scholarly journals Computational fluid dynamics modelling of non-premixed combustion in direct injection diesel engines

2000 ◽  
Vol 1 (3) ◽  
pp. 249-267 ◽  
Author(s):  
H Barths ◽  
C Hasse ◽  
N Peters

An overview over flamelet modelling for turbulent non-premixed combustion is given. A short review of previous contributions to simulations of direct injection (DI) diesel engine combustion using the representative interactive flamelet concept is presented. A surrogate fuel consisting of 70 per cent (liquid volume) n-decane and 30 per cent α-methyl-naphthalene is experimentally compared to real diesel fuel. The resemblance of their physical and chemical properties is shown to result in very similar combustion and pollutant formation for both fuels. In order to account for variations of the scalar dissipation rate within the computational domain, a method using multiple flamelets, called the Eulerian particle flamelet model, is used. A strategy is described for subdividing the computational domain and assigning the resulting subdomains to different flamelet histories represented by Eulerian marker particles. Experiments conducted with an Audi DI diesel engine and diesel fuel are compared to simulations using the surrogate fuel. The use of multiple flamelets, each having a different history, significantly improves the description of the ignition phase, leading to a better prediction of pressure, heat release and exhaust emissions of soot and NOx. The effect of the number of flamelet particles on the predictions is discussed.

2021 ◽  
Author(s):  
Thanigaivelan V ◽  
Lavanya R

Abstract Emission from the DI diesel engine is series setback for environment viewpoint. Intended for that investigates for alternative biofuel is persuaded. The important hitches with the utilization of biofuels and their blends in DI diesel engines are higher emanations and inferior brake-thermal efficiency as associated to sole diesel fuel. In this effort, Cashew nut shell liquid (CNSL) biodiesel, hydrogen and ethanol (BHE) mixtures remained verified in a direct-injection diesel engine with single cylinder to examine the performance and discharge features of the engine. The ethanol remained supplemented 5%, 10% and 15% correspondingly through enhanced CNSL as well as hydrogen functioned twin fuel engine. The experiments done in a direct injection diesel engine with single-cylinder at steadystate conditions above the persistent RPM (1500RPM). Throughout the experiment, emissions of pollutants such as fuel consumption rate (SFC), hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx) and pressure of the fuel were also measured. cylinders. The experimental results show that, compared to diesel fuel, the braking heat of the biodiesel mixture is reduced by 26.79-24% and the BSFC diminutions with growing addition of ethanol from the CNSL hydrogen mixture. The BTE upsurges thru a rise in ethanol proportion with CNSL hydrogen mixtures. Finally, the optimum combination of ethanol with CNSL hydrogen blends led to the reduced levels of HC and CO emissions with trivial upsurge in exhaust gas temperature and NOx emissions. This paper reconnoiters the routine of artificial neural networks (ANN) to envisage recital, ignition and discharges effect.


2007 ◽  
Vol 21 (5) ◽  
pp. 2642-2654 ◽  
Author(s):  
Theodoros C. Zannis ◽  
Dimitrios T. Hountalas ◽  
Roussos G. Papagiannakis

2021 ◽  
Vol 39 (5A) ◽  
pp. 790-803
Author(s):  
Hussein Jumaa ◽  
Mahmoud A. Mashkour

The effect of humidification of the air on the performance of a compression ignition engine operating on diesel, biodiesel with nano additives was investigated. The experiment was carried out on a single-cylinder, four-stroke, naturally aspirated water-cooled, direct injection Ricardo (E6/US) diesel engine at a constant speed of 1800 rpm, and varying loads. A mixture of Biodiesel (waste cooking oil) and diesel fuel by four ratios (B5, B10, B15, and B20) was used in the experiment. Besides, five concentrations of Iron oxide nanoparticles (Fe2O3, with particle size 20 nm) as fuel-additives were prepared (10 ppm, 30 ppm, 50 ppm, 70 ppm, and 100 ppm), and added to the test fuels (Bio-Diesel).  Taguchi Method by DOE was used for the optimization in this investigation. The results of Taguchi Method experiments identified the biodiesel (B20), nano additive (100 ppm), relative humidity (65%). The experimental results manifested that BTE improved by 17.62% and BSFC decreased by 12.72%, while NOx and PM reduced by 8.45%, 24.17%, respectively.


Transport ◽  
2014 ◽  
Vol 29 (4) ◽  
pp. 440-448 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Slawomir Wierzbicki ◽  
Kamil Duda

This paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 min–1 speed. At rated mode, the minimum bsfc increased, when operating on biofuel blends compared to mineral diesel. The maximum brake thermal efficiency sustained at the levels from 0.3% to 6.5% lower in comparison with mineral diesel operating at full (100%) load. When the engine was running at maximum torque mode using diesel – RME fuel blends B10, B20, B40 and B60 the total emissions of nitrogen oxides decreased. At full and moderate load, the emission of carbon monoxide significantly raised as the amount of RME in fuel increased.


Author(s):  
V. Anandram ◽  
S. Ramakrishnan ◽  
J. Karthick ◽  
S. Saravanan ◽  
G. LakshmiNarayanaRao

In the present work, the combustion, performance and emission characteristics of sunflower oil, sunflower methyl ester and its blends were studied and compared with diesel by employing them as fuel in a single cylinder, direct injection, 4.4 KW, air cooled diesel engine. Emission measurements were carried out using five-gas exhaust gas analyzer and smoke meter. The performance characteristics of Sunflower oil, Sunflower methyl ester and its blends were comparable with those of diesel. The components of exhaust such as HC, CO, NOx and soot concentration of the fuels were measured and presented as a function of load and it was observed that the blends had similar performance and emission characteristics as those of diesel. NOx emissions of sunflower oil methyl ester were slightly higher than that of diesel but that of sunflower oil was slightly lower than that of diesel. With respect to the combustion characteristics it was found that the biofuels have lower ignition delay than diesel. The heat release rate was very high for diesel than for the biofuel.


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