Cylinder Flow Deflector for Combustion Deposit Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face issues with fuel and combustion products interacting with engine structures within the cylinder, leading to deposits and reduced durability, particularly in the thin space between the piston and cylinder above the topmost piston ring seal.
Innovation Solution
The implementation of a deflector structure, either concave or convex, is positioned between the topmost ring seal groove and the flame deck to deflect combustion products and fuel plumes away from the piston and cylinder walls, preventing deposition of material in areas not scraped by the ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a deflector structure is added to prevent fuel and combustion products from contacting engine structures, then deposit formation is reduced and engine durability is enhanced, but device complexity increases
Solution Approach 1:
A deflector structure is introduced as an intermediary element positioned between the combustion chamber and the piston crown/cylinder wall interface. This deflector intercepts fuel and combustion products, redirecting them away from areas prone to deposit accumulation, thereby protecting engine structures without requiring fundamental redesign of the combustion system
Solution Approach 2:
The cylinder interior space is segmented into distinct zones by the deflector structure. The deflector creates a separation between the high-temperature combustion region and the vulnerable piston crown/cylinder wall interface, allowing different flow patterns and temperature distributions in each zone to minimize harmful interactions
2Reliability
If the deflector structure is positioned to maximize protection of the piston and cylinder walls, then deposit formation is minimized, but the available variable volume for combustion is reduced
Solution Approach 1:
The deflector structure is strategically positioned and dimensioned to provide protection only in the specific regions where deposit formation is most problematic (piston crown and cylinder wall interface), while leaving the bulk of the combustion chamber volume unchanged. This localized approach ensures protection where needed without significantly compromising overall combustion volume
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 solution effectively minimizes the interaction of fuel and combustion products with engine structures, reducing the formation of deposits and enhancing engine durability by redirecting these components back into the combustion chamber.
Implementation Method 1
The deflector structure is disposed between the topmost ring seal groove and the flame deck to deflect combustion products and fuel plumes away from the piston and cylinder walls
Data Source
AI summary
An internal combustion engine includes a cylinder case forming a cylinder bore having a centerline and an inner bore surface. A piston disposed within the cylinder bore forms a crown surface. A region defined between the piston and the cylinder bore in a radial direction has an annularly shaped mouth opening surrounding the crown surface. A cylinder head is disposed to cover an open end of the cylinder bore such that a variable volume is defined within the cylinder bore between the cylinder head and the piston. The cylinder head also forms a flame deck in fluid contact with the variable volume. A deflector structure forms a portion of the inner bore surface adjacent the flame deck surface, and is disposed between the flame deck and a topmost ring seal groove of the piston when the piston is at a TDC position.