3D-CFD Simulation of Diesel and Dual Fuel Engine Combustion

2007 ◽  
Author(s):  
Chengke Liu ◽  
G. A. Karim
Keyword(s):  
Cfd Simulation ◽  
Fuel Injection ◽  
Combustion Process ◽  
Dual Fuel ◽  
Injection Timing ◽  
Combustion Chambers ◽  
Detailed Chemical Kinetics ◽  
Swirl Chamber ◽  
Dual Fuel Engines ◽  
Combustion Processes

A 3D-CFD model with a reduced detailed chemical kinetics of the combustion of diesel and methane fuels is developed while considering turbulence during combustion to simulate the mixture flow, formation and combustion processes within diesel and diesel/methane dual fuel engines having swirl chambers. The combustion characteristics of the pilot injection into a small pre-chamber are also investigated and compared with those within a swirl chamber. Modeling results were validated by a group of corresponding experimental data. The spatial and temporal distributions of the mixture temperature, pressure and velocity under conditions with and without liquid fuel injection and combustion are compared in the swirl and main combustion chambers. The effects of engine speed, injection timing, and the addition of carbon dioxide on the combustion process of dual fuel engines are investigated. It is found that in the absence of any fuel injection and combustion, the swirl center is initially formed at the bottom left of the swirl chamber, and then moved up with continued compression in the top-right direction toward the highest point. The swirling motion within the swirl and main combustion chambers promotes the evaporation of the liquid pilot and the combustion processes of diesel and dual fuel engines. It was observed that an earlier autoignition can be obtained through injecting the pilot fuel into the small prechamber compared to the corresponding swirl chamber operation. It is to be shown that reduced engine emissions and improved thermal efficiency can be achieved by two-stage HCCI combustion.

Three-Dimensional Computational Fluid Simulation of Diesel and Dual Fuel Engine Combustion

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Chengke Liu ◽  
G. A. Karim
Keyword(s):  
Fuel Injection ◽  
Combustion Process ◽  
Fluid Simulation ◽  
Dual Fuel ◽  
Injection Timing ◽  
Detailed Chemical Kinetics ◽  
Mixture Flow ◽  
Swirl Chamber ◽  
Dual Fuel Engines ◽  
Combustion Processes

A 3D computational fluid dynamics model with a reduced detailed chemical kinetics of the combustion of diesel and methane fuels is developed while considering turbulence during combustion to simulate the mixture flow, formation, and combustion processes within diesel and diesel/methane dual fuel engines having swirl chambers. The combustion characteristics of the pilot injection into a small prechamber are also investigated. Modeled results were validated by a group of corresponding experimental data. The spatial and temporal distributions of the mixture temperature, pressure, and velocity under conditions with and without liquid fuel injection and combustion are compared. The effects of engine speed, injection timing, and the addition of carbon dioxide on the combustion process of dual fuel engines are investigated. It is found that in the absence of any fuel injection and combustion, the swirl center is initially formed at the bottom-left of the swirl chamber, and then moved up with continued compression in the top-right direction toward the highest point. The swirling motion within the swirl and main combustion chambers promotes the evaporation of the liquid pilot and the combustion processes of diesel and dual fuel engines. It was observed that an earlier autoignition can be obtained through injecting the pilot fuel into the small prechamber compared with the corresponding swirl chamber operation. It is to be shown that reduced engine emissions and improved thermal efficiency can be achieved by a two-stage homogenous charge compression ignition combustion.

Knock Prediction in Industrial Dual Fuel Engines Using a Two-Zone Combustion Model With Consideration of Chemical Kinetics

2008 ◽  
Author(s):  
Ahmed Al-Sened ◽  
Hesameddin Safari ◽  
Mojtaba Keshavarz ◽  
Ghasem Javadirad
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Chemical Reactivity ◽  
Gaseous Fuel ◽  
Combustion Model ◽  
Dual Fuel ◽  
Injection Timing ◽  
Boost Pressure ◽  
Fuel Mass ◽  
Dual Fuel Engines

Knock is well recognized as a destructive phenomenon to be avoided when running dual fuel engines. Typically, it occurs at high loads and high ambient temperatures and its onset has always been difficult to predict, particularly where multiple fuels are present. In a dual fuel engine, knock can occur from either the diesel or the gaseous fuel and it is recognised that the ratio of diesel fuel mass to gaseous fuel mass is an important index in determining which type of knock is predominant. This paper describes the development of a two-zone predictive model for the onset of knock in a dual fuel engine. Prediction of spark knock onset is the main objective of present work. A 9-step short mechanism with 11 chemical species, developed specifically for modelling dual fuel operation, is used to determine the chemical reactivity of the end-gas zone. The contribution of pilot diesel fuel combustion is taken into account by a heat release model. Chemical equilibrium is assumed for the burned gas zone. Simulation results predict the point of knock-limited BMEP and its dependency on operating parameters such as air intake temperature, boost pressure, start of pilot fuel injection timing and compression ratio. The results were first validated against some published engine analysis data and also some in-house performance prediction data. Secondly, a known dual-fuel development engine was simulated. Finally, the performance of an engine which had been converted from diesel to dual fuel during its service life was modeled but commercial constraints prevent the identification of this engine within this paper. However, good agreement with existing performance data was demonstrated in all these cases.

scholarly journals An Investigation of the Effect of Fuel Supply Parameters on Combustion Process of the Heavy-Duty Dual-Fuel Diesel Ignited Gas Engine

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2280 ◽  
Author(s):  
Andrey Kozlov ◽  
Vadim Grinev ◽  
Alexey Terenchenko ◽  
Gennady Kornilov
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Combustion Process ◽  
Injection Pressure ◽  
Dual Fuel ◽  
Injection Timing ◽  
Fuel Supply ◽  
Pilot Fuel ◽  
Fuel Injection Pressure

Modern research in the area of internal combustion engines is focused on researching and investigating the technologies that will improve fuel efficiency and decrease emissions. Application of dual-fuel engines is considered as a potential solution to these problems. In the dual-fuel engine, a natural gas-air mixture is ignited by a small amount of the diesel fuel directly injected into a combustion chamber. Pilot fuel injection parameters can strongly effect the combustion process. The aim of this paper is to investigate the effect of such fuel-supply parameters as pilot fuel mass, pilot fuel injection pressure, pilot fuel injection timing and excess air ratio on the combustion process. Investigation is based on the data obtained during bench tests conducted with the use of measurement equipment. The dependences of engine characteristics from the fuel supply parameters under review were obtained based on the results of the experimental study. Optimal values for every investigated fuel-supply parameter were chosen based on the obtained results. Over the course of the investigation, the coefficient for heat release rate according to the Vibe equation was calculated for each operating point.

scholarly journals A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1342
Author(s):  
Van Chien Pham ◽  
Jae-Hyuk Choi ◽  
Beom-Seok Rho ◽  
Jun-Soo Kim ◽  
Kyunam Park ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Simulation Software ◽  
Dual Fuel ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Cylinder Pressure ◽  
Marine Engine ◽  
Full Load ◽  
Simulation Results

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

A phenomenological combustion analysis of a dual-fuel natural-gas diesel engine

2016 ◽  
Vol 231 (1) ◽  
pp. 66-83 ◽  
Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Heat Release ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Dual Fuel ◽  
Injection Timing ◽  
Heavy Duty ◽  
Engine System ◽  
Wiebe Function

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.

Simulation Research on Combustion Process in a Natural Gas-Diesel Dual-Fuel Marine Engine

2014 ◽  
Vol 525 ◽  
pp. 227-231 ◽  
Author(s):  
Min Xiao ◽  
Chun Long Feng
Keyword(s):  
Natural Gas ◽  
Total Energy ◽  
Combustion Process ◽  
Power Reduction ◽  
Dual Fuel ◽  
Injection Timing ◽  
Simulation Research ◽  
Injection Duration ◽  
Medium Speed ◽  
The Right

In order to solve the problem of Diesel natural gas dual fuel engine, such as power reduction, low charging efficiency, the conception of diesel engine fueled with pilot-ignited directly-injected liquefied natural gas is put forward. On the basis of this theory, a medium speed diesel of the marine is refitted into dual fuel engine, in order to keep original power, decrease the temperature of combustion and reduce emission. The LNG injection timing, duration of LNG injection and the different ratios the pilot diesel to total energy are studied the method of AVL FIRE software. Conclusions are as follows: When the different ratios pilot diesel to total energy is 0.5%, the engine can not work; Delaying the LNG injection timing, shortening the LNG injection duration and choose the right ratios pilot diesel to total energy can reach the indicated power of original machine, and the NOx emissions level will be greatly reduced.

CFD Modelling of the Effects of Injection Timing on the Combustion Process and Emissions in an HSDI Diesel Engine

2012 ◽  
Author(s):  
Raouf Mobasheri ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Timing ◽  
Cfd Modelling ◽  
Combustion Modeling ◽  
Pressure Trace ◽  
Hsdi Diesel Engine

High-Speed Direct Injection (HSDI) diesel engines are increasingly used in automotive applications due to superior fuel economy. An advanced CFD simulation has been carried out to analyze the effect of injection timing on combustion process and emission characteristics in a four valves 2.0L Ford diesel engine. The calculation was performed from intake valve closing (IVC) to exhaust valve opening (EVO) at constant speed of 1600 rpm. Since the work was concentrated on the spray injection, mixture formation and combustion process, only a 60° sector mesh was employed for the calculations. For combustion modeling, an improved version of the Coherent Flame Model (ECFM-3Z) has been applied accompanied with advanced models for emission modeling. The results of simulation were compared against experimental data. Good agreement of calculated and measured in-cylinder pressure trace and pollutant formation trends were observed for all investigated operating points. In addition, the results showed that the current CFD model can be applied as a beneficial tool for analyzing the parameters of the diesel combustion under HSDI operating condition.

Sign in / Sign up

Export Citation Format

Share Document