Numerical analysis and visualization of natural gas jet with multi-point injection system

2005 ◽  
Vol 18 (04) ◽  
pp. 550 ◽  
Author(s):  
Boyan Xu
Keyword(s):  
Numerical Analysis ◽  
Natural Gas ◽  
Injection System ◽  
Gas Jet ◽  
Point Injection

Analysis of the Air-Fuel Mixture Control in Natural Gas Fuelled Turbocharged Engines

2008 ◽  
Author(s):  
Francisco Payri ◽  
Jose Galindo ◽  
Jose Manuel Luja´n ◽  
He´ctor Climent
Keyword(s):  
Natural Gas ◽  
Public Transportation ◽  
Dynamic Properties ◽  
Fluid Dynamic ◽  
Fuel Mixture ◽  
Injection System ◽  
Intake Manifold ◽  
Injection Timing ◽  
Gas Dispersion ◽  
Point Injection

The use of natural gas in medium and heavy duty engines for public transportation is a promising way for reducing exhaust emissions. Computer simulations, coupled with engine tests, have arisen as a valuable methodology to study the gas exchange processes inside intake and exhaust manifolds. A wave action model is set up in order to simulate a natural gas fuelled turbocharged engine. Once the modeling results show good agreement when comparing with measured data at different running conditions in terms of fluid dynamic properties, the model is used to study the air-fuel mixture process in the intake manifold and optimize the injection system behavior. Comparisons of modeled air-fuel composition in the cylinders are performed with both single and multi-point injection strategies. These cylinder to cylinder air-fuel mixture dispersion problems are analyzed at both steady and transient engine running conditions. Steady operation is performed correctly when using single-point injection since the gas mixer upstream the throttle valve enhances the mixing process. However, significant gas dispersion among cylinders appears during an engine load transient. With multi-point injection the critical parameter is the injection timing, since it is usually larger than the intake stroke period and, if it is not conveniently arranged, significant natural gas dispersion among cylinders may appear at both steady and transient running conditions.

Optimum design of vaporizer fin with Liquefied Natural Gas by numerical analysis

2006 ◽  
Vol 20 (4) ◽  
pp. 545-553 ◽  
Author(s):  
Hyo-Min Jeong ◽  
Han-Shik Chung ◽  
Sang-Chul Lee ◽  
Tae-Woo Kong ◽  
Chung-Seub Yi
Keyword(s):  
Numerical Analysis ◽  
Natural Gas ◽  
Optimum Design ◽  
Liquefied Natural Gas

A Numerical Investigation on Mixing Characteristics of Natural Gas Jets With High-Pressure Injection

2021 ◽  
Author(s):  
Long Liu ◽  
Tianyang Dai ◽  
Qian Xiong ◽  
Yuehua Qian ◽  
Bo Liu
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Air Entrainment ◽  
Gas Jet ◽  
Swirl Ratio ◽  
Marine Engine ◽  
Low Speed ◽  
Pressure Injection ◽  
Mixing Characteristics ◽  
High Pressure Injection

Abstract With increasingly stringent emissions limitation of greenhouse gas and atmospheric pollutants for ship, the direct injection of natural gas on the cylinder head with high-pressure injection is an effective method to make a high power output and decrease harmful gas emissions in marine natural gas dual fuel engines. However, the effects on mixing characteristics of high-pressure natural gas underexpanded jet have not been fully understood. Especially, the injection pressure is up to 30 MPa with large injection quantity and critical surrounding gas conditions for the low-speed two-stroke marine engine. Therefore, this research is focused on the flow and mixing process of the natural gas jet with high-pressure injection under the in-cylinder conditions of low-speed two-stroke marine engine. The gas jet penetration, the distribution of velocity and density, the equivalence ratio and air entrainment have been analyzed under different nozzle hole diameters by numerical simulation. The effects of surrounding gas conditions including pressure, temperature and swirl ratio on air entrainment and equivalence ratio distribution were studied in detail. From the numerical simulation, it is found that the mixing characteristics of natural gas jet can be improved under in-cylinder conditions of higher ambient temperature and swirl ratio, which is relevant to the low-speed two-stroke marine engine.

Numerical Analysis of Carbon Black Production from Sub‐Quality Natural Gas

2008 ◽  
Author(s):  
M. Moghiman ◽  
M. Javadi ◽  
M. H. Ghodsirad ◽  
N. Hosseini ◽  
M. Soleimani
Keyword(s):  
Numerical Analysis ◽  
Natural Gas ◽  
Carbon Black ◽  
Carbon Black Production

A quasi-one-dimensional model for an outwardly opening poppet-type direct gas injector for internal combustion engines

2019 ◽  
Vol 21 (8) ◽  
pp. 1493-1519
Author(s):  
Abhishek Y Deshmukh ◽  
Carsten Giefer ◽  
Dominik Goeb ◽  
Maziar Khosravi ◽  
David van Bebber ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Flow Model ◽  
Direct Injection ◽  
Source Model ◽  
Gas Jet ◽  
Nozzle Flow ◽  
Combustion Engines ◽  
Compressed Natural Gas ◽  
One Dimensional

Direct injection of compressed natural gas in internal combustion engines is a promising technology to achieve high indicated thermal efficiency and, at the same time, reduce harmful exhaust gas emissions using relatively low-cost fuel. However, the design and analysis of direct injection–compressed natural gas systems are challenging due to small injector geometries and high-speed gas flows including shocks and discontinuities. The injector design typically involves either a multi-hole configuration with inwardly opening needle or an outwardly opening poppet-type valve with small geometries, which make accessing the near-nozzle-flow field difficult in experiments. Therefore, predictive simulations can be helpful in the design and development processes. Simulations of the gas injection process are, however, computationally very expensive, as gas passages of the order of micrometers combined with a high Mach number compressible gas flow result in very small simulation time steps of the order of nanoseconds, increasing the overall computational wall time. With substantial differences between in-nozzle and in-cylinder length and velocity scales, simultaneous simulation of both regions becomes computationally expensive. Therefore, in this work, a quasi-one-dimensional nozzle-flow model for an outwardly opening poppet-type injector is developed. The model is validated by comparison with high-fidelity large-eddy simulation results for different nozzle pressure ratios. The quasi-one-dimensional nozzle-flow model is dynamically coupled to a three-dimensional flow solver through source terms in the governing equations, named as dynamically coupled source model. The dynamically coupled source model is then applied to a temporal gas jet evolution case and a cold flow engine case. The results show that the dynamically coupled source model can reasonably predict the gas jet behavior in both cases. All simulations using the new model led to reductions of computational wall time by a factor of 5 or higher.

scholarly journals Research on Fuel Efficiency and Emissions of Converted Diesel Engine with Conventional Fuel Injection System for Operation on Natural Gas

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2413 ◽  
Author(s):  
Lebedevas ◽  
Pukalskas ◽  
Daukšys ◽  
Rimkus ◽  
Melaika ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Natural Gas ◽  
Fuel Injection ◽  
Injection System ◽  
Dual Fuel ◽  
Injection Timing ◽  
Fuel Injection System ◽  
Significant Deterioration ◽  
Engine Operation ◽  
Conventional Fuel

This paper presents a study on the energy efficiency and emissions of a converted high-revolution bore 79.5 mm/stroke 95 mm engine with a conventional fuel injection system for operation with dual fuel feed: diesel (D) and natural gas (NG). The part of NG energy increase in the dual fuel is related to a significant deterioration in energy efficiency (ηi), particularly when engine operation is in low load modes and was determined to be below 40% of maximum continuous rating. The effectiveness of the D injection timing optimisation was established in high engine load modes within the range of a co-combustion ratio of NG ≤ 0.4: with an increase in ηi, compared to D, the emissions of NOx+ HC decreased by 15% to 25%, while those of CO2 decreased by 8% to 16%; the six-fold CO emission increase, up to 6 g/kWh, was unregulated. By referencing the indicated process characteristics of the established NG phase elongation in the expansion stroke, the combustion time increase as well as the associated decrease in the cylinder excess air ratio (α) are possible reasons for the increase in the incomplete combustion product emission.

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