scholarly journals Theoretical and Experimental Studies on Diesel Engine Combustion

1982 ◽  
Vol 17 (11) ◽  
pp. 925-931
Author(s):  
Masayoshi Kawakami
2012 ◽  
Vol 36 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Chandrashekharapua Ramachandraiah Rajashekhar ◽  
Tumkur Krishnamurthy Chandrashekar ◽  
Chebbiyyan Umashankar ◽  
Rajagopal Harish Kumar

Combustion of biodiesels has inherent problems due to their high viscosity and low volatility. This paper relates the modification of engine combustion chamber design, for inducing turbulence to improve the combustibility of combustible mixture. A survey of literature shows that experimental studies have not been done on a tri-chambered piston for evaluating influence on the performance and emission characteristics using diesel blends as well. The objective of this work is to study the effect of combustion chamber geometry and injection pressure on performance and emissions of a biodiesel (Jatropha) fuelled multi-chambered piston diesel engine. The performance and emission characteristics were studied and it has been noticed that for the engine under consideration 200 bar injection pressure gives optimum performance.


Author(s):  
J. J. Macfarlane ◽  
F. H. Holderness

Experimental studies are described in which continuous flow model flames of uniform composition are used to examine the effects of the individual variation of the main combustion parameters on flame composition and radiation. A detailed description is given of the chemical and physical behaviour of rich, high-pressure hydrocarbon–air flames and comparison is made with the results of previous work at N.G.T.E. on small premixed flames of C5 and C6 hydrocarbons and on the constant volume combustion of rich methane–oxygen mixtures. It is shown that there is considerable similarity between the combustion processes in the modern gas turbine and the diesel engine and that conclusions which are important in diesel engine combustion can be drawn from continuous flow experiments of this kind.


2017 ◽  
Vol 20 (2) ◽  
pp. 203-215 ◽  
Author(s):  
Zongyu Yue ◽  
Rolf D Reitz

High-pressure fuel injection impacts mixture preparation, ignition and combustion in engines and other applications. Experimental studies have revealed the mixing-controlled and local phase equilibrium characteristics of liquid vaporization in high injection pressure diesel engine sprays. However, most computational fluid dynamics models for engine simulations spend much effort in solving for non-equilibrium spray processes. In this study, an equilibrium phase spray model is explored. The model is developed based on jet theory and a phase equilibrium assumption, without modeling drop breakup, collision and finite-rate interfacial vaporization processes. The proposed equilibrium phase spray model is validated extensively against experimental data in simulations of the engine combustion network Spray A and in an optical diesel engine. Predictions of liquid/vapor penetration, fuel mass fraction distribution, heat release rate and emission formation are all in good agreement with experimental data. In addition, good computational efficiency and grid-independency are also seen with the present equilibrium phase model. The examined operating conditions cover wide ranges that are relevant to internal combustion engines, which include ambient temperatures from 700 to 1400 K, ambient densities from 7.6 to 22.8 kg/m3 and injection pressures from 1200 to 1500 bar for diesel sprays.


Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.


2020 ◽  
pp. 22-30
Author(s):  
SERGEY N. DEVYANIN ◽  
◽  
VLADIMIR A. MARKOV ◽  
ALEKSANDR G. LEVSHIN ◽  
TAMARA P. KOBOZEVA ◽  
...  

The paper presents the results of long-term research on the oil productivity and chemical composition of soybean oil of the Northern ecotype varieties in the Central Non-Black Earth Region. The authors consider its possible use for biodiesel production. Experiments on growing soybeans were carried out on the experimental fi eld of Russian State Agrarian University –Moscow Timiryazev Agricultural Academy (2008-2019) on recognized ultra-early ripening varieties of the Northern ecotype Mageva, Svetlaya, Okskaya (ripeness group 000). Tests were set and the research results were analyzed using standard approved methods. It has been shown that in conditions of high latitudes (57°N), limited thermal resources of the Non-Chernozem zone of Russia (the sum of active temperatures of the growing season not exceeding 2000°С), the yield and productivity of soybeans depend on the variety and moisture supply. Over the years, the average yield of soybeans amounted to 1.94 … 2.62 t/ha, oil productivity – 388 … 544 kg/ha, oil content – 19…20%, the content of oleic and linoleic fatty acids in oil – 60%, and their output from seeds harvested – 300 kg/ha. It has been established that as soybean oil and diesel fuel have similar properties,they can be mixed by conventional methods in any proportions and form stable blends that can be stored for a long time. Experimental studies on the use of soybean oil for biodiesel production were carried out on a D-245 diesel engine (4 ChN11/12.5). The concentrations of toxic components (CO, CHx, and NOx) in the diesel exhaust gases were determined using the SAE-7532 gas analyzer. The smoke content of the exhaust gases was measured with an MK-3 Hartridge opacimeter. It has been experimentally established that the transfer of a diesel engine from diesel fuel to a blend of 80% diesel fuel and 20% lubrication oil leads to a change in the integral emissions per test cycle: nitrogen oxides in 0.81 times, carbon monoxide in 0.89 times and unburned hydrocarbons in 0.91 times, i.e. when biodiesel as used as a motor fuel in a serial diesel engine, emissions of all gaseous toxic components are reduced. The study has confi rmed the expediency of using soybeans of the Northern ecotype for biofuel production.


1977 ◽  
Vol 16 (1) ◽  
pp. 321-336 ◽  
Author(s):  
G. Greeves ◽  
I.M. Khan ◽  
G. Onion

2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.


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