Combustion Chamber Injector Tunnel Protrusion Grooves
Solution Overview
Problem
In internal combustion engines using gaseous fuels like hydrogen, existing combustion chambers face challenges in achieving homogeneous fuel and air mixture formation, leading to NOx emissions and unburned fuel due to uneven distribution, which is exacerbated by airflow impacts.
Innovation Solution
The combustion chamber design incorporates a protrusion and pair of grooves in the injector tunnel opening to redirect the fuel flow, preventing the Coanda effect and ensuring even distribution by guiding the fuel away from the chamber roof and towards the cylinder, enhancing penetration and homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fuel is injected directly into the cylinder without flow guidance structures, then the injection system is simple, but the fuel mixture distribution becomes uneven causing NOx emissions and unburned fuel
Solution Approach 1:
The injector tunnel opening is segmented into multiple functional zones: a central protrusion that redirects fuel flow away from the chamber roof, and lateral grooves that guide fuel to both sides of the cylinder. This segmentation creates controlled flow paths that ensure homogeneous fuel-air mixture distribution throughout the combustion chamber.
Solution Approach 2:
Different regions of the injector tunnel opening are given different geometric properties to achieve specific flow control functions. The protrusion creates a high-flow region that redirects fuel centrally, while the grooves create lateral flow regions. Each local structure is optimized for its specific function to collectively achieve uniform fuel distribution.
2Manufacturing precision
If the injector tunnel opening directs fuel toward the chamber roof, then the injection path is simple, but the Coanda effect causes fuel to adhere to the roof surface reducing mixture homogeneity
Solution Approach 1:
The protrusion is positioned to preemptively intercept and redirect fuel flow before it can contact the chamber roof surface. By creating a flow separation at the protrusion edges, the design prevents the Coanda effect from initiating, ensuring fuel is distributed laterally into the cylinder rather than adhering to the roof.
Solution Approach 2:
Instead of allowing fuel to naturally follow the chamber roof surface (Coanda effect), the protrusion inverts the flow direction by creating a physical barrier that forces fuel to redirect away from the roof and toward the cylinder center and sides through the grooves.
3Manufacturing precision
If gaseous fuel and air are highly impacted by airflows, then natural mixing occurs, but uneven mixture formation leads to NOx emissions and unburned fuel
Solution Approach 1:
The injector tunnel geometry with protrusion and grooves performs preliminary fuel distribution work before combustion. By pre-positioning fuel in specific flow paths that ensure lateral and central distribution, the system prepares a homogeneous fuel-air mixture in advance, preventing localized rich or lean zones that would cause NOx or unburned fuel issues.
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
This design significantly improves the distribution of gaseous fuel throughout the combustion chamber, reducing NOx emissions and unburned fuel, leading to more efficient combustion and improved engine performance.
Implementation Method 1
preventing the Coanda effect and ensuring even distribution by guiding the fuel away from the chamber roof
Implementation Method 2
an injector tunnel opening disposed on an inner surface of the chamber roof being configured to guide the fuel injected in an injecting direction toward the cylinder
Implementation Method 3
a pair of grooves arranged on both sides of the protrusion to guide the fuel separated by the protrusion to both sides next to the protrusion acting as a side distribution effect
Implementation Method 4
a spark plug mounted on the chamber roof and configured to periodically ignite a mixture of the fuel and the air filled in the cylinder
Implementation Method 5
carrying out an engine cycle including a combustion due to a chemical reaction of fuel and air
Data Source
AI summary
An embodiment combustion chamber for an internal combustion engine includes a chamber body including a cylinder configured to receive fuel and air for carrying out an engine cycle including a combustion reaction of the fuel and a chamber roof including an injector tunnel opening disposed on an inner surface of the chamber roof, the injector tunnel opening being configured to guide the fuel injected in an injecting direction toward the cylinder, and the injector tunnel opening including a protrusion disposed on a path of the fuel along the injecting direction, the protrusion being configured to re-direct the path of the fuel along a re-directed path away from the inner surface of the chamber roof and a pair of grooves arranged on sides of the protrusion, respectively, the pair of grooves being configured to guide the fuel separated by the protrusion to the sides of the protrusion.