Optimal Design of a Two-Stroke Diesel Engine for Aeronautical Applications Concerning Both Thermofluidynamic and Acoustic Issues

2008 ◽  
Author(s):  
Daniela Siano ◽  
Michela Costa ◽  
Fabio Bozza
Keyword(s):  
Diesel Engine ◽  
Acoustic Analysis ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Engine Performance ◽  
Combustion Noise ◽  
Process Efficiency ◽  
Injection System ◽  
Common Rail Injection System ◽  
First Choice

Some aspects concerning the development of a prototype of a diesel engine suitable for aeronautical applications are discussed. The engine aimed at achieving a weight to power ratio equal to one kg/kW (220 kg for 220 kW) is conceived in a two stroke Uniflow configuration and constituted by six cylinders distributed on two parallel banks. Basing on a first choice of some geometrical and operational data, a preliminary fluid-dynamic and acoustic analysis is carried out at the sea level. This includes the engine-turbocharger matching, the estimation of the scavenging process efficiency, and the simulation of the spray and combustion process, arising from a Common Rail injection system. Both 1D and 3D CFD models are employed. In-cylinder pressure cycles are utilized to numerically predict the combustion noise. The acoustic study is based on the integration of FEM/BEM codes. In order to improve the engine performance and vibro-acoustic behaviour, the 1D model, tuned with information derived from the 3D code, is linked to an external optimiziation code (ModeFRONTIER™). A constrained multi-objective optimization is performed to contemporary minimize the fuel consumption and the maximum in-cylinder temperature and pressure gradient. In this way a better selection of a number of engine parameters is carried out (exhaust valve opening, closing and lift, intake ports heights, start of injection, etc). The best found solution is finally compared to the initial one and some substantial design improvements are discussed.

scholarly journals Theoretical study to determine the proper injection system for upgrading fuel system of diesel engine om357 to common rail system

2018 ◽  
Vol 7 (4) ◽  
pp. 2594
Author(s):  
Razieh Pourdarbani ◽  
Ramin Aminfar
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Common Rail ◽  
Injection System ◽  
Injection Timing ◽  
Common Rail System ◽  
Common Rail Injection System ◽  
Multi Stage

In this research, we tried to investigate all the fuel injection systems of diesel engines in order to select the most suitable fuel injection system for the OM357 diesel engine to achieve the highest efficiency, maximize output torque and reduce emissions and even reduce fuel consumption. The prevailing strategy for this study was to investigate the effect of injection pressure changes, injection timing and multi-stage injection. By comparing the engines equipped with common rail injection system, the proposed injector for engine OM357 is solenoid, due to the cost of this type of injector, MAP and controller (ECU). It is clear that this will not be possible only with the optimization of the injection system, and so other systems that influence engine performance such as the engine's respiratory system and combustion chamber shape, etc. should also be optimized. 

scholarly journals RME CO-COMBUSTION WITH HYDROGEN IN COMPRESSION IGNITION ENGINE: PERFORMANCE, EFFICIENCY AND EMISSIONS / SLĖGINIO UŽDEGIMO VARIKLIO ENERGINIŲ, EFEKTYVUMO IR DEGINIŲ EMISIJOS RODIKLIŲ TYRIMAS NAUDOJANT RAPSŲ METILESTERĮ IR VANDENILĮ

2018 ◽  
Vol 10 (0) ◽  
pp. 1-9
Author(s):  
Romualdas Juknelevičius
Keyword(s):  
Combustion Process ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Common Rail ◽  
Injection System ◽  
Intake Manifold ◽  
Compression Ignition Engine ◽  
Common Rail Injection System ◽  
Wide Range ◽  
The Rich

The article presents the test results of the single cylinder CI engine with common rail injection system operating on biofuel – Rapeseed Methyl Ester with addition supply of hydrogen. The purpose of this investigation was to examine the influence of the hydrogen addition to the biofuel on combustion phases, engine performance, efficiency, and exhaust emissions. HES was changed within the range from 0 to 44%. Hydrogen was injected into the intake manifold, where it created homogeneous mixture with air. Tests were performed at both fixed and optimal injection timings at low, medium and nominal engine load. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that lean hydrogen – RME mixture does not support the flame propagation and efficient combustion. While at the rich fuel mixture and with increasing hydrogen fraction, the combustion intensity concentrate at the beginning of the combustion process and shortened the ignition delay phase. AVL BOOST simulation performed within the wide range of HES (16–80%) revealed that combustion intensity moves to the beginning of combustion with increase of HES. Decrease of CO, CO2 and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the NO concentration in the engine exhaust gases was observed. Santrauka Straipsnyje pateikti tyrimo rezultatai, gauti atlikus bandymą vieno cilindro slėginio uždegimo variklyje su biodegalais – rapsų metilesterį (RME) ir vandenilį. Biodegalai įpurškiami akumuliatorine įpurškimo sistema „Common rail“. Šio tyrimo tikslas – ištirti, kaip vandenilis veikia biodegalų degimą, variklio veikimą, jo efektyvumą ir deginių susidarymą. Vandenilio energinė dalis degimo mišinyje buvo keičiama nuo 0 iki 44 %. Vandenilis buvo tiekiamas įsiurbimo fazės metu įsiurbimo kanalu į degimo kamerą, kurioje jis, susimaišęs su oru, sudaro homogeninį mišinį. Bandymai buvo atliekami nekeičiant įpurškimo kampo, nustačius optimalų įpurškimo kampą esant žemai, vidutinei ir nominaliai variklio apkrovai. Išnagrinėjus variklio bandymų rezultatus ir sumodeliavu AVL BOOST programa, buvo pastebėta, kad, esant liesam vandenilio ir RME mišiniui, liepsnos plitimas yra lėtas, mišinys dega neveiksmingai. Tačiau riebus degalų mišinys ir padidinta vandenilio energijos dalis užtikrina degimo intensyvumą degimo proceso pradžioje ir sutrumpina uždegimo gaišties trukmę. AVL BOOST modeliavimas, atliktas plačiu vandenilio energijos dalies diapazonu (16–80 %), patvirtino teiginį, kad degimas tampa intensyvesnis degimo pradžioje dėl padidinto vandenilio kiekio. Didinant vandenilio kiekį, buvo pastebėta, kad išmetamosiose dujose sumažėjo CO, CO2 ir kietųjų dalelių, tačiau padidėjo NO koncentracija.

Accelerometer Signal to Characterize the Combustion Development in Multiple Injection Diesel Engine

2012 ◽  
Author(s):  
G. Chiatti ◽  
O. Chiavola ◽  
E. Recco
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Vibration Signal ◽  
Injection System ◽  
Cylinder Pressure ◽  
Multiple Injection ◽  
Real Time Control ◽  
Common Rail Injection System ◽  
Crank Angle

This work constitutes one of the last steps of a comprehensive research program in which vibration sensors are used with the purpose of developing and setting up a methodology that is able to perform a real time control of the combustion process by means of non-intrusive measurements. Previous obtained and published results have demonstrated that a direct relationship exists between in-cylinder pressure and engine block vibration signals. The analysis of the processed data have highlighted that the block vibration signal may be used to locate, in the crank–angle domain, the combustion phases (the start of the combustion, the crank angle value corresponding to the beginning of main combustion and to the in-cylinder pressure maximum value) and to quantify the in-cylinder pressure development by evaluating the pressure peak value and the pressure rise rate caused by the combustion process. The aim of this work is to extend and validate the developed methodology when a multiple-injection strategy is imposed on the engine. The paper presents the results obtained during the experimentation of a two cylinder diesel engine equipped with a common rail injection system, that was performed in the Laboratory of the Mechanical and Industrial Department of ‘ROMA TRE’ University. During the tests, a wide variation of the injection parameters settings is imposed on the engine (timing and duration) in its complete operative field.

scholarly journals Effects of Injection Rate Profile on Combustion Process and Emissions in a Diesel Engine

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Fuqiang Bai ◽  
Zuowei Zhang ◽  
Yongchen Du ◽  
Fan Zhang ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Combustion Process ◽  
Injection Rate ◽  
Injection System ◽  
Nox Emissions ◽  
Release Process ◽  
Common Rail Injection System ◽  
Soot Emissions ◽  
Rate Profile

When multi-injection is implemented in diesel engine via high pressure common rail injection system, changed interval between injection pulses can induce variation of injection rate profile for sequential injection pulse, though other control parameters are the same. Variations of injection rate shape which influence the air-fuel mixing and combustion process will be important for designing injection strategy. In this research, CFD numerical simulations using KIVA-3V were conducted for examining the effects of injection rate shape on diesel combustion and emissions. After the model was validated by experimental results, five different shapes (including rectangle, slope, triangle, trapezoid, and wedge) of injection rate profiles were investigated. Modeling results demonstrate that injection rate shape can have obvious influence on heat release process and heat release traces which cause different combustion process and emissions. It is observed that the baseline, rectangle (flat), shape of injection rate can have better balance between NOx and soot emissions than the other investigated shapes. As wedge shape brings about the lowest NOx emissions due to retarded heat release, it produces the highest soot emissions among the five shapes. Trapezoid shape has the lowest soot emissions, while its NOx is not the highest one. The highest NOx emissions were produced by triangle shape due to higher peak injection rate.

Direct Injection Diesel Engine Performance Improvement and Emission Control using Boost Pressure

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
R. Senthil ◽  
R. Silambarasan ◽  
G. Pranesh
Keyword(s):  
Diesel Engine ◽  
Performance Improvement ◽  
Direct Injection ◽  
Combustion Process ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection System ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Engine Exhaust

The present investigation is to analyse the influence of boost pressure and injection pressure on combustion process and emissions for various engine loads and speeds. A single cylinder diesel engine that is equipped with a manual direct injection system is considered for the experimental work. Emissions such as HC, NOx and brake specific fuel consumption were monitored using gas analyzer. A turbocharger and dilution tunnel is designed such a way that a boost pressure will be created from the compressor driven turbine using engine exhaust. The compressed air was mixed with the exhaust gas in the dilution tunnel to oxidize the hydrogen and carbon into water vapour and carbon dioxide.

Optimization of Skewed Injection for High Swirl, Two-Cycle, Diesel Engine

2012 ◽  
Author(s):  
Deep Bandyopadhyay
Keyword(s):  
Diesel Engine ◽  
Negative Impact ◽  
Fluid Dynamic ◽  
Injection Pressure ◽  
Combustion Efficiency ◽  
Injection System ◽  
Common Rail Injection System ◽  
Medium Speed ◽  
Common Rail Injection ◽  
Inherent Advantage

Generally, two-stroke engines have inherent advantage of higher swirl, as compared to four-stroke engines. Higher swirl helps with better mixing and atomization for mechanical and low pressure, electronic, unit injectors. With the introduction of higher injection pressure, the advantage of swirl reduced to a point in which it started to have a negative impact. In this work, the goal was to optimize a high pressure, common rail injection system for heavy-duty, two-cycle, medium speed, diesel engine (710 cubic inches of displacement per cylinder) under high load. A proprietary multi-dimensional computational fluid dynamic (CFD) code was used for the modeling work. Here, we optimized the new, skewed injection system, which takes advantage of swirl and further helps in atomization of spray. The spray in this study is introduced at a radial angle, which is aligned either along or against the swirl direction. The results showed significant improvement in combustion efficiency. Combustion efficiency is estimated as a decrease in fuel consumption and CO values. Emission parameters, such as nitrogen oxide and soot were also studied and showed significant reductions.

scholarly journals EXPERIMENTAL INVESTIGATIONS OF HYDROGEN EFFECTS ON PERFORMANCE AND EMISSIONS OF RENEWABLE DIESEL FUELED RCCI / VANDENILIO ĮTAKA ENERGINIAMS IR EMISIJOS RODIKLIAMS ALTERNATYVIU DYZELINU VEIKIANČIAME RCCI VARIKLYJE – EKSPERIMENTINIS TYRIMAS

2018 ◽  
Vol 10 (0) ◽  
pp. 1-10
Author(s):  
Romualdas Juknelevičius
Keyword(s):  
Combustion Chamber ◽  
Combustion Process ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Injection System ◽  
Experimental Investigations ◽  
Renewable Diesel ◽  
Common Rail Injection System ◽  
Performance And Emissions ◽  
The Rich

The article presents the study of hydrogen effects on performance, combustion and emissions characteristics of renewable diesel fueled single cylinder CI engine with common rail injection system in RCCI mode. The renewable diesel fuels as the HRF are the HVO and it blend with petrol diesel further named PRO Diesel, investigated in this study. The purpose of this investigation was to examine the influence of the LRF – hydrogen addition to the HRF on combustion phases, engine performance, efficiency, and exhaust emissions. HES was changed within the range from 0 to 35%. Hydrogen injected through PFI during intake stroke to the combustion chamber, where it created homogeneous mixture with air. The HRF was directly injected into combustion chamber using electronic controlled unit. Tests were performed at both fixed and optimal injection timings at low, medium and nominal engine load. After analysis of the engine bench results, it was observed that lean hydrogen – HRF mixture does not support the flame propagation and efficient combustion. While at the rich fuel mixture and with increasing hydrogen fraction, the combustion intensity concentrate at the beginning of the combustion process and shortened the ignition delay phase. Decrease of CO, CO2 and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the NO concentration in the engine exhaust gases was observed.

Diesel engine performance mapping using a parametrized mixing time model

2017 ◽  
Vol 19 (2) ◽  
pp. 202-213 ◽  
Author(s):  
Michal Pasternak ◽  
Fabian Mauss ◽  
Christian Klauer ◽  
Andrea Matrisciano
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Mixing Time ◽  
Combustion Process ◽  
Engine Performance ◽  
Injection Timing ◽  
Engine Control ◽  
Reactor Model ◽  
Time Model ◽  
Tabulated Chemistry

A numerical platform is presented for diesel engine performance mapping. The platform employs a zero-dimensional stochastic reactor model for the simulation of engine in-cylinder processes. n-Heptane is used as diesel surrogate for the modeling of fuel oxidation and emission formation. The overall simulation process is carried out in an automated manner using a genetic algorithm. The probability density function formulation of the stochastic reactor model enables an insight into the locality of turbulence–chemistry interactions that characterize the combustion process in diesel engines. The interactions are accounted for by the modeling of representative mixing time. The mixing time is parametrized with known engine operating parameters such as load, speed and fuel injection strategy. The detailed chemistry consideration and mixing time parametrization enable the extrapolation of engine performance parameters beyond the operating points used for model training. The results show that the model responds correctly to the changes of engine control parameters such as fuel injection timing and exhaust gas recirculation rate. It is demonstrated that the method developed can be applied to the prediction of engine load–speed maps for exhaust NOx, indicated mean effective pressure and fuel consumption. The maps can be derived from the limited experimental data available for model calibration. Significant speedup of the simulations process can be achieved using tabulated chemistry. Overall, the method presented can be considered as a bridge between the experimental works and the development of mean value engine models for engine control applications.

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