Inclined Piston Crown Surface for Exhaust-Directed Gas Flow
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Solution Overview
Problem
Existing pistons for internal combustion engines fail to optimize the displacement of aerodynamic gas movement towards the exhaust during the upward stroke, leading to potential aerodynamic recirculation zones and localized areas of low turbulent kinetic energy, which can cause hot spots and inefficient combustion.
Innovation Solution
The piston design includes recesses for intake and exhaust valves with a connecting surface featuring an inclined portion directed towards the exhaust valve recess, offset from the median axis, to optimize gas movement and prevent recirculation zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional piston designs with recesses for intake and exhaust valves are used, then the piston can accommodate valve operations, but aerodynamic recirculation zones form in the combustion chamber causing localized low turbulent kinetic energy and hot spots
Solution Approach 1:
The connecting surface between intake and exhaust valve recesses is given a specific inclination (5-15 degrees relative to the perpendicular of the piston axis) to create localized aerodynamic guidance. This local geometric modification directs the macroscopic gas movement toward the exhaust side, preventing recirculation zones in critical areas while maintaining valve operation functionality.
Solution Approach 2:
The connecting surface is designed with asymmetric inclination toward the exhaust valve recess rather than being symmetric or perpendicular to the piston axis. This asymmetric geometry creates a preferential flow path that guides the aerodynamic movement of gases, eliminating recirculation zones and hot spots while preserving the necessary valve access.
2Ease of manufacture
If the piston design is simplified to reduce complexity, then manufacturing becomes easier, but the ability to optimize aerodynamic gas movement and prevent recirculation zones is reduced
Solution Approach 1:
Rather than redesigning the entire piston geometry, the solution applies a localized inclination modification only to the connecting surface between valve recesses. This minimal geometric change can be integrated into existing piston manufacturing processes while specifically targeting the aerodynamic problem area without increasing overall manufacturing complexity.
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 enhances the direction of aerodynamic gas movement towards the exhaust, reducing high-temperature zones and improving combustion efficiency by minimizing recirculation areas.
Implementation Method 1
the macroscopic movement of the fuel mixture is a combination of swirl (rotational movement of gases in the cylinder around a vertical axis) and tumble (rotational movement of gases in the cylinder along a longitudinal axis)
Implementation Method 2
In order to ensure good efficiency and a good combustion speed, it is desirable to have a high level of turbulence, and more specifically a high level of turbulent kinetic energy, at the moment of ignition of the fuel mixture and during its combustion
Data Source
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AI summary
The present invention relates to a piston (1) for an internal combustion engine, comprising recesses for intake valves (2) and exhaust valves (3), and a surface (4) for connection between the recesses for the intake valves (2) and exhaust valves (3), said connecting surface (4) comprising a portion (5) inclined in the direction of the at least one recess for the exhaust valve (3).