矢量推力模拟加载及测试校准技术研究

航空发动机推力矢量技术是目前国际上的研究热点,为了适应矢量推力发动机的试车试验,国内部分主机场所已经研制或正在研制发动机矢量推力试车台,而如何对矢量推力进行准确的测试及校准一直是难点。本文提出了利用液压加载装置配合不同角度楔形块实现标准矢量力加载的方法,为了验证设计方案的可行性,设计搭建了一套简易的矢量推力模拟加载及测试装置,通过试验给出了测试的误差及存在的问题,为进一步准确测试矢量推力提供了依据。     

发动机稳定性试验研究VXI总线测试系统

发动机稳定性试验研究VXI总线测试系统是针对涡扇／涡喷发动机进行流场畸变试验以及气动稳定性试验研究装置而开发的测试系统，达到了国内先进水平，本文介绍了该系统的功能，技术指标，系统组成，工作原理和软件设计等。     

一种汽车发动机台架测试流量计计量性能监控方案

汽车发动机进气流量测量是发动机台架测试的重要项目,其测量结果直接影响排放的结果.文章制定了一种针对汽车发动机台架测试流量计计量性能监控的方案.该方案研制了专门的核查和修正装置,通过内部核查、外部检定和二次修正相结合的方式,对流量计的计量性能实施监控.当流量计的计量性能出现偏离时,通过二次修正模块对流量计进行修正,使其满...     

微波间隙测量系统研究

针对航空发动机恶劣的现场测试环境,分析了基于微波法进行间隙测量的优点,并描述了微波间隙测试系统的组成和采用微波相位法进行间隙测量的原理,最后,通过对微波叶尖间隙测量系统进行的实验验证,证实了测量系统的有效性,同时分析了测量中的主要影响因素,有助于航空发动机实际测试的应用。     

发动机冷却风扇的振动测试

本文叙述了康明斯公司500kW发动机冷却风扇的振动测试方法,介绍了测试用的试验装置和仪器仪表,并对测试结果进行了分析.叙述的方法将适用于所有的发动机冷却风扇的振动测试.     

航空发动机室内试车台推力测量及其溯源体系分析

航空发动机推力测量相关影响参数的准确获取是保障台架推力测试准确性的前提。本文通过梳理室内试车台架推力附加阻力气动修正方法中所用到的关键试验参数、航空发动机试验与推力测量相关的常见控制参数、测量工具以及溯源标准及要求,最终形成相对完整的溯源体系,为实际试车工况下发动机推力测量校准技术的研究提供了借鉴。     

发动机热机应力测试中的温度补偿技术研究

从发动机热机应力测试的实际需求出发,分析了温度补偿技术对于提高应力测量精度的必要性.系统论述了传统电阻应变片和新型光纤光栅传感器两种应力测量方法的多种温度补偿方案,并探讨了不同温度补偿方法在实际发动机热机应力测试中的可操作性.     

航空发动机测试系统校准

综述了航空发动机测试系统校准工作的现状.根据航空发动机测试系统特点,对航空发动机测试系统校准需求和需要解决的问题进行了分析,并根据目前航空发动机测试系统校准状况,提出了校准解决方案.     

车用燃料电池发动机试验台

整个燃料电池发动机试验台以目标燃料电池车辆动力系统为参照设计,包括负载系统、燃料系统、控制系统和数据采集系统,通过数字化的CAN网络交互各部件的运行信息。根据车辆运行要求,借鉴内燃发动机测试规范,初步设计了一种车用燃料电池发动机的试验工况,并对车用燃料电池发动机进行了测试。测试结果表明,整个试验台对车用燃料电池发动机评估发挥了重要作用,而且有助于燃料电池发动机性能的提高,特别是电磁兼容性。     

汽车发动机冷却水泵性能测试系统设计

设计了汽车发动机冷却水泵性能测试系统,介绍了测试系统硬件组成,测试软件设计,测试项目设置.该系统采用先进的传感器及计算机测控技术,系统软件采用LabVIEW软件平台开发,可对汽车发动机冷却水泵进行多项性能测试.该系统操作方便,测试过程自动化程度高,测试精度好.     

A comparison of the emissions of gasoline–ethanol fuel and compressed natural gas fuel used in vehicles with spark ignition engine in Rio de Janeiro: Brazil

Clean Technologies and Environmental Policy - A comparison of the emissions of gasoline–ethanol fuel and compressed natural gas (CNG) fuel used in vehicles with spark ignition engine was...     

The performance analysis and design optimization of fuel temperature control for the injection combustion engine

The purpose of the paper is to analyze the performance and design optimization of fuel temperature control in the injection combustion engine. There is a fuel temperature control device designed between the injection and fuel pump to cool down or warm up the fuel. Thermoelectric module (TEC) chips are applied in the device to absorb or dissipate heat from the fuel. There are several results relating exhaust emission and engine output performance to fuel temperature in this paper to display the optimization of fuel temperature for the injection engine. The experimental results indicate that increasing fuel temperature will result in an increase in CO, HC, and in a decrease in NO_x. Increasing the fuel temperature may affect the fuel consumption and engine output for a gasoline engine at different A/F (air to fuel) ratios. With enhanced understanding and analyses, the effects of fuel temperature on engine performance, fuel consumption and emissions can be taken into account in engine design and evaluation.     

汽油机燃用轻油基燃料的缸内过程参数分析

介绍作开发的一种汽油机用新型燃料,为检验其品质,对发动机缺内过程参数进行了全面测试分析。结果表明：汽油机燃用轻油基混合燃料时无爆震,动力性稍低于燃用汽油,缺内过程参数标准偏差明显低于燃用汽油。这充分说明,所开发的轻油基混合燃料品质优良,适于汽油机使用。     

Effect of oxy-hydrogen blending with gasoline on vehicle performance parameters and optimization using response surface methodology

ABSTRACT

Rapid decline in fossil fuel reservoirs has attracted researchers to use a variety of fuel blends in Spark ignition (SI) and Compression ignition (CI) engines demonstrating similar performance and lower emissions. Oxy-hydrogen gas obtained through electrolysis has been successfully tested for this use. This paper presents a two wheeler chassis dynamometer based study of a two wheeler loaded with newly developed single cylinder variable compression ratio (VCR) engine utilizing different blends of gasoline and oxy-hydrogen gas. Variation in fuel average performance (FAP), wheel power (WP) and acceleration performance (AP) due to oxy-hydrogen blending with gasoline is studied and compared with neat gasoline at five different gears. Further multi objective optimization of FAP and WP is carried out using response surface methodology (RSM). Regression models are postulated for predicting FAP and WP at different levels of compression ratio (CR) and oxy-hydrogen gasoline blends. Interaction between CR and oxy-hydrogen-gasoline blending is also studied and discussed. Modification carried out on an engine improves vehicle performance parameters and oxy-hydrogen gasoline blending further enhances the improvements. Maximum FAP and WP in top gear is obtained at highest CR of 11.57:1 and a oxy-hydrogen gasoline blend with 112.558 ml/min flow rate of oxy-hydrogen gas.     

Emission reduction on ethanol–gasoline blend using cerium oxide nanoparticles as fuel additive

In this study, the effect of ethanol–gasoline blend with cerium oxide nanoparticles as additive on a Tata Nano twin–cylinder SI engine was investigated. In this work, the combustion, performance and emission tests were conducted. The experiment fuels were prepared using 99.9% pure ethanol and gasoline with cerium oxide nanoparticles. The volumetric percentages of ethanol–gasoline blends with cerium oxide nanoparticles additive are in the ratio of E30, E40 and E50. These represent the ratios of ethanol amount in the total blend and the rest of gasoline. Additionally, 100?mg, 150?mg and 200?mg cerium oxide nanoparticles additive are mixed to E30, E40 and E50, respectively. The venture of this investigation was to reformulate the fuel to utilize the cerium oxide nanoparticles with ethanol and gasoline blend to develop the fuel’s performance and to decrease the pollution from the engine. The experimental results expose an increase in brake thermal efficiency for the nanoparticles blends. In the emission test CO, CO₂, HC and NOx are noticeably reduced, and O₂ increased for all the blends. In combustion analyses, the cylinder pressure is higher for nanoparticles blends, when compared to that of the sole fuel.     

A High-Efficiency Two-Stroke Engine Concept: The Boosted Uniflow Scavenged Direct-Injection Gasoline (BUSDIG) Engine with Air Hybrid Operation

A novel two-stroke boosted uniflow scavenged direct-injection gasoline (BUSDIG) engine has been proposed and designed in order to achieve aggressive engine downsizing and down-speeding for higher engine performance and efficiency. In this paper, the design and development of the BUSDIG engine are outlined discussed and the key findings are summarized to highlight the progress of the development of the proposed two-stroke BUSDIG engine. In order to maximize the scavenging performance and produce sufficient in-cylinder flow motions for the fuel/air mixing process in the two-stroke BUSDIG engine, the engine bore/stroke ratio, intake scavenge port angles, and intake plenum design were optimized by three-dimensional (3D) computational fluid dynamics (CFD) simulations. The effects of the opening profiles of the scavenge ports and exhaust valves on controlling the scavenging process were also investigated. In order to achieve optimal in-cylinder fuel stratification, the mixture-formation processes by different injection strategies were studied by using CFD simulations with a calibrated Reitz–Diwakar breakup model. Based on the optimal design of the BUSDIG engine, one-dimensional (1D) engine simulations were performed in Ricardo WAVE. The results showed that a maximum brake thermal efficiency of 47.2% can be achieved for the two-stroke BUSDIG engine with lean combustion and water injection. A peak brake toque of 379 N·m and a peak brake power density of 112 kW·L⁻¹ were achieved at 1600 and 4000 r·min⁻¹, respectively, in the BUSDIG engine with the stoichiometric condition.     

Laser ignition in internal-combustion engines: Sparkless initiation

Laser ignition has been implemented in a single-cylinder internal combustion engine fueled by gasoline. Indicator diagrams (cylinder pressure versus crank angle) were obtained for laser ignition with nano- and microsecond pulses of an Nd:YAG laser. The maximum power of microsecond pulses was below critical for spark initiation, while the radiation wavelength was outside the spectral range of optical absorption by hydrocarbon fuels. Apparently, the ignition starts due to radiation absorption by the oil residues or carbon deposit in the combustion chamber, so that the ability of engine to operate is retained. This initiation of spark-free ignition shows the possibility of using compact semiconductor quantum-cascade lasers operating at wavelengths of about 3.4 μm (for which the optical absorption by fuel mixtures is high) in ignition systems of internal combustion engines.     

Safety measures associated with the operation of engines on various alternative fuels

This paper reviews the safety of the operation of conventional engines on various alternative fuels. It is shown that methane in the form of compressed natural gas (CNG) is a safer engine fuel than common gasoline or other alternative fuels such as propane or hydrogen. The paper also describes the safety procedures adopted in the design and operation of a conventional laboratory engine on rich mixtures of methane and oxygen enriched air for hydrogen and synthesis gas (i.e. CO + H₂) production.     

基于多传感器融合的电喷汽油机过渡工况进气流速预测模型

为了解决车用汽油发动机工作在过渡工况时,进气状态变化大,空气流量传感器的滞后响应严重影响空燃比控制精度的问题,提出了一种基于多传感器融合的过渡工况进气流速的预测模型,建立了过渡工况进气流速预测的径向基神经网络的拓朴结构,以HL495Q电喷汽油机加减速工况实验数据进行离线训练,仿真结果表明该预测模型能准确地预测过渡工况的空气进气流速,为精确及时地测试汽油机空气进气流量提供了一种新的方法.     

Distinctive features of operation of an internal combustion engine running on hydrogen-containing fuels

Experimental investigations have been carried out on an internal combustion engine with hydrogen added to the hydrocarbon fuel, i.e., gasoline. The possibility of improving the energy and environmental indices in the case of hydrogen feed to the engine’s air path has been shown. It has been established that increase in the fraction of hydrogen in the fuel mixture causes the operating process of the engine to improve, with the result that the flow rate of gasoline as a function of the H₂ fraction decreases by nearly 70%. Considerable reduction in the content of CO, CO₂, and CH (of approximately 5–60% depending on the amount of the added H₂) is observed. However, adding hydrogen to the fuel-air mixture leads to an increase in the content of nitric oxides in the combustion products because of the growth in the velocity of propagation of the flame and increase in the combustion temperature.