Hydrogen Injector Outlet Contour for Stable Fuel-Air Mixing
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Solution Overview
Problem
Current hydrogen combustion engines face challenges in achieving homogeneous combustion and efficient fuel-air mixing due to the low molecular weight and low density of hydrogen, requiring large flow cross-sections and actuator strokes, which affect combustion stability and efficiency.
Innovation Solution
An injection line with a specific inner contour featuring convex and concave sections, ramps, and additional openings to create turbulence and ensure thorough mixing of fuel and air, allowing for supersonic flow transitions to enhance combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If hydrogen is injected using conventional injection lines, then the injection system is simple, but fuel-air mixing is insufficient and combustion is not homogeneous
Solution Approach 1:
The injection line employs curved inner contours with convex and concave sections instead of straight lines, creating turbulence and enhancing fuel-air mixing. The curved geometry generates rotational flow patterns that improve combustion homogeneity while maintaining a relatively simple injection line structure.
Solution Approach 2:
The inner contour of the injection line is segmented into multiple convex and concave sections along the flow direction. This segmentation creates localized turbulence zones that progressively mix fuel and air, achieving homogeneous combustion through distributed mixing rather than a single complex mixing chamber.
2Stability of the object's composition
If the injection line has a simple inner contour, then manufacturing is easy, but fuel-air mixing is insufficient
Solution Approach 1:
The curved inner contour with convex and concave sections can be manufactured using standard casting or machining processes. The curvature profiles are designed to be manufacturable with conventional tolerances, avoiding overly complex geometries while still achieving the desired turbulence and mixing effects.
3Quantity of substance
If hydrogen injection uses large flow cross-sections, then sufficient volume flow is achieved, but actuator strokes become larger affecting efficiency
Solution Approach 1:
The injection line changes the flow parameters through its curved geometry, transforming the flow from laminar to turbulent and increasing mixing efficiency. This allows for reduced cross-sectional areas while maintaining sufficient volume flow rates, as the turbulence enhances mass transfer and combustion efficiency.
4Stability of the object's composition
If conventional injection lines are used, then the system is simple, but combustion stability is poor
Solution Approach 1:
The segmented inner contour with alternating convex and concave sections creates multiple small-scale turbulence zones along the flow path. This segmentation approach improves combustion stability through distributed mixing without requiring a single large complex mixing chamber, maintaining relatively simple injection line design.
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 injection line facilitates improved fuel-air mixing and combustion stability by generating turbulence and decoupling mass flow from engine backpressure, resulting in efficient and precise combustion processes.
Implementation Method 1
The specific internal contour of the injection line, in particular the design of the outlet cross-section and flow-guiding structures, remains undefined... The injection line has at least one outlet opening through which the fuel to be injected flows and is characterized in that an inner contour of an outlet cross-section of the at least one outlet opening has at least one convex and at least one concave section
Implementation Method 2
allowing for supersonic flow transitions to enhance combustion efficiency
Data Source
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AI summary
The invention relates to an injection conduit for an injector for fuel injection, particularly gaseous fuel and preferably hydrogen, which comprises at least one outlet opening through which the injectable fuel can flow, characterised in that an inner contour of an outlet cross-section of the at least one outlet opening comprises both at least one convex and at least one concave section.