Bluff Body Combustion System for Soot Reduction
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Solution Overview
Problem
Internal combustion engines with direct fuel injection systems often produce unoxidized soot due to insufficient oxidant access, leading to soot buildup and undesirable emissions, as existing designs fail to effectively mitigate soot formation in these engines.
Innovation Solution
A combustion system featuring a bluff body within the combustion chamber that splits fuel jets into turbulent streams, facilitating mixing with oxidants, and includes orifices and a passageway to enhance oxidant entrainment and mixing, thereby reducing soot formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If direct fuel injection is used to improve combustion efficiency, then fuel-rich core formation occurs which leads to insufficient oxidant access and increased soot production
Solution Approach 1:
The fuel jet is segmented into multiple streams by the bluff body, breaking up the fuel-rich core into smaller zones that can mix more effectively with oxidant, thereby reducing soot formation while maintaining combustion efficiency
Solution Approach 2:
The bluff body creates localized turbulent mixing zones within the combustion chamber where fuel and oxidant are thoroughly mixed, ensuring that fuel-rich regions are converted to well-mixed regions that burn more cleanly
2Reliability
If unoxidized soot is allowed to accumulate in the combustion chamber, then detrimental effects such as lubricant sludging occur, but removing it requires additional emission control measures
Solution Approach 1:
The bluff body converts the harmful fuel-rich core into beneficial turbulent mixing that promotes complete combustion, transforming what would be a source of soot into a mechanism that prevents soot formation in the first place
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively oxidizes fuel-rich cores, reducing soot emissions and minimizing detrimental effects like lubricant sludging, while improving combustion efficiency and reducing particulate matter in engine emissions.
Implementation Method 1
The anterior portion has a contour that is adapted to split at least a portion of the dispensed fuel jet into at least two turbulent fuel streams and facilitate mixing of each fuel stream with an oxidant present in the combustion chamber
Implementation Method 2
The first orifice could be disposed in fluid communication with the second orifice via a passageway such that the first orifice can entrain an oxidant, for instance, air from a portion of the combustion chamber adjacent the first orifice and communicate the entrained oxidant to a portion of the combustion chamber adjacent the second orifice via the passageway
Implementation Method 3
The solution effectively oxidizes fuel-rich cores, reducing soot emissions and minimizing detrimental effects like lubricant sludging
Data Source
AI summary
A combustion system for an internal combustion engine includes a cylinder wall; a cylinder head disposed at an end of the cylinder wall, an internal surface of the cylinder wall and the cylinder head defining a combustion chamber; a fuel injector having a discharge nozzle disposed within the combustion chamber and configured to discharge a fuel jet along a fuel jet axis; and a bluff body disposed within the combustion chamber, the fuel jet axis intersecting an exterior surface of the bluff body. The exterior surface defines a first aperture and a second aperture therethrough, and an interior surface of the bluff body defines a first flow passage extending from the first aperture to the second aperture. The first aperture faces away from the fuel jet axis and the second aperture faces away from the fuel injector along the fuel jet axis.