A novel tracer-gas injection system for scrape-off layer impurity transport and screening experiments

This study aims at the parametric investigation of the gas injection system settings of a large marine two-stroke dual fuel engine by using a developed and customized CFD method in the ANSYS Fluent software. The investigated engine injection system parameters include the gas injection timing, the gas injection duration, the gas injector lateral angle, and the gas injector holes number. Based on the comparison of the predicted performance parameters for the closed-cycle processes, the results indicate that the gas injector lateral angle is the most significant parameter that affects the engine power as well as the NO and CO2 emissions. For satisfying the contradictory objectives of retaining the engine power and reducing the NO and CO2 emissions, appropriate design settings for the gas injection are recommended for the investigated engine operation in the gas mode at 75% load.

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Comparison of Pathogens Dispersion in an Aircraft Cabin Using Gas Injection Source Versus a Coughing Manikin

Volume 1: Fluid Applications and Systems; Fluid Measurement and Instrumentation ◽

10.1115/fedsm2020-20095 ◽

2020 ◽

Author(s):

Seif Mahmoud ◽

James S. Bennett ◽

Mohammad H. Hosni ◽

Byron Jones

Keyword(s):

Gas Injection ◽

Longitudinal Direction ◽

Injection Rate ◽

Sampling Location ◽

Tracer Gas ◽

Low Velocity ◽

Co2 Gas ◽

Gas Concentration ◽

Continuous Injection ◽

Injection Location

Abstract The dispersion characteristics of airborne pathogens were investigated in a Boeing 767 mockup cabin containing 11 rows with 7 seats per row, using two tracer gas source methods: continuous injection at low velocity and a coughing manikin. Both the injection source and the coughing manikin were located on the same seat in the sixth row. The injection source utilized CO2 gas at an injection rate of 5.0 liters per minute mixed with helium at a rate of 3.07 liters per minute to neutralize buoyancy. The manikin coughed approximately once every 75 seconds, with a volume of 4.2 liters of CO2 per cough. To ensure sufficient data were collected at each sampling location, each coughing manikin test was run for 6 coughs and each injection source test for 30 minutes of continuous injection. In both test methods, the tracer gas concentration was measured using CO2 gas analyzers at seated passenger breathing height of 1.2 m and radially up to 3.35 m away from the gas injection location, representing approximately four rows of a standard B767 aircraft. The collected data obtained from each tracer method was then normalized to provide a suitable comparison basis that is independent of tracer gas introduction flowrate. The results showed that both tracer source methods gave similar dispersion trends in diagonal and lateral directions away from the injection location. However, the tracer gas concentration was higher along the longitudinal direction in the coughing manikin tests due to the cough momentum. The results of this work will help researchers analyze different experimental and numerical approaches used to determine contaminant dispersion in various environments and will provide a better understanding of the associated transport phenomena.

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Study of CNG Fueled Two-Wheeled Vehicle with Electronically Controlled Gas Injection System

10.4271/2005-32-0034 ◽

2005 ◽

Author(s):

Takashi Tsutsumizaki ◽

Masahiro Kuroki

Keyword(s):

Gas Injection ◽

Injection System ◽

Wheeled Vehicle

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Effects of Ammonia Gas Mixed Into Intake Air on Combustion and Emissions Characteristics in Diesel Engine

ASME 2016 Internal Combustion Engine Fall Technical Conference ◽

10.1115/icef2016-9364 ◽

2016 ◽

Cited By ~ 2

Author(s):

Yoichi Niki ◽

Dong-Hoon Yoo ◽

Koichi Hirata ◽

Hidenori Sekiguchi

Keyword(s):

Diesel Engine ◽

Catalytic Reduction ◽

Gas Injection ◽

Experimental Results ◽

Injection System ◽

Emission Characteristics ◽

Diesel Injection ◽

Injection Quantity ◽

Carbon Dioxide Co2 ◽

Scr System

This paper reports on the experimental results of the combustion and emission characteristics of a conventional diesel engine mixed ammonia (NH3) gas into the intake air, and discusses its usability. In the experiments, NH3 gas was injected into the intake pipe of the diesel engine by a gas injector. The diesel engine has a natural aspiration single cylinder with 7.7 kW rated power at 1500 rpm and a diesel injection system to inject diesel fuel into the cylinder. As experimental results on the combustion characteristics, it was confirmed that the compression and maximum pressures in the cylinder decreased and the ignition timing delayed with increasing the NH3 gas injection quantity. On the emission characteristics in the exhaust gas, NH3, water (H2O) and nitrous oxide (N2O) increased and carbon dioxide (CO2) decreased proportionally to the NH3 gas injection quantity. In contract, the nitrogen oxide (NO) was nearly the same. Moreover, it was confirmed that NH3 can be reduced by reacting with NO in a selective catalytic reduction (SCR) system.

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