Piston Bowl Lip Chamfer Radius for Combustion Cylinder
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing combustion cylinder designs face challenges in scaling down engine size while maintaining high efficiency and low emissions, particularly in fuel injection behavior and swirl ratio, which affects fuel and air mixing and combustion characteristics.
Innovation Solution
The design of a spray guided piston bowl with a specific lip geometry and fuel injector configuration, optimized for smaller combustion cylinders, promotes efficient fuel distribution and mixing, reducing soot and NOx emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If engine size is reduced to improve fuel efficiency and meet regulatory requirements, then productivity and emissions performance improve, but fuel injection behavior and swirl ratio become difficult to maintain at optimal levels
Solution Approach 1:
The piston bowl geometry is specifically optimized with a deep, narrow configuration and particular surface curvature characteristics to create localized flow patterns that enhance swirl ratio and fuel-air mixing. This local geometric optimization compensates for the overall reduction in engine size, maintaining effective combustion characteristics in the smaller combustion chamber.
Solution Approach 2:
The invention modifies key geometric parameters of the piston bowl including depth-to-diameter ratio, rim thickness, and surface curvature radii to alter the flow dynamics within the combustion chamber. These parameter changes are specifically tuned to maintain optimal swirl ratio and fuel injection behavior in smaller engines, addressing the scalability issue.
2Productivity
If swirl ratio is increased to promote efficient fuel-air mixing and limit combustion gas penetration, then combustion efficiency improves, but the complexity of maintaining optimal swirl ratio across different engine sizes increases
Solution Approach 1:
The piston bowl incorporates specifically designed curved surfaces with optimized radius of curvature values. The spherical and toroidal surface geometries create predictable flow patterns that enhance swirl generation. This curvature-based design provides passive swirl control that maintains efficiency without adding complex active control mechanisms.
3Object-generated harmful factors
If piston bowl geometry is optimized for spray guided combustion in smaller cylinders, then emissions of soot and NOx reduce, but the design becomes more specialized and less adaptable to different engine configurations
Solution Approach 1:
The piston bowl geometry is divided into distinct functional zones including a central deep region for fuel injection and vaporization, intermediate curved surfaces for swirl generation, and outer rim structures for flame propagation. This segmentation allows each zone to be optimized for its specific function while working together to reduce emissions.
Solution Approach 2:
The invention transitions from traditional shallow, wide piston bowls to a deep, narrow three-dimensional geometry with specific depth-to-diameter ratios. This dimensional change creates enhanced fuel-air mixing in the vertical dimension while maintaining compact overall size, achieving emission reductions without sacrificing adaptability.
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 optimized piston bowl design enhances fuel distribution and combustion efficiency, achieving lower soot and NOx emissions, even at higher swirl ratios, making it suitable for smaller engines with improved thermal distribution.
Implementation Method 1
fuel injected into the combustion chamber... fuel injector configured to inject fuel into the combustion cylinder
Implementation Method 2
shape of the combustion chamber and injection characteristics of fuel injected into the combustion chamber... fuel to target a feature of the piston bowl in order to distribute fuel vapour within the bowl
Implementation Method 3
Combustion characteristics within a combustion chamber of an engine... fuel combustion efficiency
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The disclosure provides a piston crown for a piston mountable in a combustion cylinder of an internal combustion engine. The piston crown includes a top annular surface. Radially inside the top annular surface is a piston bowl for guiding fuel injected into the combustion cylinder. The piston bowl includes a frusto-conical lip chamfer surface at a throat of the piston bowl next to the annular surface. In diametric cross-section the lip chamfer surface has a radius of at least 30 mm, preferably 30 mm.