CFD Simulation to Understand Auto-Ignition Characteristics of Dual Fuel Strategies using High- and Low-Octane Fuels: A Step Towards The Octane-On-Demand Engine

2017 ◽  
Author(s):  
Rajesh Kumar ◽  
Olivier Laget ◽  
Guillaume Pilla ◽  
Guillaume Bourhis ◽  
Roland Dauphin ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Dual Fuel ◽  
On Demand ◽  
Auto Ignition ◽  
Ignition Characteristics

Development of a Numerical Model for Ignition Phenomena in a Micro Pilot Ignited Dual Fuel Engine With External Mixture Formation

2017 ◽  
Author(s):  
Michael Schiffner ◽  
Marcus Grochowina ◽  
Thomas Sattelmayer
Keyword(s):  
Flame Propagation ◽  
Ignition Delay ◽  
Cfd Simulation ◽  
Injection Pressure ◽  
Optical Measurements ◽  
Effect Of Temperature ◽  
Dual Fuel ◽  
Ignition Process ◽  
Fuel Blend ◽  
Auto Ignition

In this paper, a numerical investigation of the ignition process of dual fuel engines is presented. Optical measurements revealed that a homogeneous natural gas charge ignited by a small diesel pilot comprises the combustion phenomena of compression ignition of the pilot fuel as well as premixed flame propagation. The 3-Zones Extended Coherent Flame Model (ECFM3Z) was selected, since it can treat auto-ignition, pre-mixed flame propagation and diffusion flame aspects. Usually combustion models in multi-dimensional computational fluid dynamics (CFD) software packages are designed to handle only one reactive species representing the fuel concentration. In the context of the ECFM3Z model the concept of a multi-component fuel is applied to dual fuel operation. Since the available ignition models were not able to accurately describe the ignition characteristics of the investigated setup, a new dual fuel auto-ignition model was developed. Ignition delay times of the fuel blend are tabulated using a detailed reaction mechanism for n-heptane. Thereby, the local progress of pre-ignition reactions in the CFD simulation can be calculated. The ignition model is validated against experiments conducted with a periodically chargeable constant volume combustion chamber. The proposed model is capable to reproduce the ignition delay as well as the location of the flame kernels. The CFD simulations show the effect of temperature stratification and variations in the injection pressure on the apparent ignition delay of the micro pilot.

scholarly journals Effects of Gasoline-Diesel Ratio on Combustion and Emission Characteristics of a Dual-Fuel CI Engine: A CFD Simulation

2021 ◽  
Author(s):  
Kazi Mostafijur Rahman ◽  
Md. Habibur Rahaman
Keyword(s):  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Dual Fuel ◽  
Ignition Process ◽  
Unburned Hydrocarbon ◽  
Auto Ignition ◽  
Combustion Duration ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Rate Of Heat Release

Recently, considerable efforts are made by the engine researches all over the world, focusing primarily on achieving ultra-low emissions of NOx (nitrogen oxides) and soot without any compromise to high thermal efficiency from dual-fuel engine. In this study, combustion performance and engine-out emission of a single cylinder gasoline-diesel dual-fuel engine are numerically investigated by employing a commercial computation fluid dynamics (CFD) software, especially developed for internal combustion engines modeling. Here, gasoline-diesel relative ratio has been varied to find its impacts on performance of a dual-fuel engine. The results show that, in-cylinder pressure, in-cylinder temperature and rate of heat release (ROHR) are increased with gradual increment in diesel relative to gasoline. Injecting higher amount of diesel directly inside the combustion chamber as pilot fuel might have facilitated the auto-ignition process by reducing the ignition delay and accelerated the premixed gasoline-air flame propagation. These led to shorter main combustion duration which is quite desirable to suppress the knock in dual-fuel engines. In addition, NOx emission is found to decrease with relatively higher percentage of diesel. On the other hand, with increasing gasoline ratio relative to diesel, combustion duration is prolonged significantly and led to incomplete combustion, thereby increasing unburned hydrocarbon (UHC) and carbon monoxide (CO).

Feasibility Study of an On-Board Natural Gas to DME Reactor for DME Pre-Injection and Enhanced Ignition

2002 ◽  
Author(s):  
David Horstman ◽  
Duane Abata ◽  
Jason Keith ◽  
Leroy Oberto
Keyword(s):  
Natural Gas ◽  
Feasibility Study ◽  
Thermal Efficiency ◽  
Combustion Efficiency ◽  
Synthesis Process ◽  
Dual Fuel ◽  
Combined System ◽  
Auto Ignition ◽  
Ignition Characteristics ◽  
Ci Engines

Dual fuel (CI) engines provide an excellent means of maintaining high thermal efficiency and power while reducing emissions. This is particularly true in situations where the main CI fuel does not exhibit good auto-ignition characteristics, such as diesel engines operating on natural gas usually in stationary applications such as a pipeline installation. This paper explores the feasibility of chemically synthesizing DME from natural gas ‘on-board’ and using it as an ignition source for a dual fuel engine. Assuming a 5% pilot amount, a ‘once through’ process has been modeled and a first law analysis (using practical isentropic efficiencies) demonstrates that this combined system can be operated with a reduction of between 5–10% of the equivalent diesel efficiency. Significant quantities (∼30 vol.%) of hydrogen are introduced to the natural gas as a byproduct of the DME synthesis process. The corresponding increase in combustion efficiency must be validated by experiments to determine DME and H2 requirements for successful pilot ignition of the natural gas/H2 mixture.

scholarly journals Ignition characteristics of dual-fuel methane-n-hexane-oxygen-diluent mixtures in a rapid compression machine and a shock tube

Fuel ◽  
2019 ◽  
Vol 249 ◽  
pp. 379-391 ◽  
Author(s):  
Yizhuo He ◽  
Yingdi Wang ◽  
Claire Grégoire ◽  
Urszula Niedzielska ◽  
Remy Mével ◽  
...  
Keyword(s):  
Shock Tube ◽  
Dual Fuel ◽  
Rapid Compression Machine ◽  
Rapid Compression ◽  
Ignition Characteristics

Molecular Structure of Hydrocarbons and Auto-Ignition Characteristics of HCCI Engines

2014 ◽  
Vol 7 (3) ◽  
pp. 1050-1061 ◽  
Author(s):  
Gen Shibata ◽  
Ryota Kawaguchi ◽  
Soumei Yoshida ◽  
Hideyuki Ogawa
Keyword(s):  
Molecular Structure ◽  
Auto Ignition ◽  
Hcci Engines ◽  
Ignition Characteristics

Effects of water vapor on auto-ignition characteristics and laminar flame speed of methane/air mixture under engine-relevant conditions

Fuel ◽  
2022 ◽  
Vol 315 ◽  
pp. 123169
Author(s):  
Zhipeng Yuan ◽  
Linming Xie ◽  
Xingyu Sun ◽  
Rumin Wang ◽  
Huaqin Li ◽  
...  
Keyword(s):  
Water Vapor ◽  
Laminar Flame ◽  
Flame Speed ◽  
Laminar Flame Speed ◽  
Auto Ignition ◽  
Ignition Characteristics

Auto-ignition characteristics of methane/n-heptane mixtures under carbon dioxide and water dilution conditions

2020 ◽  
Vol 278 ◽  
pp. 115639
Author(s):  
Zhen Gong ◽  
Liyan Feng ◽  
Wenjing Qu ◽  
Lincheng Li ◽  
Lai Wei
Keyword(s):  
Carbon Dioxide ◽  
Auto Ignition ◽  
Ignition Characteristics ◽  
Water Dilution

Controlled auto-ignition characteristics of methane–air mixture in a rapid intake compression and expansion machine

Energy ◽  
2010 ◽  
Vol 35 (10) ◽  
pp. 4184-4191 ◽  
Author(s):  
Gyubaek Cho ◽  
Dongsoo Jeong ◽  
Gunfeel Moon ◽  
Choongsik Bae
Keyword(s):  
Auto Ignition ◽  
Compression And Expansion ◽  
Ignition Characteristics ◽  
Rapid Intake
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