Computational Modeling of Natural Gas Injection in a Large Bore Engine

2002 ◽  
Author(s):  
Gi-Heon Kim ◽  
Allan Kirkpatrick ◽  
Charles Mitchell
Keyword(s):  
High Pressure ◽  
Fluid Flow ◽  
Computational Modeling ◽  
Gas Flow ◽  
Gas Injection ◽  
Cylinder Wall ◽  
Poppet Valve ◽  
Injection Process ◽  
Pressure Injection ◽  
Planar Laser

The topic of this paper is the computational modeling and experimental visualization of gas injection in a large bore engine. The injection process is accomplished through the use of a mechanically or electrically controlled poppet valve. The objective of the paper is to more fully understand the significance of the poppet valve and the piston top in controlling the mixing of the injected fuel with the air in the cylinder. In this paper, the flow past the poppet valve into the engine cylinder is computed using computational fluid dynamics (CFD) for both a low (4 bar) and a high pressure (34 bar) injection process using unshrouded and shrouded valves. Flow visualization using planar laser induced fluorescence (PLIF) is used to visualize the actual fluid flow. The results indicate that for low pressures the gas flow around the poppet valve collapses downstream of the poppet. At high pressure, the gas flow does not collapse, but flows along the cylinder wall, producing poor mixing in the cylinder. To obtain satisfactory fluid flow at high pressure, the results indicated a shroud should be employed around the poppet valve to direct the gas into the center of the cylinder. Additional computations show that at top dead center, the flammable mixture and fuel mass fraction for the high-pressure injection are significantly greater than for the low-pressure injection.

Computational Modeling of Natural Gas Injection in a Large Bore Engine

2004 ◽  
Vol 126 (3) ◽  
pp. 656-664 ◽  
Author(s):  
Gi-Heon Kim ◽  
Allan Kirkpatrick ◽  
Charles Mitchell
Keyword(s):  
High Pressure ◽  
Computational Modeling ◽  
Gas Flow ◽  
High Pressures ◽  
Volume Fraction ◽  
Gas Injection ◽  
Cylinder Wall ◽  
Poppet Valve ◽  
Injection Process ◽  
Planar Laser

The topic of this paper is the computational modeling of gas injection through various poppet valve geometries in a large bore engine. The objective of the paper is to contribute to a better understanding of the significance of the poppet valve and the piston top in controlling the mixing of the injected fuel with the air in the cylinder. In this paper, the flow past the poppet valve into the engine cylinder is computed for both a low (4 bar) and a high pressure (35 bar) injection process using unshrouded and shrouded valves. Experiments using PLIF (planar laser induced fluorescence) are used to visualize the actual fluid flow for the valve geometries considered. The results indicate that for low injection pressures the gas flow around a typical poppet valve collapses to the axis of symmetry of the valve downstream of the poppet. At high pressure, the gas flow from this simple poppet valve does not collapse, but rather expands outward and flows along the cylinder wall. At high pressures, addition of a shroud around the poppet valve was effective in directing the supersonic flow toward the center of the cylinder. Additional computations with a moving piston show that at top dead center, the flammable volume fraction and turbulence intensity with high pressure shrouded injection are larger than for low pressure injection.

Planar Laser Induced Fluorescence Imaging of Gas Injection From Fuel Valves for Large Bore Natural Gas Engines

2001 ◽  
Author(s):  
Daniel B. Olsen ◽  
Dan B. Mastbergen ◽  
Bryan D. Willson
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Fuel Injection ◽  
Gas Injection ◽  
Laser Induced Fluorescence ◽  
Natural Gas Engines ◽  
Pressure Injection ◽  
Fuel Jet ◽  
Planar Laser ◽  
High Pressure Injection

Abstract Investigations of the fuel injection process for large bore natural gas engines are performed on an off-engine test fixture. Two types of fuel injectors are studied, a low pressure (0.39 MPa) and a high pressure (3.5 MPa) gas injection valve. Planar laser induced fluorescence is implemented to image fuel jet concentration. The fuel jet from each injector is imaged from the start of injection though their valve-open duration. Effects of injection pressure, piston interaction, and injection event repeatability are investigated. The results are related to previous engine studies of high pressure fuel injection and Schlieren photography of in-cylinder events on a Cooper-Bessemer GMV large bore natural gas engines. The images indicate that the low pressure valve achieves more effective mixing during jet penetration. The high pressure injection event shows relatively little mixing during jet penetration. However, the high pressure jet has much more energy when it impinges on the piston. It is evident that the important time for mixing using high pressure injection occurs after piston impingement.

Turbine-Compressor Train Uprated for 30% Increase in Gas Flow

1991 ◽  
Author(s):  
C. D. (Charlton) Breon ◽  
D. R. (Daniel) Veth
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Gas Flow ◽  
Gas Injection ◽  
Oil Field ◽  
General Electric ◽  
Prudhoe Bay

A turbine-compressor train consisting of a General Electric MS5001 Model R single-shaft gas turbine, a Philadelphia Gear speed-increasing gearbox, and a Dresser-Clark centrifugal compressor was uprated for 30% increased gas throughput. This train is one of thirteen units operated by ARCO Alaska, Inc. for high pressure natural gas injection service in Alaska’s Prudhoe Bay Oil Field. The uprate included an in-place conversion of the gas turbine from a Model R to a Model P configuration. This paper describes the engineering, planning, and implementation activities that led up to the successful uprate of this train with only a 24 day equipment outage.

Factors Influencing Foam Height in Gas Injection Process for Aluminum Foams

2015 ◽  
Vol 1104 ◽  
pp. 33-37
Author(s):  
Jian Yu Yuan ◽  
Yan Xiang Li ◽  
Xiang Chen ◽  
Yu Tong Zhou
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Foam Stability ◽  
Gas Injection ◽  
Foam Height ◽  
Gas Flow Rate ◽  
Aluminum Foams ◽  
Particle Content ◽  
Injection Process ◽  
Factors Influencing

The present study proposed a convenient method to characterize the stability of aluminum foams by utilizing the resulting foam height. The factors influencing foam height in gas injection process was investigated including the blowing gas (N2 and air), particle content (5vol.%-15vol.%), gas flow rate (0.03m3/h-0.3m3/h) and orifice size (0.3mm and 0.5mm). Factors that contribute to the foam stability including oxygen in the blowing gas and larger particle content in the melt was proved to be positively related to the foam height. Moreover, it was found that larger gas flow rate and smaller orifice size lead to larger foam height. The cell wall microstructure and thickness was also analyzed to better understand the foaming behavior. The present study offers favorable proof that the foam height in the gas injection process can be a good index for the foam stability.

Analytical and Computational Modeling of High Pressure Gas Injection

2001 ◽  
Author(s):  
Allan Kirkpatrick ◽  
Yuan Li ◽  
Charles Mitchell ◽  
Bryan Willson
Keyword(s):  
Computational Modeling ◽  
Method Of Characteristics ◽  
Pressure Ratio ◽  
Gas Injection ◽  
Injection Pressure ◽  
Rarefaction Waves ◽  
Axisymmetric Nozzle ◽  
Injection Process ◽  
Flow Features ◽  
Shock Location

Abstract The topic of this paper is the analytical and computational modeling of the gas injection process in a large bore natural gas fueled engine. At high injection pressures, the overall gas injection and mixing process includes compressible flow features such as rarefaction waves and shock formation. The injection geometries examined in the paper include both a two dimensional slot and an axisymmetric nozzle. The computations examine the effect of the injection pressure/back pressure ratio, with ratios ranging from 3 to 80. The computational modeling was validated by comparison with results obtained from a 2D analytical method of characteristics solution. The validation process evaluated factors such as pressure and Mach number profiles, jet boundary shape and shock location.

Simulation of Fast Gas Injection Expansion Phase Experiments

2010 ◽  
Author(s):  
Donella Pellini ◽  
Werner Maschek ◽  
Nicola Forgione ◽  
Francesco Poli ◽  
Francesco Oriolo
Keyword(s):  
High Pressure ◽  
Time Trend ◽  
Gas Injection ◽  
Liquid Pool ◽  
Pressure Effects ◽  
Expansion Phase ◽  
Rising Bubble ◽  
Experimental Campaign ◽  
Pressure Injection ◽  
Good Agreement

The injection of a high pressure gas into a stagnant liquid pool is the characteristic phenomenon during the expansion phase of a hypothetical core disruptive accident in liquid metal cooled fast reactors. In order to investigate lot of mechanism involved in this phase of the accident’s evolution, an experimental campaign called SGI was performed in 1994 in Forschungszentrum Karlsruhe, now KIT. This campaign consists of nine experiments which have been dedicated to assess the effects of different pressure injection, the nozzle’s size and the presence of inner confinement in the formation of the rising bubble. Three of these experiments, which were focused on the pressure effects, have now been simulated with SIMMER III code and with FLUENT 6.3 code, a commercial CFD code. Both codes, despite their different features, have showed a good agreement with the experimental results. In particular, time trend evolutions of pressures and bubble volumes have been well reproduced by simulation. Furthermore, both codes agree on the shape of the bubble, even though they have evidenced same discrepancies with the experimental shape.

Computational modeling of high pressure combustion mechanism in scram accelerator

2000 ◽  
Vol 10 (PR11) ◽  
pp. Pr11-131-Pr11-141 ◽  
Author(s):  
J.-Y. Choi ◽  
B.-J. Lee ◽  
I.-S. Jeung
Keyword(s):  
High Pressure ◽  
Computational Modeling ◽  
Combustion Mechanism
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