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Records with Keyword: Diesel
Diesel-Minimal Combustion Control of a Natural Gas-Diesel Engine
Florian Zurbriggen, Richard Hutter, Christopher Onder
October 23, 2018 (v1)
Keywords: closed-loop control, combustion control, Diesel, dual fuel, engine control, extremum seeking, internal combustion engine, Natural Gas, Optimization
This paper investigates the combustion phasing control of natural gas-diesel engines. In this study, the combustion phasing is influenced by manipulating the start and the duration of the diesel injection. Instead of using both degrees of freedom to control the center of combustion only, we propose a method that simultaneously controls the combustion phasing and minimizes the amount of diesel used. Minimizing the amount of diesel while keeping the center of combustion at a constant value is formulated as an optimization problem with an equality constraint. A combination of feedback control and extremum seeking is used to solve this optimization problem online. The necessity to separate the different time scales is discussed and a structure is proposed that facilitates this separation for this specific example. The proposed method is validated by experiments on a test bench.
Macroscopic and Microscopic Spray Characteristics of Diesel and Gasoline in a Constant Volume Chamber
Moo-Yeon Lee, Gee-Soo Lee, Chan-Jung Kim, Jae-Hyeong Seo, Ki-Hyun Kim
September 21, 2018 (v1)
Keywords: Diesel, Gasoline, liquid penetration, microscopic spray visualization, vapor penetration
The aim of this study is to investigate the spray characteristics of diesel and gasoline under various ambient conditions. Ambient conditions were simulated, ranging from atmospheric conditions to high pressure and temperature conditions such as those inside a combustion chamber of an internal combustion engine. Spray tip penetration and spray cross-sectional area were calculated in liquid and vapor spray development. In addition, initial spray development and end of injection near nozzle were visualized microscopically, to study spray atomization characteristics. Three injection pressures of 50 MPa, 100 MPa, and 150 MPa were tested. The ambient temperature was varied from 300 K to 950 K, and the ambient density was maintained between 1 kg/m³ and 20 kg/m³. Gasoline and diesel exhibited similar liquid penetration and spray cross-sectional area at every ambient density condition under non-evaporation. As the ambient temperature increased, liquid penetration length and spray area of both... [more]
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