分析

涡轮增压技术不仅可以改善柴油发动机的动力性及燃油经济性,还可以减小噪声,提高发动机效率。基于涡轮增压技术的优点,介绍柴油发动机涡轮增压的结构和原理以及几种重要的涡轮增压器,并分析其主要特性,为柴油发动机技术的改进提供参考。     

涡轮增压器排气端智能可变A／R值机构介绍

涡轮增压器排气端智能可变A／R值机构,是由发动机电喷系统通过发动机工作状态,对涡轮增压器排气道上的节气门体开度进行智能调节,从而智能调节A／R值。该机构解决传统涡轮增压器因A／R值固定,发动机低转速涡轮滞后或者高转速涡轮增压不足的技术问题,使涡轮增压发动机的全转速域达到最优的工作效率。     

某型柴油机与VGT增压器的匹配计算研究

发动机与涡轮增压器的匹配是增压技术的重要研究内容。普通涡轮增压器与发动机匹配时普遍存在着低速时转矩不足、经济性差等问题。可变几何涡轮增压器(VGT)是解决增压柴油机低工况和瞬态响应慢的重要技术措施。为了分析VGT对某型柴油机性能的影响,基于GT-POWER仿真平台对其进行了建模和仿真研究。结果表明:通过调整VGT涡轮喷嘴角度可以优化柴油机与VGT的匹配。低工况下,可以有效提高扭矩、增压压力和涡前排气温度,降低燃油消耗率。     

博格华纳推出搭载两个VTG增压器的R2S~涡轮增压系统

<正>博格华纳日前将宝马235 k W柴油发动机的性能提升到了新的高度。这款发动机用于宝马的多个车型中,采用博格华纳的可调两级涡轮增压技术(R2S),通过两个可变截面涡轮增压器(VTG),有效增强发动机动力,实现迅速加速,同时大幅减少排放和油耗。在这一全新应用中,博格华纳的R2S涡轮增压技术将两个电动VTG涡轮增压器串联起来,其中尺寸较小的高压涡轮增压     

涡轮增压器的流动模拟方法综述

随着人们对节能环保问题的日渐关注,增压技术特别是涡轮增压器在内燃机上的应用也越来越普遍,而研究涡轮增压器内的流动对设计高效率的增压器至关重要。综合国内外研究涡轮增压器的流动模拟方法,总结和概括了在模拟增压器内部流动方面的一般方法和普遍规律,对充分了解增压器内的流动过程并改善其工作性能具有一定意义。     

汽车涡轮增压器产线中取气管压入工位的研究

涡轮增压技术已经非常普及,随着汽车行业的快速发展,汽车涡轮增压器技术也得到了快速的推广。汽车涡轮增压器经常处于高速、高温下工作,其生产工艺要求非常高。本文主要针对某汽车涡轮增压器自动化生产线中的取气管压入工位做了研究,详细介绍了此工位的工作流程及主要部件的功能。     

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...     

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.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

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....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.