Numerical model of spray combustion in a single cylinder diesel engine

Author(s):  
Luigi Acampora ◽  
Luigi Sequino ◽  
Giancarlo Nigro ◽  
Gaetano Continillo ◽  
Bianca Maria Vaglieco
Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2362
Author(s):  
Hyungmin Lee

This study was performed to analyze the spray, combustion, and air pollutant characteristic of JP-5 fuel for naval aircraft in a spray visualization system and a single-cylinder CRDI diesel engine that can be visualized. The analysis results of JP-5 fuel were compared with DF. The spray tip penetration of JP-5 showed diminished results as the spray developed. JP-5 had the highest ROHR and ROPR regardless of the fuel injection timings. The physicochemical characteristics of JP-5, such as its excellent vaporization and low cetane number, were analyzed to prolong the ignition delay. Overall, the longer combustion period and the lower heat loss of the DF raised the engine torque and the IMEP. JP-5 showed higher O2 and lower CO2 levels than the DF fuel. The CO emission level increased as the injection timing was advanced in two test fuels, and the CO emitted from the DF fuel, which has a longer combustion period than JP-5, turned out to be lower. NOx also reduced as the fuel injection timing was retarded, but it was discharged at a higher level in JP-5 due to the large heat release. The images from the combustion process visualization showed that the flame luminosity of DF is stronger, its ignition delay is shorter, and its combustion period is longer than that of JP-5.


Author(s):  
M. A. Adzmi ◽  
A. Abdullah ◽  
Z. Abdullah ◽  
A. G. Mrwan

Evaluation of combustion characteristic, engine performances and exhaust emissions of nanoparticles blended in palm oil methyl ester (POME) was conducted in this experiment using a single-cylinder diesel engine. Nanoparticles used was aluminium oxide (Al2O3) and silicon dioxide (SiO2) with a portion of 50 ppm and 100 ppm. SiO2 and Al2O3 were blended in POME and labelled as PS50, PS100 and PA50, PA100, respectively. The data results for PS and PA fuel were compared to POME test fuel. Single cylinder diesel engine YANMAR TF120M attached with DEWESoft data acquisition module (DAQ) model SIRIUSi-HS was used in this experiment. Various engine loads of zero, 7 N.m, 14 Nm, 21 N.m and 28 N.m at a constant engine speed of 1800 rpm were applied during engine testing. Results for each fuel were obtained by calculating the average three times repetition of engine testing. Findings show that the highest maximum pressure of nanoparticles fuel increase by 16.3% compared to POME test fuel. Other than that, the engine peak torque and engine power show a significant increase by 43% and 44%, respectively, recorded during the PS50 fuel test. Meanwhile, emissions of nanoparticles fuel show a large decrease by 10% of oxide of nitrogen (NOx), 6.3% reduction of carbon dioxide (CO2) and a slight decrease of 0.02% on carbon monoxide (CO). Addition of nanoparticles in biodiesel show positive improvements when used in diesel engines and further details were discussed.  


2021 ◽  
Vol 11 (15) ◽  
pp. 6749
Author(s):  
Zhifeng Xie ◽  
Ao Wang ◽  
Zhuoran Liu

The cooling system is an important subsystem of an internal combustion engine, which plays a vital role in the engine’s dynamical characteristic, the fuel economy, and emission output performance at each speed and load. This paper proposes an economical and precise model for an electric cooling system, including the modeling of engine heat rejection, water jacket temperature, and other parts of the cooling system. This model ensures that the engine operates precisely at the designated temperature and the total power consumption of the cooling system takes the minimum value at some power proportion of fan and pump. Speed maps for the cooling fan and pump at different speeds and loads of engine are predicted, which can be stored in the electronic control unit (ECU). This model was validated on a single-cylinder diesel engine, called the DK32. Furthermore, it was used to tune the temperature of the water jacket precisely. The results show that in the common use case, the electric cooling system can save the power of 255 W in contrast with the mechanical cooling system, which is about 1.9% of the engine’s power output. In addition, the validation results of the DK32 engine meet the non-road mobile machinery China-IV emission standards.


2021 ◽  
Vol 1068 (1) ◽  
pp. 012016
Author(s):  
Hazim Sharudin ◽  
N.A. Rahim ◽  
N.I. Ismail ◽  
Sharzali Che Mat ◽  
Nik Rosli Abdullah ◽  
...  

Author(s):  
Mustafa Babagiray ◽  
Hamit Solmaz ◽  
Duygu İpci ◽  
Fatih Aksoy

In this study, a dynamic model of a single-cylinder four-stroke diesel engine has been created, and the crankshaft speed fluctuations have been simulated and validated. The dynamic model of the engine consists of the motion equations of the piston, conrod, and crankshaft. Conrod motion was modeled by two translational and one angular motion equations, by considering the kinetic energy resulted from the mass moment of inertia and conrod mass. Motion equations involve in-cylinder gas pressure forces, hydrodynamic and dry friction, mass inertia moments of moving parts, starter moment, and external load moment. The In-cylinder pressure profile used in the model was obtained experimentally to increase the accuracy of the model. Pressure profiles were expressed mathematically using the Fourier series. The motion equations were solved by using the Taylor series method. The solution of the mathematical model was performed by coding in the MATLAB interface. Cyclic speed fluctuations obtained from the model were compared with experimental results and found compitable. A validated model was used to analyze the effects of in-cylinder pressure, mass moment of inertia of crankshaft and connecting rod, friction, and piston mass. In experiments for 1500, 1800, 2400, and 2700 rpm engine speeds, crankshaft speed fluctuations were observed as 12.84%, 8.04%, 5.02%, and 4.44%, respectively. In simulations performed for the same speeds, crankshaft speed fluctuations were calculated as 10.45%, 7.56%, 4.49%, and 3.65%. Besides, it was observed that the speed fluctuations decreased as the average crankshaft speed value increased. In the simulation for 157.07, 188.49, 219.91, 251.32, and 282.74 rad/s crankshaft speeds, crankshaft speed fluctuations occurred at rates of 10.45%, 7.56%, 5.84%, 4.49%, and 3.65%, respectively. The effective engine power was achieved as 5.25 kW at an average crankshaft angular speed of 219.91 rad/s. The power of friction loss in the engine was determined as 0.68 kW.


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