scholarly journals Modeling the effect of spray/wall impingement on combustion process and emission of DI diesel engine

2009 ◽  
Vol 13 (3) ◽  
pp. 23-33 ◽  
Author(s):  
Samad Jafarmadar ◽  
Shram Khalilarya ◽  
Sina Shafee ◽  
Ramin Barzegar
Keyword(s):  
Diesel Engine ◽  
Film Formation ◽  
Direct Injection ◽  
Combustion Process ◽  
Three Dimensional ◽  
Three Dimensional Modeling ◽  
Wall Film ◽  
Wall Impingement ◽  
Di Diesel Engine ◽  
Fuel Mixing

This work is presented to study the effect of spray impinging on the combustion process and emissions in a direct injection diesel engine at various engine speeds. Computations are carried out using a three-dimensional modeling for sprays, spray-wall interactions, flow field, emission, and combustion process. Results indicate an increase in engine speed leads to increased spray impinging (wall film formation), turbulence intensity and average wall temperature in cylinder. The enhanced air/fuel mixing and intensified evaporation of wall film decreases soot emission by reducing the extent of the fuel rich regions specially in impinging zones. Also at higher engine speeds, combustion is delayed and fuel is consumed in a shorter time period by the enhanced air and fuel mixing. The shorter combustion duration provides less available time for soot and NOx formations. However, only a few attempts have been made to address the effect of impingement of spray with piston walls on the emissions and combustion process. The results of model in addition to approving the corresponding data in the literature are also compared with the experimental data and shown good agreement.

Effects of the Re-Entrant Bowl Geometry on a DI Turbocharged Diesel Engine Performance and Emissions—A CFD Approach

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
S. Pasupathy Venkateswaran ◽  
G. Nagarajan
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Combustion Process ◽  
Engine Performance ◽  
Maximum Diameter ◽  
Diffusion Combustion ◽  
Turbocharged Diesel Engine ◽  
Performance And Emissions ◽  
Di Diesel Engine ◽  
Fuel Mixing

The purpose of this study is to investigate the influence of re-entrant bowl geometry on both engine performance and combustion efficiency in a direct injection (DI), turbocharged diesel engine for heavy-duty applications. The piston bowl design is one of the most important factors that affect the air–fuel mixing and the subsequent combustion and pollutant formation processes in a DI diesel engine. The bowl geometry and dimensions, such as the pip region, bowl lip area, and toroidal radius, are all known to have an effect on the in-cylinder mixing and combustion processes. Based on the idea of enhancing diffusion combustion at the later stage of the combustion period, three different bowl geometries, namely, bowl 1 (baseline), bowl 2, and bowl 3 were selected and investigated. All the other relevant parameters, namely, compression ratio, maximum diameter of the bowl, squish clearance and injection rate were kept constant. A commercial CFD code STAR-CD was used to model the in-cylinder flows and combustion process, and experimental results of the baseline bowl were used to validate the numerical model. The simulation results show that, bowl 3 enhance the turbulence and hence results in better air-fuel mixing among all three bowls in a DI diesel engine. As a result, the indicated specific fuel consumption and soot emission reduced although the NOx emission is increased owing to better mixing and a faster combustion process. Globally, since the reduction in soot is larger (−46% as regards baseline) than the increase in NOx (+15% as regards baseline), it can be concluded that bowl 3 is the best trade-off between performance and emissions.

Numerical Simulation on Effect of Nozzle-Hole Layout on Spray Characteristics and Combustion in a DI Diesel Engine

2012 ◽  
Vol 476-478 ◽  
pp. 448-452
Author(s):  
Jun Zhang ◽  
Chang Pu Zhao ◽  
Nai Zhuan Chen ◽  
Da Lu Dong ◽  
Bo Zhong
Keyword(s):  
Numerical Simulation ◽  
Diesel Engine ◽  
Direct Injection ◽  
Combustion Process ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Spray Characteristics ◽  
Fuel Atomization ◽  
Di Diesel Engine ◽  
Nozzle Hole

Diesel spray characteristics are closely related to the combustion of the engine where the spray tip penetration and the fuel atomization play a key role especially for direct injection (DI) diesel engine. With different nozzles, the fuel atomization and evaporation will be different thereby affecting the combustion and emission characteristics. A three-dimensional model is built based on the parameters of a DI diesel engine, and its validation is also validated. Three nozzle-hole layouts are designed in this research, including the conventional hole, multi-hole, and group-hole. The spray characteristics and combustion process are studied with three different nozzle-hole layouts by the way of numerical simulation. Further more, the effect of inter-hole spacing of group-hole nozzle on the evaporation rate and combustion process is researched here.

Phenomenology of Smoke From Direct Injection Diesel Engine

2005 ◽  
Author(s):  
Y. V. Aghav ◽  
P. A. Lakshminarayanan ◽  
M. K. G. Babu ◽  
N. S. Nayak ◽  
A. D. Dani
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Operating Conditions ◽  
Turbulence Structure ◽  
One Dimensional ◽  
Direct Injection Diesel Engine ◽  
Wall Impingement ◽  
Di Diesel Engine ◽  
Dissipation Model ◽  
Wall Interaction

A phenomenological model for smoke prediction from a direct injection (DI) diesel engine is newly evolved from an eddy dissipation model of Dent [1]. The turbulence structure of fuel spray is developed by incorporating the wall impingement to explain smoke formed in free and wall portions. The spray wall interaction is unavoidable in case of modern DI diesel engines of bore less than 125 mm. The new model is one dimensional and based on the recent phenomenological description of spray combustion in direct injection diesel engine. Integration of net soot rate and no need to use empirical tuning constants are the important features, which distinguish the model from existing models. Smoke values are successfully predicted using this model for an engine with heavy-duty applications under widely varying operating conditions.

Investigating the Effect of Utilizing New Induction Manifold Designs on the Combustion Characteristics and Emissions of a Direct Injection Diesel Engine

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Mohamed A. Bassiony ◽  
Abdellatif M. Sadiq ◽  
Mohammed T. Gergawy ◽  
Samer F. Ahmed ◽  
Saud A. Ghani
Keyword(s):  
Diesel Engine ◽  
Peak Pressure ◽  
Direct Injection ◽  
Three Dimensional ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Maximum Pressure ◽  
Performance And Emissions ◽  
Di Diesel Engine ◽  
Dynamics Simulations

New induction manifold designs have been developed in this work to enhance the turbulence intensity and improve the mixing quality inside diesel engine cylinders. These new designs employ a spiral-helical shape with three different helical diameters (1D, 2D, 3D; where D is the inner diameter of the manifold) and three port outlet angles: 0 deg, 30 deg, and 60 deg. The new manifolds have been manufactured using three-dimensional printing technique. Computational fluid dynamics simulations have been conducted to estimate the turbulent kinetic energy (TKE) and the induction swirl generated by these new designs. The combustion characteristics that include the maximum pressure raise rate (dP/dθ) and the peak pressure inside the cylinder have been measured for a direct injection (DI) diesel engine utilizing these new manifold designs. In addition, engine performance and emissions have also been evaluated and compared with those of the normal manifold of the engine. It was found that the new manifolds with 1D helical diameter produce a high TKE and a reasonably strong induction swirl, while the ones with 2D and 3D generate lower TKEs and higher induction swirls than those of 1D. Therefore, dP/dθ and peak pressure were the highest with manifolds 1D, in particular manifold m (D, 30). Moreover, this manifold has provided the lowest fuel consumption with the engine load by about 28% reduction in comparison with the normal manifold. For engine emissions, m (D, 30) manifold has generated the lowest CO, SO2, and smoke emissions compared with the normal and other new manifolds as well, while the NO emission was the highest with this manifold.

Simulation Research on Post-Injection of Electronically Controlled Heavy-Duty Diesel Engine

2011 ◽  
Vol 121-126 ◽  
pp. 2238-2242
Author(s):  
Ming Hai Li ◽  
Feng Jiang ◽  
Biao Liu ◽  
Ming Gao Ouyang
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Process ◽  
Pressure Rise ◽  
Injection System ◽  
Post Injection ◽  
Simulation Research ◽  
Di Diesel Engine ◽  
Heavy Duty Diesel

GT-Suite software is used to establish the simulation model of electronic fuel injection system for 16V280ZJ diesel engine. Combustion process simulation calculation is conducted to the direct injection (DI) diesel engine based on a main-post double injection scheme. Simulation parameters are modified based on the comparison with given experimental results. The calculation results effectively reflect the influence of fuel ratio and the interval angle between main and post injection over emission and fuel economy. Finally, in order to improve the engine emissions and reduce the pressure rise rate, we get the optimal injection solution for the main-post injection mode.

scholarly journals Three dimensional modeling of combustion process and emission formation in a low heat rejection indirect injection diesel engine

2014 ◽  
Vol 18 (1) ◽  
pp. 53-65 ◽  
Author(s):  
S. Jafarmadar
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Three Dimensional ◽  
Heat Rejection ◽  
Full Load ◽  
Engine Efficiency ◽  
Three Dimensional Modeling ◽  
Full Load Operation ◽  
Computational Fluid Dynamics Cfd ◽  
Comparison Of The Results

Higher heat losses and brake specific fuel consumption (BSFC) are major problems in an indirect injection (IDI) diesel engine, which can be overcome by means of low heat rejection (LHR) concept. This concept is based on the approach of insulating of piston and liner of main chamber in IDI engine. At the present work, the combustion process and emission formation in baseline and LHR engines are studied by a Computational Fluid Dynamics (CFD) code at four different loads (25%, 50%, 75% and 100%) in maximum torque engine speed 730rpm. The numerical results for the pressure in cylinder and emissions for baseline engine at full load operation are compared to the corresponding experimental data and show good agreement. The comparison of the results for two cases show that when the load increases from 25% to 100% in 25% steps, heat loss in LHR engine decrease 40.3%, 44.7%,44.6% and 45.2%, respectively. At full load operation in LHR engine, NOx and Soot emissions decrease 13.5% and 54.4%, respectively and engine efficiency increases 6.3% in comparison to baseline engine.

scholarly journals Methodological Approach for 1D Simulation of Port Water Injection for Knock Mitigation in a Turbocharged DISI Engine

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4297
Author(s):  
Federico Millo ◽  
Fabrizio Gullino ◽  
Luciano Rolando
Keyword(s):  
Film Formation ◽  
Methodological Approach ◽  
Direct Injection ◽  
Water Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Transient Phenomena ◽  
Wall Film ◽  
The Impact

In the upcoming years, more challenging CO2 emission targets along with the introduction of more severe Real Driving Emissions limits are expected to foster the development and the exploitation of innovative technologies to further improve the efficiency of automotive Spark Ignition (SI) engines. Among these technologies, Water Injection (WI), thanks to its knock mitigation capabilities, can represent a valuable solution, although it may significantly increase the complexity of engine design and calibration. Since, to tackle such a complexity, reliable virtual development tools seem to be mandatory, this paper aims to describe a quasi-dimensional approach to model a Port Water Injection (PWI) system integrated in a Turbocharged Direct Injection Spark Ignition (T-DISI) engine. Through a port-puddling model calibrated with 3D-CFD data, the proposed methodology was proven to be able to properly replicate transient phenomena of water wall film formation, catching cycle by cycle the amount of water that enters into the cylinder and is therefore available for knock mitigation. Moreover, when compared with experimental measurements under steady state operating conditions, this method showed good capabilities to predict the impact of the water content on the combustion process and on the knock occurrence likelihood.

scholarly journals The Effect of RME-1-Butanol Blends on Combustion, Performance and Emission of a Direct Injection Diesel Engine

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2941
Author(s):  
Wojciech Tutak ◽  
Arkadiusz Jamrozik ◽  
Karol Grab-Rogaliński
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Direct Injection ◽  
Specific Energy Consumption ◽  
Combustion Process ◽  
Constant Load ◽  
Combustion Stability ◽  
Performance And Emission ◽  
Energy Share ◽  
The Stability

The main objective of this study was assessment of the performance, emissions and combustion characteristics of a diesel engine using RME–1-butanol blends. In assessing the combustion process, great importance was placed on evaluating the stability of this process. Not only were the typical COVIMEP indicators assessed, but also the non-burnability of the characteristic combustion stages: ignition delay, time of 50% heat release and the end of combustion. The evaluation of the combustion process based on the analysis of heat release. The tests carried out on a 1-cylinder diesel engine operating at a constant load. Research and evaluation of the combustion process of a mixture of RME and 1-butanol carried out for the entire range of shares of both fuels up to 90% of 1-butanol energetic fraction. The participation of butanol in combustion process with RME increased the in-cylinder peak pressure and the heat release rate. With the increase in the share of butanol there was noted a decrease in specific energy consumption and an increase in engine efficiency. The share of butanol improved the combustion stability. There was also an increase in NOx emissions and decrease in CO and soot emissions. The engine can be power by blend up to 80% energy share of butanol.

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