Intake Port Curvature and Injection Axis for Engine Emissions
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Solution Overview
Problem
In port-injection internal combustion engines, fuel injected from upstream fuel injection valves can adhere to partition walls and inner walls of intake ports, leading to incomplete combustion and increased hydrocarbon emissions, despite the use of multiple fuel injection valves to mitigate this issue.
Innovation Solution
The engine design includes multiple intake ports with curved inner surfaces and strategically positioned fuel injection valves, where the injection axis intersects with the intake valve on the upstream side of the central axis, directing the fuel mist towards the combustion chamber and reducing adhesion to the inner wall surfaces by aligning the resultant vector of fuel and air flow towards the center.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If fuel injection valves are provided to each intake port, then fuel adhesion to partition wall is reduced, but fuel adhesion to inner wall of intake port still occurs causing increased hydrocarbon emissions
Solution Approach 1:
The invention modifies the local geometry of the intake port by providing a curved portion with a specific radius of curvature (R1) that is larger than the radius of curvature (R2) of the fuel spray trajectory. This local geometric modification changes the flow characteristics in the curved portion, preventing fuel droplets from adhering to the inner wall while maintaining effective fuel delivery to the combustion chamber.
Solution Approach 2:
The invention introduces a curved portion in the intake port with a controlled radius of curvature. This curvature is designed to match and exceed the radius of curvature of the fuel spray trajectory, allowing the fuel mist to follow a smoother path through the intake port without impinging on the walls, thereby reducing hydrocarbon emissions from unburnt fuel.
2Speed
If intake port is curved to direct air flow toward central axis, then air flow direction is improved, but fuel adhesion to curved portion inner wall surface increases
Solution Approach 1:
The invention changes the geometric parameter of the intake port by specifying a radius of curvature (R1) that is larger than the radius of curvature (R2) of the fuel spray. This parameter modification ensures that the curved portion is gentle enough to allow fuel mist to pass through without impinging on the walls, while still achieving the desired air flow direction toward the central axis of the combustion chamber.
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 configuration minimizes fuel adhesion to the intake port walls, enhancing fuel atomization and reducing unburnt hydrocarbon emissions, thereby improving fuel efficiency and exhaust gas quality.
Implementation Method 1
a fuel injection valve provided to a corresponding one of the plurality of intake ports to inject and thereby to supply fuel into the combustion chamber along the intake air through the curved portion and the opening
Implementation Method 2
The curved portion of each intake port includes a concavely curved inner peripheral wall surface, which is located on a downstream side of the central axis of the corresponding intake valve
Data Source
AI summary
A cylinder of an internal combustion engine is communicated with intake ports. Each of intake valves and each of fuel injection valves are provided to a corresponding one of the intake ports to inject fuel into a combustion chamber through a curved portion and an opening of the corresponding intake port. An injection axis of each fuel injection valve intersects with a surface of the corresponding intake valve placed in a close position at an intersecting point that is located on an upstream side of a central axis of the corresponding intake valve.