A Phenomenological Model for Accurate and Time Efficient Prediction of Heat Release and Exhaust Emissions in Direct-Injection Diesel Engines

Author(s):  
Gunnar Stiesch ◽  
Günter P. Merker
Infotekmesin ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 18-22
Author(s):  
Syarifudin Syarifudin ◽  
Syaiful Syaiful

Diesel engines are widely used as driving forces in vehicles and industry due to fuel efficiency and high output power. The wide use of diesel engines triggers an increase in fuel consumption and exhaust emissions that are harmful to health. Jatropha is a renewable fuel as a solution to increase fuel consumption. However, the high viscosity and low calorific value result in reduced performance and increased exhaust emissions. Butanol has a high oxygen content and cetane number and low viscosity compared to diesel and jatropha. Addition of butanol is possible to reduce the decrease in performance and exhaust emissions of diesel engines. this study evaluates the effect of butanol on reducing Isuzu 4JB1 diesel engine direct injection emissions. Percentage of blend used 70/30/0, 65/30/5, 60/30/10, and 55/40/15 based on volume. Tests are carried out at 2500 constant turns with a loading of 25% to 100% using the EGR system. The experimental results showed the presence of butanol caused a decrease in soot emissions produced by diesel engines


Author(s):  
F J Wallace ◽  
J G Hawley

This paper is a further development of work previously reported on a wholly analytical approach to heat release modelling and is applicable to high-speed direct injection (HSDI) diesel engines operating with high-pressure common rail fuel injection systems under conditions of predominantly mixing-controlled combustion. The key variable in this treatment is the fuel preparation or combustion rate factor WH which, in conjunction with the primary injection variables, i.e. rail pressure, injection velocity and duration, defines the shape and amplitude of the heat release curve. It was shown in a previous paper that by expressing the fuel preparation rate factor WH as a function of time rather than crank angle, i.e. WHt instead of WHθ, the former can be presented as a nearly linear function of the square of injection velocity, i.e. WHt is directly proportional to the kinetic energy of the injected fuel spray, the latter evidently being the primary influence on the rate of the fuel-air mixing process. The analytical treatment developed in the authors' previous paper then allows heat release rates in the engine, dQ/dθ, to be calculated over a wide range of engine speeds and loads, with the aid of the existing engine simulation code ODES (Otto diesel engine simulation) to predict the associated engine performance and emissions, without resorting to further engine testing.


Author(s):  
N. A. Henein ◽  
I. P. Singh ◽  
L. Zhong ◽  
Y. Poonawala ◽  
J. Singh ◽  
...  

This paper introduces a phenomenological model for the fuel distribution, combustion, and emissions formation in the small bore, high speed direct injection diesel engine. A differentiation is made between the conditions in large bore and small bore diesel engines, particularly regarding the fuel impingement on the walls and the swirl and squish gas flow components. The model considers the fuel injected prior to the development of the flame, fuel injected in the flame, fuel deposited on the walls and the last part of the fuel delivered at the end of the injection process. The model is based on experimental results obtained in a single-cylinder, 4-valve, direct-injection, four-stroke-cycle, water-cooled, diesel engine equipped with a common rail fuel injection system. The engine is supercharged with heated shop air, and the exhaust back pressure is adjusted to simulate actual turbo-charged diesel engine conditions. The experiments covered a wide range of injection pressures, EGR rates, injection timings and swirl ratios. Correlations and 2-D maps are developed to show the effect of combinations of the above parameters on engine out emissions. Emphasis is made on the nitric oxide and soot measured in Bosch Smoke Units (BSU).


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