A Phenomenological Model for Predicting Entropy Generation during Vaporization of Droplets in Engine Fuel Sprays

2014 ◽  
Vol 592-594 ◽  
pp. 1403-1407
Author(s):  
Ismail Saleel ◽  
Pramod S. Mehta
Keyword(s):  
Entropy Generation ◽  
Phenomenological Model ◽  
Fuel Injection ◽  
Engine Performance ◽  
Hydrocarbon Fuel ◽  
Combustible Mixture ◽  
Engine Fuel ◽  
Fuel Droplets ◽  
Performance And Emissions ◽  
Injection Techniques

Modern internal combustion (IC) engines employ a variety of injection techniques for preparing a combustible mixture of fuel and air. In a fuel injection-based system, the vaporization of the atomized hydrocarbon fuel droplets has significant influence on engine performance and emissions. The entropy generation associated with droplet vaporization is particularly important as it is directly related to the destruction of exergy i.e. the potential to produce useful work. Since a fuel spray could involve millions of droplets, solving the entire set of governing equations for individual droplets in a spatiotemporally discretized domain is impractical. The present work explores the utility of a simple phenomenological model in predicting the entropy generation history. The results indicate that this model ensures computational efficiency without much sacrifice in accuracy.

scholarly journals Comparison of the Emissions, Noise, and Fuel Consumption Comparison of Direct and Indirect Piezoelectric and Solenoid Injectors in a Low-Compression-Ratio Diesel Engine

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4023 ◽  
Author(s):  
Stefano d’Ambrosio ◽  
Alessandro Ferrari ◽  
Alessandro Mancarella ◽  
Salvatore Mancò ◽  
Antonio Mittica
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Injection ◽  
Engine Performance ◽  
Combustion Noise ◽  
Driving System ◽  
Performance And Emissions ◽  
Direct Acting ◽  
Engine Performance And Emissions

An experimental investigation has been carried out to compare the performance and emissions of a low-compression-ratio Euro 5 diesel engine featuring high EGR rates, equipped with different injector technologies, i.e., solenoid, indirect-acting, and direct-acting piezoelectric. The comparisons, performed with reference to a state-of-the-art double fuel injection calibration, i.e., pilot-Main (pM), are presented in terms of engine-out exhaust emissions, combustion noise (CN), and fuel consumption, at low–medium engine speeds and loads. The differences in engine performance and emissions of the solenoidal, indirect-acting, and direct-acting piezoelectric injector setups have been found on the basis of experimental results to mainly depend on the specific features of their hydraulic circuits rather than on the considered injector driving system.

Effect of Non-Isothermal Conditions on Liquid Breakup Mechanisms

2010 ◽  
Author(s):  
Ilai Sher
Keyword(s):  
Physical Properties ◽  
Fuel Injection ◽  
Thermal Exposure ◽  
Ambient Air ◽  
Combustible Mixture ◽  
Liquid Droplets ◽  
Gas Temperature ◽  
Fuel Droplets ◽  
Breakup Mechanism ◽  
Secondary Breakup

Liquid breakup mechanism utilization is prevalent in numerous applications. One of the most common uses of this phenomenon is in fuel injection systems. Liquid fuel is injected into an ambient air, to prepare a combustible mixture. Generally, evenly spread tiny fuel droplets are desirable. This is usually achieved through multiple liquid breaking mechanisms: Primary breakup of liquid jet, Secondary breakup of travelling liquid droplets, and Secondary breakup of wall-impinging liquid droplets. Indeed, many studies are devoted to the modelling of those phenomena. However, the absolute majority of those studies are limitedly focused on the isothermal case, where liquid is assumed to be of ambient gas’ temperature. Conversely, practical conditions, under which rather cold fuel is normally injected into hot ambient air, suggest the real case to be non-isothermal. Moreover, the non-isothermal nature of that process seems to have its effect at the most relevant to breakup regions, i.e. the breaking interfacial surfaces. It is shown that as these surfaces can be in instant contact with a hot ambient, breakup can be greatly altered by the extent of this sudden thermal exposure, through its mostly transient and even spatial effect on physical properties of breaking interfaces. This is shown to be of significant effect on all breakup mechanisms: primary and secondary. New models are suggested for these non-isothermal phenomena, which combine transient heat-transfer with inter-phase hydrodynamic breakup, through physical properties’ dependency on temperature. Results are discussed in terms of effect on spray breakup products, and a careful comparison with the trend of a limited number of so-far available experimental results is presented.

scholarly journals Experimental Comparative Study on Performance and Emissions of E85 Adopting Different Injection Approaches in a Turbocharged PFI SI Engine

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1555 ◽  
Author(s):  
Cinzia Tornatore ◽  
Luca Marchitto ◽  
Maria Antonietta Costagliola ◽  
Gerardo Valentino
Keyword(s):  
Fuel Injection ◽  
Reference Conditions ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Intake Manifold ◽  
Si Engine ◽  
Spark Timing ◽  
Performance And Emissions ◽  
Ethanol Blends ◽  
Cylinder Port

This study examines the effects of ethanol and gasoline injection mode on the combustion performance and exhaust emissions of a twin cylinder port fuel injection (PFI) spark ignition (SI) engine. Generally, when using gasoline–ethanol blends, alcohol and gasoline are externally mixed with a specified blending ratio. In this activity, ethanol and gasoline were supplied into the intake manifold into two different ways: through two separated low pressure fuel injection systems (Dual-Fuel, DF) and in a blend (mix). The ratio between ethanol and gasoline was fixed at 0.85 by volume (E85). The initial reference conditions were set running the engine with full gasoline at the knock limited spark advance boundary, according to the standard engine calibration. Then E85 was injected and a spark timing sweep was carried out at rich, stoichiometric, and lean conditions. Engine performance and gaseous and particle exhaust emissions were measured. Adding ethanol could remove over-fueling with an increase in thermal efficiency without engine load penalties. Both ethanol and charge leaning resulted in a lowering of CO, HC, and PN emissions. DF injection promoted a faster evaporation of gasoline than in blend, shortening the combustion duration with a slight increase in THC and PN emissions compared to the mix mode.

Effects of Different Biodiesel Blends on Heat Release and Its Related Parameters

2006 ◽  
Author(s):  
Girish Parvate-Patil ◽  
Manuel Vasquez ◽  
Malcolm Payne
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Fuel Injection ◽  
Load Condition ◽  
Engine Performance ◽  
Injection Pressure ◽  
Single Cylinder ◽  
Medium Speed ◽  
Performance And Emissions ◽  
Fuel Injection Pressure

This paper emphasizes on the effects of different biodiesels and diesel on; heat release, ignition delay, endothermic and exothermic reactions, NOx, fuel injection pressure due to the fuel’s modulus of elasticity and cylinder pressure. Two 100% biodiesel and its blends of 20% with of low sulfur #2 diesel, and #2 diesel are tested on a single cylinder diesel engine under full load condition. Engine performance and emissions data is obtained for 100% and 20% biodiesels blends and #2 diesel. Testes were conducted at Engine Systems Development Centre, Inc. (ESDC) to evaluate the effects of biodiesel and its blends on the performance and emissions of a single-cylinder medium-speed diesel engine. The main objective of this work was to gain initial information and experience about biodiesel for railway application based on which biodiesel and its blends could be recommended for further investigation on actual locomotives.

Paper 2: Similarity Considerations in Assessing Diesel Engine Fuel Spray Requirements

1965 ◽  
Vol 180 (14) ◽  
pp. 10-29 ◽  
Author(s):  
B. E. Knight
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Fuel Spray ◽  
Theoretical Expression ◽  
Engine Fuel ◽  
Wide Range ◽  
Air Mixing ◽  
Dimensionless Variables ◽  
Mixing Problem

A simplified dimensional analysis has been made of the fuel-air mixing problem in diesel engines. The dimensionless variables describing the mixing pattern have been expressed in terms of the dimensionless variables describing the engine and fuel injection conditions by means of explicit equations with numerical values for the constants. A wide range of such equations has been derived and tables of numerical values are given as examples, together with examples of engine air motion calculations for comparison. A theoretical expression for fuel-spray penetration into a cross-wind has been compared with a few experimental results. Engine smoke and specific consumption measurements have been plotted against the appropriate dimensionless variables in two instances. In both instances the response of the engine to the variables is quite different. It is believed that the wide range of methods of engine performance data analysis outlined in this paper will make a significant contribution to progress in understanding diesel engine combustion.

Improving the performance of a diesel engine by changing injectors characteristics after reduction on the compression ratio

2021 ◽  
Vol 15 (2) ◽  
pp. 8153-8168
Author(s):  
Saeed Chamehsara ◽  
Mohammadreza Karami
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Engine Performance ◽  
Combustion Engines ◽  
Fuel Injector ◽  
Start Time ◽  
Performance And Emissions ◽  
Nozzle Hole ◽  
The Impact

In order to repair internal combustion engines, sometimes it is necessary to replace the components of these engines with each other. Therefore changes in engine performance are inevitable in these conditions. In the present study, by changing the coneccting rod and the crank of the OM457 turbo diesel-fueled engine with the OM444, it was observed that the performance of the engine decreases. Numerical simulations have been carried out to study the Possible ways to mitigate this reduction. One way to achieve this goal is to change the fuel injector’s characteristics such as, fuel injector’s nozzle hole diameter, number of nozzle holes, and start time of fuel injection. In this study, the impact of these parameters on the performance and emissions of these engines were analyzed. Another scenario is an increase in inlet fuel and air by the same amount. The results indicate that By reducing the diameter of fuel injector holes and hole numbers, the performance of the engine was increased. on the other hand, the NOx emissions were increased while the amount of soot emission decreased. The same results were concluded by retarding the start time of injection. Subsequently, a case study of changing fuel injector parameters for mitigation of decreased performance was performed. These parameters were simultaneously applied, and results were compared. The performance of the engine with improved injector’s characteristics was close to the main OM457. Similar results were obtained by increasing the amount of inlet air and fuel.

scholarly journals Performance and Emissions Analysis of 4-Stroke Biodiesel Engine at Different Injection Pressure

2021 ◽  
Vol 9 (VI) ◽  
pp. 2361-2372
Author(s):  
Pal Vishal H.
Keyword(s):  
Alternative Fuels ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Engine Performance ◽  
Injection Pressure ◽  
Experimental Investigations ◽  
Biodiesel Fuel ◽  
Performance And Emissions ◽  
Fuel Injection Pressure ◽  
Carbon Dioxide Co2

Alternative fuels for diesel engines have become increasingly important due to several socioeconomic aspects, imminent depletion of fossil fuel and growing environmental concerns. Global warming concerns due to the production of greenhouse gases (GHGs) such as carbon dioxide (CO2) as results from internal combustion engine have seen as one of major factor the promotion of the use of biofuels. Therefore, the use of biodiesel fuel (BDF) as an alternative for fossil diesel (DSL) is among the effective way to reduce the CO2 emission. In this experimental study, the effects on engine performance and fuel-induced emission characteristics were studied using fuel blends and under different fuel injection pressure. Even though the brake thermal efficiency was obtained maximum for the conventional diesel at standard operating condition, the same can also be achieved with biodiesel blends by increasing the injection pressure higher than that of the level used for conventional diesel. This experimental test was done using a small 4-stroke single cylinder diesel engine with electric dynamometer loads integrated with emission gas analyser that attached to the exhaust pipeline. As results of experimental investigations, decreasing in NOX Emission, SOX Emission, CO Emission and also brake specific fuel consumption compare to pure diesel.

Assessment of gasoline direct injector fouling effects on fuel injection, engine performance and emissions

2018 ◽  
Vol 220 ◽  
pp. 351-374 ◽  
Author(s):  
Tawfik Badawy ◽  
Mohammadreza Anbari Attar ◽  
Hongming Xu ◽  
Akbar Ghafourian
Keyword(s):  
Fuel Injection ◽  
Engine Performance ◽  
Performance And Emissions ◽  
Engine Performance And Emissions
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