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Showing 1 to 20 of 24 for “"HCCI engine"”.
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Miniature HCCI Engine Compressor
… robotics. A prototype miniature free-piston engine compressor runs for up to 30 s. New pistons and cylinder liners with coatings did not improve reliability when implemented in the engine. The engine stalled because pressure could not be held in the cylinder due to blow-by leakage caused by …
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Closed-Loop Control of HCCI Engine Dynamics
… of Homogeneous Charge Compression Ignition (HCCI) engine dynamics. HCCI offers a potential to combine high efficiency with very low emissions. In order to fulfill the potential benefits, closed-loop control is needed. The thesis discusses sensors, feedback signals and actuators for …
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25cc HCCI engine fueled with Diethyl Ether
This research forms part of an ongoing HCCI study at the SASOL Advanced Fuels Laboratory to investigate and understand engine configuration and fuel chemistry effects on combustion in HCCI engines. This project continues from a previous project where a small Progress Aero Works (PAW) 6.5cc high …
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Examination of the high load limit of an HCCI engine
… of homogenous charge compression ignition (HCCI) to gasoline engines is constrained by many factors. This work examines constrains imposed by nitric oxide (NOx) emission and by the need to maintain a minimum catalyst temperature on HCCI operation. Then the nature of the approach to high load …
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Design of a viable homogeneous-charge compression-ignition (HCCI) engine : a computational study with detailed chemical kinetics
The homogeneous-charge compression-ignition (HCCI) engine is a novel engine technology with the potential to substantially lower emissions from automotive sources. HCCI engines use lean-premixed combustion to achieve good fuel economy and low emissions of nitrogen-oxides and particulate matter. …
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Closed-Loop Combustion Control of a Multi Cylinder HCCI Engine using Variable Compression Ratio and Fast Thermal Management
The current Spark Ignited (SI) engine equipped with three-way catalyst offers low emissions, but has low efficiency at part load, which results in unnecessarily high CO2 emissions. The Compression Ignited (CI) engines have higher efficiency and hence lower CO2 emissions, but suffer from higher …
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Extension of the high load limit in the Homogeneous Charge Compression Ignition engine
The Homogeneous Charge Compression Ignition (HCCI) engine offers diesel-like efficiency with very low soot and NOx emissions. In a HCCI engine, a premixed charge of air, fuel and burned gas is compressed to achieve autoigntion. Combustion occurs throughout the chamber volume resulting in short …
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Synthesis gas use in internal combustion engines.
… and homogeneous charge compression ignition engine operating on various blends of synthesis gas. To fully investigate the three ICE operating regimes, experimental investigations were carried out to focus on: 1.) A CI engine operating on ethanol and hydrogen fuel 2.) A CI engine operating on …
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Combustion Kinetics of Advanced Biofuels
… kinetics of the oxidation of DIPK in advanced engines such as, the homogeneous charge compression ignition (HCCI) engine is warranted. This dissertation concentrates on the combustion kinetics of DIPK over a wide range of temperature and pressure with a focus on HCCI engine application. An …
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Fuel effects in homogeneous charge compression ignition (HCCI) engines
Homogenous-charge, compression-ignition (HCCI) combustion is a new method of burning fuel in internal combustion (IC) engines. In an HCCI engine, the fuel and air are premixed prior to combustion, like in a spark-ignition (SI) engine. However, rather than using a spark to initiate combustion, the …
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Two contrasting approaches to auto-ignition modelling for HCCI engines
… in Homogeneous Charge Compression Ignition (HCCI) engines. The first (empirical) auto-ignition model was adapted from its previously published form, for HCCI engine model implementation. This model was then combined with an explicit, single zone, thermodynamic engine model in order to …
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Effect of ambient conditions and fuel properties on homogeneous charge compression ignition engine operation
… of Homogeneous Charge Compression Ignition (HCCI) combustion must demonstrate robust responses to variations in environmental conditions. This work examines the impact of ambient conditions and fuel changes on HCCI engine operation, and evaluates cam phasing as a mechanism to compensate for …
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A theoretical assessment of fuel combustion attributes to enhance the operational envelope of HCCI engines
Homogeneous Charge Compression Ignition (HCCI) is an alternative internal combustion (IC) engine that can provide high efficiencies while producing ultra-low nitrous oxides (NOx) and particulate matter (PM) emissions compared to existing compression ignition (CI) and spark ignition (SI) engines. …
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Developing fundamentally based models for autoignition
… of the homogenous charge compression ignition (HCCI) engine, highly promising with its low Nox and particulate emissions and high efficiency. However it is difficult to control HCCI autoignition. In general accurate prediction of the autoignition behavior of fuel/air mixtures has been difficult, …
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Managing transient behaviors of a dual mode spark ignition-- controlled auto ignition engine with a variable valve timing system
Gasoline Homogeneous Charge Compression Ignition (HCCI) engine has the potential of providing better fuel economy and emissions characteristics than current spark ignition engines. One implementation of this technology employs a Variable Valve Timing (VVT) system and is also often referred to as …
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Modelling and diagnostic study of flow in an optical engine with negative valve overlapping for homogeneous charge compression ignition
The three-dimensional bulk gas motion in an engine cylinder with different flow scales generates a varied range of shear stresses and deformations in the fluid, which leads to the gas turbulence. These flow irregularities combined with periodic engine operation induce gas fluctuations over time and …
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Combustion diagnostics in Homogeneous Charge Compression Ignition optical and thermal single cylinder engines
… of a Homogeneous Charge Compression Ignition (HCCI) engine with a negative valve overlap (NVO) strategy. Conventional (pressure-transducer based) measurements and passive optical research have contributed to understanding of the chemical-physical sites of HCCI autoignition and combustion. This …
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