Numerical Analysis of Flow Characteristics in a Swirl Chamber Type Diesel Engine Depending on Passage Hole Type

Author(s):  
Gyeung Ho Choi ◽  
Tae Yun Kwon ◽  
Ju Hee Yun ◽  
Yon Jong Chung ◽  
Chang Uk Ha ◽  
...  

In a swirl chamber type diesel engine, a strong swirl is produced inside the swirl chamber during the compression stroke. By spraying the fuel into this chamber and thus forming a good mixture, the engine can obtain excellent combustion even at high speeds. Therefore, swirl chamber type diesel engines are favorable for high-speed operations, and because they can produce high power from a small size, they are used often for small, high-speed diesel engine applications. In order to simultaneously realize a reduction in harmful emissions and improvement in fuel consumption of the swirl chamber type diesel engine, reduction of the mixture formation period and complete combustion must be pursued; an optimum combustion chamber to achieve these tasks must first be designed. In this experiment, the effects of the area and the angle of the passage hole, which are the primary design factors of the swirl chamber type diesel engine, on the engine’s turbulent flow will be investigated. Using the commercial numerical analysis program the passage hole area and angle will be varied to analyze the intake and compression stages.

2021 ◽  
Vol 11 (2) ◽  
pp. 25-36
Author(s):  
Mattana Santasnachok ◽  
Ekkachai Sutheerasak ◽  
Charoen Chinwanitcharoen ◽  
Wirogana Ruengphrathuengsuka ◽  
Sathaporn Chuepeng

Particulate matters especially particles with less than 2.5 micrometers (PM2.5) are the main cause of severe air pollution problem in Thailand that lead to the mortality risk in cardiovascular disease. Exhaust gas emissions specifically carbon monoxide and black smoke from diesel engines are the essential sources in generating significant amounts of PM2.5. Improving diesel properties by mixing oxygenated additives is one of the alternatives in reducing this pollutant. The main objective of this research is to investigate the performance and emission of a high-speed diesel engine at 3,000 rpm and different loads operated with diesel mixed with 5 to 20% ethanol and 5% ethyl acetate. The results of engine test at 80% load using diesel mixed with 5% of ethanol and ethyl acetate showed a few decreases in fuel properties and engine performance compared with diesel. The release of black smoke was also decreased to 14%. Increasing the mixture of ethanol to more than 5% has led to the decrease in engine performance continuously. The diesel mixed with ethanol at 20% and ethyl acetate at 5% has reduced the carbon monoxide and black smoke to 0.012%vol and 31.53% respectively and accrued the carbon dioxide at 1.25%vol. This is because the diesel mixed with ethanol and ethyl acetate increased the oxygen level to perform complete combustion as compared with diesel. However, the temperature of these exhaust gases was raised to 55oC


1996 ◽  
Vol 118 (3) ◽  
pp. 637-643 ◽  
Author(s):  
Mei Xuesong ◽  
Xie Youbai

In this paper, by accounting for the effect of dynamic behavior in valve train mechanisms on the surface contact load of a cam/tappet pair, a full numerical solution of nonsteady EHL for a high-speed diesel engine cam/tappet pair is obtained by a fast solution scheme. The shape of the lubricant film and the characteristics of pressure distribution on cam/tappet pair surfaces are further studied. The lubrication process of a cam/tappet pair at the opening and closing sides and in the most dangerous zone in normal working conditions is also analyzed. This analysis provides the theoretical basis which best approximates practical working conditions for designing cam profiles and establishing reasonable running-in condition.


2021 ◽  
Vol 13 (11) ◽  
pp. 6482
Author(s):  
Sergejus Lebedevas ◽  
Laurencas Raslavičius

A study conducted on the high-speed diesel engine (bore/stroke: 79.5/95.5 mm; 66 kW) running with microalgae oil (MAO100) and diesel fuel (D100) showed that, based on Wibe parameters (m and φz), the difference in numerical values of combustion characteristics was ~10% and, in turn, resulted in close energy efficiency indicators (ηi) for both fuels and the possibility to enhance the NOx-smoke opacity trade-off. A comparative analysis by mathematical modeling of energy and traction characteristics for the universal multi-purpose diesel engine CAT 3512B HB-SC (1200 kW, 1800 min−1) confirmed the earlier assumption: at the regimes of external speed characteristics, the difference in Pme and ηi for MAO100 and D100 did not exceeded 0.7–2.0% and 2–4%, respectively. With the refinement and development of the interim concept, the model led to the prognostic evaluation of the suitability of MAO100 as fuel for the FPT Industrial Cursor 13 engine (353 kW, 6-cylinders, common-rail) family. For the selected value of the indicated efficiency ηi = 0.48–0.49, two different combinations of φz and m parameters (φz = 60–70 degCA, m = 0.5 and φz = 60 degCA, m = 1) may be practically realized to achieve the desirable level of maximum combustion pressure Pmax = 130–150 bar (at α~2.0). When switching from diesel to MAO100, it is expected that the ηi will drop by 2–3%, however, an existing reserve in Pmax that comprises 5–7% will open up room for further optimization of energy efficiency and emission indicators.


Author(s):  

The necessity of adapting diesel engines to work on vegetable oils is justified. The possibility of using rapeseed oil and its mixtures with petroleum diesel fuel as motor fuels is considered. Experimental studies of fuel injection of small high-speed diesel engine type MD-6 (1 Ch 8,0/7,5)when using diesel oil and rapeseed oil and computational studies of auto-tractor diesel engine type D-245.12 (1 ChN 11/12,5), working on blends of petroleum diesel fuel and rapeseed oil. When switching autotractor diesel engine from diesel fuel to rapeseed oil in the full-fuel mode, the mass cycle fuel supply increased by 12 %, and in the small-size high-speed diesel engine – by about 27 %. From the point of view of the flow of the working process of these diesel engines, changes in other parameters of the fuel injection process are less significant. Keywords diesel engine; petroleum diesel fuel; vegetable oil; rapeseed oil; high pressure fuel pump; fuel injector; sprayer


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