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Xu Boyan
Department of Mechanical and
Electronic Engineering,
Shandong Institute of Architecture
and Engineering,
Jinan 250014, China
Liang Fuyou
Faculty of Engineering,
Chiba University,
Chiba 263-8522, Japan
Cai Shaoli
School of Mechanical Engineering,
Jinan University,
Jinan 250022, China |
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NUMERICAL
ANALYSIS AND VISUALI-
ZATION OF NATURAL GAS JET WITH
MULTI-POINT INJECTION SYSTEM*
Abstract:
Aiming at the change in intake air flow caused by the injection of natural gas in intake manifold if one simply replaces the gasoline injector with natural gas injector with the installing position of injector in intake manifold unchanged, and also the reflection of gas toward intake manifold inlet resulted from the impingement between the injected large volumetric natural gas jet and intake valve, an impulsively started natural gas jet injected from a gas injector is characterized as a three-dimensional unsteady compressible viscous turbulent flow, based on which its transient development process is numerically analyzed using general-purpose CFD codes. The predicted velocity vector maps show a vortex, which indicates the occurrence of an unsteady state jet region, is formed downstream of the jet. A schlieren apparatus is utilized to get several groups of visible schlieren photographs of natural gas jets. In the experiment, photographs of natural gas jets taken by a CCD camera are laid in a portrait processor where the shapes, tip penetration distance and injection angles of the gas jets are investigated. Comparisons between predicted results and measurements indicate an excellent agreement between simulations and experimental results.
Key words:
Natural gas injector Jet Numerical analysis Schlieren photograph |