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.

Transient Behaviour of Glow Plugs in Direct Injection Natural Gas Engines

2011 ◽  
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 KIVA-3V 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.

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.

Soot and combustion models for direct-injection natural gas engines

2020 ◽  
pp. 146808742097801
Author(s):  
Kang Pan ◽  
James Wallace
Keyword(s):  
Kinetic Model ◽  
Natural Gas ◽  
Soot Formation ◽  
Direct Injection ◽  
Emission Characteristics ◽  
Gas Engine ◽  
Glow Plug ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Soot Model

This paper summarizes the validation of a modified multi-step phenomenological soot model and an enhanced combustion model used for direct-injection natural gas engines. In this study, a modified phenomenological soot model including the key steps for soot formation, such as particle inception and surface growth, was developed in KIVA-3V to replace the empirical model for use in a glow plug assisted natural gas direct-injection engine. The soot model was integrated with a CANTERA based kinetic model, which employs a recently developed low temperature natural gas mechanism to predict the reactions of some important gaseous species involved in the soot formation, such as acetylene and hydroxyl. The simulated in-cylinder flame propagation process induced by a glow plug was compared to the experimental optical images obtained in an engine-like environment. In addition, both the kinetic model and modified soot model were compared with the experimental emission data to validate their reliability for predicting natural gas engine emission characteristics. The engine combustion efficiencies obtained in simulations and experiments were compared as well. The matched results suggest that the computational models can well predict the natural gas combustion and emission characteristics, and will be suitable for investigating the direct-injection natural gas engine technologies.

K-2238 A Cold Start Procedure of Premixed-Compression-Ignition Natural-Gas Engines using a Hot Glow Plug

2001 ◽  
Vol V.01.1 (0) ◽  
pp. 311-312
Author(s):  
Yukihisa YAMAYA ◽  
Takaaki TAKEMOTO ◽  
Masahiro FURUTANI ◽  
Yasuhiko OHTA
Keyword(s):  
Natural Gas ◽  
Cold Start ◽  
Compression Ignition ◽  
Glow Plug ◽  
Natural Gas Engines

Thermal Dispersion in Metal Foams

2011 ◽  
Author(s):  
Teresa B. Hoberg ◽  
Kenshiro Muramatsu ◽  
Erica M. Cherry ◽  
John K. Eaton
Keyword(s):  
Heat Transfer ◽  
Molecular Diffusion ◽  
Metal Foam ◽  
Heated Surface ◽  
High Surface ◽  
Metal Foams ◽  
Thermal Engineering ◽  
Transfer Model ◽  
Thermal Dispersion ◽  
Transverse Mixing

Open-cell metal foams are of interest for a variety of thermal engineering applications because of their high surface-to-volume ratio and high convective heat transfer coefficients relative to conventional fins. The tortuous flow path through the foam promotes rapid transverse mixing, a fact that is important in heat exchanger applications. Transverse mixing acts to spread heat away from a heated surface, bringing cooler fluid to the foam elements that are in direct contact with the surface. Heat is also spread by conduction in the foam ligaments. The present work addresses fully-coupled thermal dispersion in a metal foam. Dispersion of the thermal wake of a line source was measured. A conjugate heat transfer model was developed which showed good agreement with the data. The validated model was used to examine the complementary effects of the mechanical dispersion, molecular diffusion in the gas, and conduction in the solid.

Railplug Design Optimization to Improve Large-Bore Natural Gas Engine Performance

2005 ◽  
Author(s):  
Hongxun Gao ◽  
Matt J. Hall ◽  
Ofodike A. Ezekoye ◽  
Ron D. Matthews
Keyword(s):  
Natural Gas ◽  
High Energy ◽  
Parameter Study ◽  
Transfer Model ◽  
High Speed Photography ◽  
Discharge Process ◽  
Ignition System ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine

It is a very challenging problem to reliably ignite extremely lean mixtures, especially for the low speed, high load conditions of stationary large-bore natural gas engines. If these engines are to be used for the distributed power generation market, it will require operation with higher boost pressures and even leaner mixtures. Both place greater demands on the ignition system. The railplug is a very promising ignition system for lean burn natural gas engines with its high-energy deposition and high velocity plasma jet. High-speed photography was used to study the discharge process. A heat transfer model is proposed to aid the railplug design. A parameter study was performed both in a constant volume bomb and in an operating natural gas engine to improve and optimize the railplug designs. The engine test results show that the newly designed railplugs can ensure the ignition of very lean natural gas mixtures and extend the lean stability limit significantly. The new railplug designs also improve durability.

scholarly journals Influence of spray-glow plug configuration on cold start combustion for high-speed direct injection diesel engines

Energy ◽  
2011 ◽  
Vol 36 (9) ◽  
pp. 5486-5496 ◽  
Author(s):  
J.V. Pastor ◽  
V. Bermúdez ◽  
J.M. García-Oliver ◽  
J.G. Ramírez-Hernández
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Direct Injection ◽  
Cold Start ◽  
Glow Plug

Kinetic Study of the Ignition Process of Methane/n-Heptane Fuel Blends under High-Pressure Direct-Injection Natural Gas Engine Conditions

2020 ◽  
Vol 34 (11) ◽  
pp. 14796-14813
Author(s):  
Jingrui Li ◽  
Xinlei Liu ◽  
Haifeng Liu ◽  
Ying Ye ◽  
Hu Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Kinetic Study ◽  
Direct Injection ◽  
Ignition Process ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Fuel Blends

Piston-Liner Thermal Resistance Model for Diesel Engine Simulation: Part 1: Formulation and Tuning

1991 ◽  
Vol 205 (5) ◽  
pp. 343-352 ◽  
Author(s):  
Y Rasihhan ◽  
F J Wallace
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Thermal Resistance ◽  
Direct Injection ◽  
Transfer Model ◽  
Conductive Heat ◽  
Axially Symmetric ◽  
Engine Simulation ◽  
Axial Movement ◽  
Resistance Model

A simple, effective and computationally economical piston-liner thermal resistance model for diesel engine simulation is described. In the model, the detailed shape of the piston and its axial movement and interaction with liner nodes are all taken into account. An imaginary node within the piston provides the necessary temperature difference between the piston and the liner nodes for conductive heat transfer, which is expected to reverse its direction with liner insulation. In the liner, an axially symmetric two-dimensional heat-transfer model is used. Later the piston-liner model is tuned for the experimental single cylinder, direct injection, Petter PH 1W engine used at Bath University, against the experimental piston temperature and liner temperature distribution.

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