Flame Propagation in Natural Gas Fueled Direct Injection Engines

2010 ◽  
Author(s):  
Mark Fabbroni ◽  
James S. Wallace
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Heated Surface ◽  
Direct Injection ◽  
Direct Injection Engines ◽  
Glow Plug ◽  
Compression Device ◽  
Engine Combustion ◽  
Ignition Site

Injected natural gas requires some form of ignition assist in order to ignite in the time available in a diesel engine combustion chamber. A glow plug — a heated surface — is one form of ignition assist. Ignition by glow plug results in a single site of ignition from which the flame must propagate to other jets in the injection pattern. The goal of this work was to determine what factors affect how the flame propagates from this initial ignition site to the remaining unburned mixture site. The combustion of natural gas jets under diesel engine conditions was studied over a range to temperatures, pressures with and without a glow plug shield using a CFR engine as a rapid compression device. The results showed that of all the factors considered it is the geometry of the injection pattern, combustion chamber and glow plug shield that are most dominant in controlling combustion rates and fuel utilization.

Ignition by Shielded Glow Plug in Natural Gas Fueled Direct Injection Engines

2011 ◽  
Author(s):  
Mark Fabbroni ◽  
James S. Wallace
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Heated Surface ◽  
Direct Injection ◽  
Cylinder Wall ◽  
Fuel Utilization ◽  
Direct Injection Engines ◽  
Glow Plug ◽  
Gas Jets

Injected natural gas requires some form of ignition assist in order to ignite in the time available in a diesel engine combustion chamber. A glow plug — a heated surface — is one form of ignition assist. Ignition by glow plug results in a single site of ignition from which the flame must propagate to other jets in the ignition pattern. The goal of this work was to determine what factors affect how the flame propagates from this initial ignition site to the remaining unburned mixture. The combustion of natural gas jets under diesel engine conditions was studied over a range of temperatures with a glow plug shield using a CFR engine as a rapid compression device. The results showed that of all the factors considered it is the inter-related geometries of the injection pattern, combustion chamber, and glow plug shield that are most dominant in controlling combustion rates and fuel utilization, because those factors determine the distribution of fuel in the combustion chamber. Ignition of adjacent gas jets requires a flammable path between jets, which is achieved: 1) through mixing between the entrainment regions of adjacent jets and 2) through mixing along the cylinder wall of adjacent jets that are spreading along the wall. Ignition by either of both of these pathways can provide high fuel utilization and combustion rates and low combustion variability. Autoignition of an adjacent jet due to heat release from ignition of the first jet was not observed in these experiments with two jets.

Modeling of Ignition and Combustion for Glow Plug Assisted Direct Injection Natural Gas Engines

2012 ◽  
Author(s):  
Stewart Xu Cheng ◽  
James S. Wallace
Keyword(s):  
Natural Gas ◽  
Heated Surface ◽  
Direct Injection ◽  
Cfd Modeling ◽  
Spontaneous Ignition ◽  
Layer Model ◽  
Glow Plug ◽  
Natural Gas Engines ◽  
Gas Ignition ◽  
Ignition And Combustion

Direct injection natural gas (DING) engines offer the advantages of high thermal efficiency and high power output compared to spark ignition natural gas engines. Injected natural gas requires some form of ignition assist in order to ignite in the time available in a diesel engine combustion chamber. A glow plug — a heated surface — is one form of ignition assist. Simple experiments show that the thickness of the heat penetration layer of a glow plug is very small (≈10−5 m) within the time scale of the ignition preparation period (1–2 ms). Meanwhile, the theoretical analyses reveal that only a very thin layer of the surrounding gases (in micrometer scale) can be heated to high temperature to achieve spontaneous ignition. A discretized glow plug model and virtual gas sub-layer model have been developed for CFD modeling of glow plug ignition and combustion for DING diesel engines. In this paper, CFD modeling results are presented. The results were obtained using a KIVA3 code modified to include the above mentioned new developed models. Natural gas ignition over a bare glow plug was simulated. The results were validated against experiments. Simulation of natural gas ignition over a shielded glow plug was also carried out and the results illustrate the necessity of using a shield. This paper shows the success of the discretized glow plug model working together with the virtual gas sub-layer model for modeling glow plug assisted natural gas direct injection engines. The modeling can aid in the design of injection and ignition systems for glow plug assisted DING engines.

Transient Behavior of Glow Plugs in Direct-Injection Natural Gas Engines

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Stewart Xu Cheng ◽  
James S. Wallace
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Direct Injection ◽  
High Surface ◽  
Cold Start ◽  
Transfer Model ◽  
Ignition Process ◽  
Computational Domain ◽  
Glow Plug ◽  
Natural Gas Engines

Glow plugs are a possible ignition source for direct injected natural gas engines. This ignition assistance application is much different than the cold start assist function for which most glow plugs have been designed. In the cold start application, the glow plug is simply heating the air in the cylinder. In the cycle-by-cycle ignition assist application, the glow plug needs to achieve high surface temperatures at specific times in the engine cycle to provide a localized source of ignition. Whereas a simple lumped heat capacitance model is a satisfactory representation of the glow plug for the air heating situation, a much more complex situation exists for hot surface ignition. Simple measurements and theoretical analysis show that the thickness of the heat penetration layer is small within the time scale of the ignition preparation period (1–2 ms). The experiments and analysis were used to develop a discretized representation of the glow plug domain. A simplified heat transfer model, incorporating both convection and radiation losses, was developed for the discretized representation to compute heat transfer to and from the surrounding gas. A scheme for coupling the glow plug model to the surrounding gas computational domain in the KIVA-3V engine simulation code was also developed. The glow plug model successfully simulates the natural gas ignition process for a direct-injection natural gas engine. As well, it can provide detailed information on the local glow plug surface temperature distribution, which can aid in the design of more reliable glow plugs.

Analysis and Research of the Combustion Process of YN4100QB Diesel Engine

2013 ◽  
Vol 744 ◽  
pp. 35-39
Author(s):  
Lei Ming Shi ◽  
Guang Hui Jia ◽  
Zhi Fei Zhang ◽  
Zhong Ming Xu
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engine ◽  
Combustion Chamber ◽  
Optimization Design ◽  
Combustion Engine ◽  
Geometric Model ◽  
Combustion Process ◽  
Internal Combustion ◽  
Engine Combustion ◽  
Exhaust Noise

In order to obtain the foundation to the research on the Diesel Engine YN4100QB combustion process, exhaust, the optimal design of combustion chamber and the useful information for the design of exhaust muffler, the geometric model and mesh model of a type internal combustion engine are constructed by using FIRE software to analyze the working process of internal combustion engine. Exhaust noise is the main component of automobile noise in the study of controlling vehicle noise. It is primary to design a type of muffler which is good for agricultural automobile engine matching and noise reduction effect. The present car mufflers are all development means. So it is bound to cause the long cycle of product development and waste of resources. Even sometimes not only can it not reach the purpose of reducing the noise but also it leads to reduce the engine dynamic. The strength of the exhaust noise is closely related to engine combustion temperature and pressure. The calculation and initial parameters are applied to the software based on the combustion model and theory. According to the specific operation process of internal combustion engine. Five kinds of common operation condition was compiled. It is obtained for the detailed distribution parameters of combusted gas temperature pressure . It is also got for flow velocity of the fields in cylinder and given for the relation of the parameters and crankshaft angle for the further research. At the same time NOx emissions situation are got. The numerical results show that not only does it provide the 3D distribution data in different crank shaft angle inside the cylinder in the simulation of combustion process, but also it provides a basis for the engine combustion ,emission research, the optimization design of the combustion chamber and the useful information for the designs of muffler.

scholarly journals Mixedness Measurement in Gaseous Jet Injection

2017 ◽  
Author(s):  
Martia Shahsavan ◽  
John Hunter Mack
Keyword(s):  
Combustion Chamber ◽  
Direct Injection ◽  
Premixed Combustion ◽  
Working Fluid ◽  
Scalar Dissipation ◽  
Jet Injection ◽  
Direct Injection Engines ◽  
Comprehensive Method ◽  
Mixture Homogeneity ◽  
Crucial Parameter

In turbulent non-premixed combustion applications, such as diesel and direct injection engines, the mixedness of the injected fuel with oxygen and the working fluid inside the combustion chamber is a crucial parameter since it can significantly affect the ignition behavior. In this study, a comprehensive method for investigating mixedness, defined by spatial variation and scalar dissipation, is implemented to assess the turbulent injection of hydrogen into mixture of oxygen with nitrogen, argon, and xenon. Evaluating both criteria reflects the mixture homogeneity as well as local gradients, which aids in discriminating scalar distributions with identical homogeneity and different patterns. The results indicate that replacing nitrogen with argon as the working fluid can provide more suitable ignition conditions for the hydrogen jet.

scholarly journals Effect of combustion chamber geometry on performance, combustion, and emission of direct injection diesel engine with ethanol-diesel blend

2016 ◽  
Vol 20 (suppl. 4) ◽  
pp. 937-946 ◽  
Author(s):  
Venkadesan Gnanamoorthi ◽  
Navin Marudhan ◽  
Devaradjane Gobalakichenin
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Direct Injection ◽  
Direct Injection Diesel Engine
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