共查询到20条相似文献，搜索用时 31 毫秒
1.
INTRODUCTIONTheinternalcombustionengineisthemostwidelyusedpowermachineryinmodernsociety ,butisalsooneofthebiggestenvironmentalpol lutantsources.Tomeetmoreandmorestringentemissionrequirements,manyadvancedtech niques,suchastheleanburntechnique ,multi valvet… 相似文献
2.
利用AMESim软件建立了春风152MI小型单缸内燃机模型,基于发动机原始数据对发动机模型参数进行了设置,并验证了模型的正确性;利用VVT凸轮移相原理改变模型中进气凸轮相位,研究其扭矩及功率的变化。结果表明：随转速的升高,进气迟闭角越大扭矩越大,功率也越大。 相似文献
3.
This work investigates the effects of exhaust gas recirculation (EGR) and operation parameters including engine speed, equivalence ratio, coolant-out temperature, and intake charge temperature on the basic characteristics of a single-cylinder homogeneous charge compression ignition (HCCI) engine powered with reformulated iso-octane fuels. The running range of iso-octane HCCI engine can be expanded to lower temperature and more load by adding di-tertiary butyl peroxide (DTBP) in the fuel. The combustion timing advances with the increase of DTBP concentrations, coolant temperature and equivalence ratio. The effects of EGR on the combustion and emissions are remarkable when the EGR rate is higher than 25%, and the combustion phase is sharply postponed and the UHC and CO emissions deteriorate. The intake charge temperature has a moderate effect on combustion and emissions when it is lower than 35°C; but the combustion timing advances, the combustion duration shortens, and sometimes it leads to knock combustion when the intake charge temperature increases to above 35°C. 相似文献
4.
Virtual design and performance prediction of a silencing air cleaner used in an I.C. engine intake system 总被引：3，自引：0，他引：3
INTRODUCTION The primary function of an intake system is firstly to efficiently channel fresh air to the engine,and secondly to minimize intake noise emissions.There are a number of current approaches for devel-oping a more realistic method to improve intake sys-tem design.The objectives include more effective silencing performance to meet increasingly severe legislative targets for reduced noise on the one hand,with optimized engine performance and fuel economy accompanied by improvements… 相似文献
5.
INTRODUCTION The use of dimethyl ether (DME) as an alterna-tive fuel appears to be a promising approach for si-multaneously minimizing NOx and soot emissionfrom conventional diesel engines. The lowself-ignition temperature of 508 K and the high oxy-gen content of 34.8 percent (mass fraction) are twomajor factors characterizing low soot and unburnedtotal hydrocarbon (THC) emissions. Since the firstintroduction of the concept by Sorenson and Mik-kelsen (19… 相似文献
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本文介绍了汽油机燃烧过程仿真模拟的类型,建立了汽油机燃烧的准维模型。编制了基于VisualBasic的数值模拟程序,并利用该程序计算了某汽油机的燃烧过程。 相似文献
7.
A new method for the generation of orthogonal body-fitted grids is presented in this paper. The positions of boundary points
in the physical domain are adjusted to obtain orthogonal curvilinear grids without changing the value of ξ and η during the
numerical process. The densities of ξ and η are given in advance. Good results were achieved in the application of this method
on the cooling system of an internal combustion engine and a trail duct. 相似文献
8.
为优化内燃机构造与原理课程的课堂教学效果,结合教学实践经验,从教学内容和教学方法两个方面提出改革思路,改变传统的“教师讲,学生听”的填鸭式教学模式,从而充分调动学生学习的主动性和积极性,使学生在有限的时间内更好地掌握和理解内燃机的相关知识, 相似文献
9.
Jun-yi LIANG Jian-long ZHANG Xi ZHANG Shi-fei YUAN Cheng-liang YIN 《浙江大学学报(A卷英文版)》2013,14(8):535-553
To solve the low power density issue of hybrid electric vehicular batteries, a combination of batteries and ultra- capacitors （UCs） could be a solution. The high power density feature of UCs can improve the performance of battery/UC hybrid energy storage systems （HESSs）. This paper presents a parallel hybrid electric vehicle （HEV） equipped with an internal combus- tion engine and an HESS. An advanced energy management strategy （EMS）, mainly based on fuzzy logic, is proposed to improve the fuel economy of the HEV and the endurance of the HESS. The EMS is capable of determining the ideal distribution of output power among the internal combustion engine, battery, and UC according to the propelling power or regenerative braking power of the vehicle. To validate the effectiveness of the EMS, numerical simulation and experimental validations are carried out. The results indicate that EMS can effectively control the power sources to work within their respective efficient areas. The battery load can be mitigated and prolonged battery life can be expected. The electrical energy consumption in the HESS is reduced by 3.91% compared with that in the battery only system. Fuel consumption of the HEV is reduced by 24.3% compared with that of the same class conventional vehicles under Economic Commission of Europe driving cycle. 相似文献
10.
The flame structure of gasoline engine is complicated and has the characteristic of fractal geometry. A fractal combustion model was used to simulate the engine working cycle. Based on this model, the fractal dimension and laminar flame surface area of turbulent premixed flames were studied under different working conditions. The experimental system mainly includes an optical engine and a set of photography equipment used to shoot the images of turbulent flame of spark-ignition engine. The difference box-counting method was used to process 2D combustion images. In contrast to the experimental results, the computational results show that the fractal combustion model is an effective method of simulating the engine combustion process. The study provides a better understanding for flame structure and its propagation. 相似文献
11.
Three-dimensional transient numerical simulation for gas exchange process in a four-stroke motorcycle engine 总被引：3，自引：0，他引：3
INTRODUCTION In-cylinder flow characteristics during fuel in-jection and subsequent interactions with fuel sprays and combustion are important effect on engine per-formance and exhaust emissions of an engine(Floch et al.,1998;Kim et al.,1999).Four key parameters control the flow field in an engine:the mean flow components,the stability of the mean flow,the tem-poral turbulence evolution during the intake and compression strokes,and the mean velocity near the spark gap at the time of ignit… 相似文献
12.
高国珍 《实验室研究与探索》1999,18(1):51-53,60
在内燃机中,很多参数对性能的影响是相互制约,互有影响的,但以往的试验方法都采用单项试验,不仅试验次数多,周期长,费用大,且要求试验者必须具有较丰富的理论知识和实践经验。通过试验分析,认为正交试验法是一种研究多因素影响结果的软科学的试验方法,它在内燃机燃烧室改进试验中取得了良好的效果。 相似文献
13.
本文对汽油机瞬态工况燃烧特性的研究意义和研究现状进行了概述,介绍了进行瞬态燃烧研究的实验方案,提出了一种研究内燃机瞬态信号的方法——符号时间序列方法。 相似文献
14.
均质压燃（HCCI）能够使发动机同时保持较高的动力性能和燃油经济性,而且能有效降低发动机的NOx和PM排放,是一种克服传统的汽油机和柴油机缺点、集二者优点于一体的新的燃烧模式。由于其突出的优越性已成为目前世界范围发动机领域的研究热点,应用前景广阔,但由于HCCI的燃烧特点以及目前相关技术的约束,使其实用化进程仍存在不少问题。本文对HCCI燃烧方式和过程进行了介绍,详细分析了制约和影响HCCI燃烧方式的关键因素,针对HCCI的特点及其燃烧始点和燃烧过程控制的关键问题,提出了改变空气/燃料混合气特性的可变控制技术解决方案,为HCCI技术的实用化进程提供理论指导,为尽快实施HCCI燃烧方式指出了技术方向。 相似文献
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应用Chemkin化学动力学软件包中的Senkin模块模拟了正庚烷在多孔介质发动机中的燃烧过程．通过修改Senkin程序,结合了Woschni传热模型和多孔介质换热模型,并在正庚烷详细氧化机理中加入氮氧化物的生成机理,将此程序纳入发动机燃烧的零维单区模型．对多种工况参数进行计算,讨论了运行参数对发动机性能的影响．当进气温度、压缩比增大,或过量空气系数降低时,多孔介质发动机着火时刻会明显提前．结果表明：多孔介质对混合气具有预热作用可强化发动机的点火燃烧,多孔介质的初始温度是决定压燃点火的决定性因素． 相似文献
16.
The transverse injection flow field has an important impact on the flowpath design of scramjet engines. At present a combination of the transverse injection scheme and any other flame holder has been widely employed in hypersonic propulsion systems to promote the mixing process between the fuel and the supersonic freestream; combustion efficiency has been improved thereby, as well as engine thrust. Research on mixing techniques for the transverse injection flow field is summarized from four aspects, namely the jet-to-crossflow pressure ratio, the geometric configuration of the injection port, the number of injection ports, and the injection angle. In conclusion, urgent investigations of mixing techniques of the transverse injection flow field are pro- posed, especiaUy data mining in the quantitative analytical results for transverse injection flow field, based on results from multi-objective design optimization theory. 相似文献
17.
In the beach well intake system, heat is transferred from soil to fluid when seawater is filtered through the aquifer, providing higher temperature source water to the seawater source heat pump (SWHP) system in winter. A 3-D coupled seepage and heat transfer model for studying beach well intake system is established by adopting the computer code FLUENT. Numerical results of this model are compared with the experimental results under the same conditions. Based on the experiment-verified coupled model, numerical simulation of the supply water temperature is studied over a heating season. Results show that the minimum temperature of supply water is 275.2 K when this intake system continuously provides seawater with flow rate of 35 m3/h to SWHP. Results also indicate that the supply water temperature is higher than seawater, and that the minimum temperature of supply water lags behind seawater, ensuring effective and reliable operation of SWHP. 相似文献
18.
Bülent 《浙江大学学报(A卷英文版)》2010,11(2):106-114
In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption （BSFC）. A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons （HC） and NOx emissions increased by 12% and 13% respectively. 相似文献
19.
柴油机排放控制的重点是氮氧化物(NOx)和颗粒物(PM)两种污染物,控制技术措施主要分为机内净化和机外净化方法。以385T型柴油机为例,重点讨论了小型柴油机通过燃烧、喷油、配气系统和机体结构参数优化设计等机内净化技术,可满足国二或国三以上排放标准。随着国四排放法规的逐步实施,必须结合排气后处理技术,可采取的技术路线有"优化燃烧+选择性催化还原(SCR)"和"EGR+柴油颗粒过滤器(DPF)"控制方法。 相似文献
20.
由于自主研发的快速压缩机进气时间长,缸内混合气与活塞、缸壁、缸盖等进行充分热交换而引起进气温度发生变化,影响燃烧特性分析结果。为此对快速压缩机燃烧缸进行测温,分别测得不同混合气温度和不同混合气压力对燃烧缸温度场的影响。结果表明,充气结束20s后燃烧缸内温度场与进气温度及进气压力关系不大,并采用最小二乘法拟合出燃烧缸内平均温度与缸盖上测量热电偶读数间的函数关系,采用修正后的进气温度使发动机模拟试验数据更加真实可靠,提高了燃烧特性分析的精确度和准确度。 相似文献