基于火焰图像的燃油燃烧室温度场测量

介绍三种比色测温方法的测量原理 ,对它们的优缺点进行了说明 ,并通过实验对其中的单色测量法及 CCD分色测量法进行了验证和评价 .

Solution of idle LBO problem for high FAR aero combustor

The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor design is required to resolve the idle LBO issue.The authors detailed a practical and efficient solu⁃tion,which not only solved the idle LBO issue but also defined the aero-thermal design for high-FAR combustor.The design will usher in a new era of aero combustor.

汽车发动机的日常维护与保养措施初探

随着科学技术的全面发展,汽车作为人们出行的主要交通工具之一,得到了不断的普及,汽车发动机的维护和保养工作得到了人们的重视,因此,本文对汽车发动机的维修与保养工作展开了全面的分析。首先简单分析了汽车发动机日常故障问题和造成故障的原因,进而有针对性的从滤芯、发动机系统、曲轴箱、燃油室、水箱等方面入手,具体阐述维护保养的具体措施,以此为汽车发动机维护人员提供参考。

喷油嘴常见故障及排除

喷油嘴是柴油机燃油供给系统的重要部件，由喷油头、针阀、罩帽、壳体回油道、进油道、弹簧、调整螺钉等组成，安装在气缸盖上。主要功能是把柴油碎破成雾状，散布到燃油室中去。喷油嘴一旦出了故障，就会影响柴油机正常工作。现将喷油嘴的常见故障及维修方法简述如下。

The Impact of Optimizing Trim on Reducing Fuel Consumption

The shipping industry is one of the biggest industries throughout the ages. Maritime transport plays a vital role in world economy; whereas competition between maritime companies is fierce [1], at the same time agreements of co-operation have taken different forms including alliances and mergers between companies to increase their market share. But competitions still stand despite all alliances even in same market. This intense competition drives companies to attain high level of competitiveness, by monitoring ship＇s operating performance and operating cost, emphasis on improving performance and reduce cost. On other hand new environmental regulations come to light, expansion of ECA （emission control areas）, which lead to significant higher fuel cost when using low sulfur fuel. Since the fuel cost is the largest portion of the operating cost of the vessel, a saving in fuel usage can result in considerable saving in operational costs. Furthermore, fuel saving has environmental benefits in the reduction of greenhouse gas emissions. The aim of this paper is to investigate the role of trim optimization which considers one of the easiest and cheapest methods for ship performance optimization and fuel consumption reduction trim optimization.

Effect of Gasoline Property on Formation of Intake Valve and Combustion Chamber Deposits

The cleanliness of gasoline is related to its components and properties.All commercial gasoline builds up deposits on the engine's injector,intake valve and combustion chamber,which can significantly lower the engine performance and influence exhaust gas emissions.In this study,the intake valve deposits (IVD) and combustion chamber deposits (CCD) produced from combustion of fuel containing 21 v%—42 v% of aromatics and 8 v%—31 v% of olefins have been studied using Ford engine tests,and the characteristics of deposits were studied by IR spectroscopy,TGA and elemental analysis instrument.The test results have shown that deposit formation depends on the fuel composition,especially the aromatic content in the fuel.It is also observed that there are differences in the values of IVD and CCD measured by IR spectrometry and elemental analyses.

The Impact of Ethanol as a Fuel in the Gas Emissions

This work deals with the examination of farm tractor with diesel engine from the viewpoint of power and gas emissions, using as fuel diesel-ethanol mixtures. A series of laboratory instruments was used for the realization of the experiments. The tractor engine is functioning under full load conditions. The experimental results have shown small reduction of power engine with simultaneously remarkable reduction of CO and HC emissions.

Thermal and elemental analysis of the combustion chamber deposits in a large-scale two-stroke marine diesel engine

It is of significance to understand the chemical content of carbon deposits in the large-scale two-stroke(LSTS) marine diesel engine because of adverse effect on the engine performance, oil consumption and emissions. In this work, two different combustion chamber deposits in an LSTS marine diesel engine were studied using thermogravimetry analysis(TGA), elemental analysis(EA) and synchrotron X-ray fluorescence(SXRF). One was on the piston top and the other on the piston land, termed PTCD and PLCD, respectively. For the PTCD sample, the 97% residue in the TGA and 1.4% carbon content in the EA indicated the main compositions of PTCD were metal salts or oxides and ashes, significantly different from the previous findings of the highest carbon content in deposits from the small four stroke engines. The different chemical content between PTCD and PLCD implied higher thermal load in the LSTS marine diesel engine led to a nearly complete thermal decomposition of PTCD. The higher calcium content in PTCD and PLCD indicated the additives of cylinder oil should be the main source of metal content of PTCD and PLCD. Calcium distribution in the SXRF results was indicative of the potential layered structure in PTCD and PLCD. In addition, the appearance of iron on the surface against the piston in PTCD and PLCD indicated iron oxides formation between carbon deposit and piston materials.

Numerical Investigation of the Flow inside the Combustion Chamber of a Plant Oil Stove

Recently a low cost cooking device for developing and emerging countries was developed at KIT in cooperation with the company Bosch und Siemens Hausger^ite GmbH. After constructing an innovative basic design further development was required. Numerical investigations were conducted in order to investigate the flow inside the combustion chamber of the stove under variation of different geometrical parameters. Beyond the performance improvement a further reason of the investigations was to rate the effects of manufacturing tolerance problems. In this paper the numerical investigation of a plant oil stove by means of RANS simulation will be presented. In or- der to reduce the computational costs different model reduction steps were necessary. The simulation results of the basic configuration compare very well with experimental measurements and problematic behaviors of the ac- tual stove design could be explained by the investigation.

Supersonic Cavity Based Combustion with Kerosene/Hydrogen Fuel

A comparative study with kerosene and hydrogen fuel in a model scramjet combustor has been carried out nu- merically. The effect of fuel-air equivalence ratio on the flow field properties in a cavity based mixing mechanism at a freestream Math number of 2.08 has been probed. The investigation has been carried out in a two dimension- al numerical model where a cavity of length to depth ratio of 2 is mounted on one of the walls of the flow channel The flow field shock structure is observed to change with the change in fuel-air equivalence ratio. Total pressure loss is observed to depend both on fuel air equivalence ratio and the fuel type. The spread of fuel in the test sec- tion shows marked variation with the equivalence ratio. Performance of injector location on the fuel-air mixing is also probed during the course of the investigation.