scholarly journals Influence of Fuel System Variations on Performance and Emission Characteristics of Combined Air-Wall Guided Mode Modified GDI engine with Alcoholic Fuels and Exhaust Gas Recirculation

Author(s):  
Shivakumar Nagareddy ◽  
Kumaresan Govindasamy

Abstract GDI engines commercially existed with spray guided mode where the fuel injector placed almost vertically and sprayed fuel is occupied throughout the volume of combustion chamber. With the advanced emission norms, NOx and Soot emissions control is the major task along with lower fuel consumption. To achieve the advanced emission norms, further modifications are required before or during combustion. Combined air-wall guided mode combustion chamber modification is the advanced stage required for further improvement in mixing and superior combustion. Air-wall combined mode involved piston crown shape modification so that the modified shape should impart turbulence effects and divert the fuel/mixture flow towards the spark plug tip to initiate the combustion process. In this study, the combined air-wall guided mode gasoline direct injection engine was tested with gasoline blends using Ethanol, Methanol and N-Butanol at 20, 35 and 50% proportions under specific fixed conditions: 1500 rpm speed, 10% EGR and FIP of 150 bars with three split injections at 320˚, 220˚ and 100˚ before TDC. Tests were conducted over these gasoline blend proportions for engine performance and emission characteristics and achieved beneficial results with E20 gasoline blend over the entire applied torque values.

2021 ◽  
pp. 358-358
Author(s):  
Shivakumar Nagareddy ◽  
Kumaresan Govindasamy

In this study, the combustion chamber geometry for spray-guided, wall-guided, and air-guided combustion strategies were fabricated. The piston crown shape and the cylinder head in each combustion chamber geometry was machined by fixing the fuel injector and spark plug at proper positions to obtain swirl, turbulence, and squish effects for better mixing of fuel with air and superior combustion of the mixture. Conducted tests on all the three modified gasoline direct injection engines with optimized exhaust gas recirculation and electronic control towards fuel injection timing, the fuel injection pressure, and the ignition timing for better the performance and emissions control. It is clear from the results that NOx emissions from all three combustion modes were reduced by 4.9% upto 50% of loads and it increase for higher loads due to increase of in-cylinder pressure. The fuel consumption and emissions showed better at 150 bar Fuel Injection Pressure for wall-guided combustion chamber geometry. Reduced HC emissions by 3.7% and 4.7%, reduced CO emissions by 2% and 3.3%, reduced Soot emissions by 6.12% and 10.6%. Reduces specific fuel consumption by about 10.3% and 13.3% in wall-guided combustion strategy compare with spray-guided and air-guided combustion modes respectively.


Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating

Abstract Numerical simulation of flow, combustion, heat release rate and pollutants emission characteristics have been obtained using a single cylinder internal combustion engine operating with propane as the fuel. The data are compared with experimental results and show excellent agreement for peak pressure and the rate of pressure rise as a function of crank angle. The results obtained for NO and CO are also found to be in good agreement and are similar to those reported in the literature for the chosen combustion chamber geometry. The results have shown that both the combustion chamber geometry and engine operating parameters affects the flame growth within the combustion chamber which subsequently affects the pollutants emission levels. The code employed the time marching procedure and solves the governing partial differential equations of multi-component chemically reacting fluid flow by finite difference method. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.


In this world, the population is increased and the number of vehicles increased. Not only population the pollution is increased lot by vehicles in the world harmful pollutant is realized from the vehicles like CO, HC, NOx and smoke particulates. It is inevitable to find some new technology, which increases the better performance and emission characteristics. Partially premixed compression ignition (PCCI) is the best technology for the reducing of harmful pollution in the vehicle, which uses the diesel as fuel it, gives the advantages of both CI and SI engine. This paper investigates the performance and emission characteristics of partially premixed diesel engine. Diesel engine has two injectors of port fuel injector (PFI) and direct injector (DI) to inject the fuel in different timing and electrical control unit (ECU) passes the power to PFI; it can control the injection timing and increases the fuel content from the fuel pump. The main aim in this paper is studied is effect of partially premixed ratio, performance of engine and emission characteristics of diesel engine


2019 ◽  
Vol 21 (8) ◽  
pp. 1520-1540 ◽  
Author(s):  
Ankit A Raut ◽  
J M Mallikarjuna

In-cylinder water injection is a promising approach for reducing NOx and soot emissions from internal combustion engines. It allows one to use a higher compression ratio by reducing engine knock; hence, higher fuel economy and power output can be achieved. However, water injection can also affect engine combustion and emission characteristics if water injection and injector parameters are not properly set. Majority of the previous studies on the water injection are done through experiments. Therefore, subtle aspects of water injection such as in-cylinder interaction of water sprays, spatial distribution of water vapor, and effect on flame propagation are not clearly understood and rarely reported in literature due to experimental limitations. Thus, in the present article, a computational fluid dynamics investigation is carried out to analyze the effects of direct water injection under various injector configurations on water evaporation, combustion, performance, and emission characteristics of a gasoline direct injection engine. The emphasis is given to analyze in-cylinder water spray interactions, flame propagation, water spray droplet size distribution, and water vapor spatial distribution inside the engine cylinder. For the study, the water-to-fuel ratio is varied from 0 to 1. Various water injector configurations using nozzle hole diameters of 0.14, 0.179, and 0.205 mm, along with nozzle holes of 4, 5, 6, and 7, are considered for comparison in addition to the case of no_water. Computational fluid dynamics models used in this study are validated with the available data in literature. From the results, it is found that the emission and performance characteristics of the engine are highly dependent on water evaporation characteristics. Also, the water-to-fuel ratio of 0.6 with 6 number of nozzle holes and the nozzle diameter of 0.14 mm results in the highest indicated mean effective pressure and the lowest NOx, soot, and CO emissions compared to other cases considered.


2014 ◽  
Vol 984-985 ◽  
pp. 900-906
Author(s):  
L. Saravanakumar ◽  
B.R. Ramesh Bapu ◽  
B. Durga Prasad

The present work investigates the effect of change in combustion chamber geometry on performance and emission characteristics of single cylinder diesel engine fuelled with mahua biodiesel. Since plant oil derived from the mahua tree has high fatty acids, it undergoes esterification followed by transesterification process to reduce its viscosity. Experiments were conducted using a blend of 20% biodiesel (B20) 40% biodiesel (B40) with diesel and compared with diesel by using two types of combustion chamber geometry, explicitly hemispherical and modified hemispherical combustion chamber. Performance parameters such as Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC) and emission parameters like Unburned Hydro Carbon (UBHC), Oxides of Nitrogen (NOx) were studied from the diesel engine with above mentioned configurations. It is obvious that there is considerable improvement in the performance parameter viz, BTE, BSFC and reduction in UBHC emissions by using the modified geometry piston. However, the NOx emission was found to be higher than that of standard configuration. The results obtained from the blend B20 at modified combustion chamber geometry are on par with diesel and hence mahua biodiesel can be suggested as an alternative fuel for Compression Ignition (C.I) engine with modified combustion chamber geometry.


2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Chidambaram Kannan ◽  
Thulasi Vijayakumar

Homogeneous combustion has the potential of achieving both near-zero emissions and low specific fuel consumption. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions, and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In this research work, a highly porous ceramic structure was introduced into the combustion chamber (underside of the cylinder head). The influence of operating parameters such as exhaust gas recirculation (EGR) and injection timing on the combustion, performance, and emission characteristics of such developed engine was investigated in this research work.


Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu

Abstract The conversion of existing diesel engines to spark ignition (SI) operation by adding a low-pressure injector in the intake manifold for fuel delivery and replacing the original high-pressure fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and increase natural gas (NG) applications in heavy-duty transportation sectors. Since the conventional diesel combustion chamber (i.e., flat-head-and-bowl-in-piston-chamber) creates high turbulence, the converted NG SI engine can operate leaner with stable and repeatable combustion process. However, existing literatures point to a long late-combustion duration and increased unburned hydrocarbon emissions in such retrofitted engines that maintained the original combustion chamber. Consequently, the main objective of this paper was to report recent findings of NG combustion characteristics inside a bowl-in-piston combustion chamber that will add to the general understanding of the phenomena. The new results indicated that the premixed NG burn inside the bowl-in-piston combustion chamber will separate into a bowl-burn and a squish-burn processes in terms of burning location and timing. The slow burning event in the squish region explains the low slope of the burn rate towards the end of combustion in existing studies (hence the longer late-combustion period). In addition, the less-favorable conditions for the combustion in the squish region explained the increased carbon monoxide and unburned hydrocarbon emissions.


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