Combustion Chamber Wall Inlet Structure for Homogeneous Swirl
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing combustion chamber designs for heating devices in vehicles face challenges in generating homogeneous swirl for efficient and low-emission combustion, leading to increased manufacturing costs, material usage, and undesirable weight gain, while also suffering from burr formation and the Coandé effect that limits mixing efficiency.
Innovation Solution
A combustion chamber wall design featuring a relief cut and forming section in the circumferential wall to create inlet openings, allowing for a tangential and radial flow component, eliminating burr formation and enhancing swirl generation for improved mixing without the Coandé effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If tangentially oriented bores are used to generate swirl, then swirl generation is improved, but circumferential wall thickness must be increased leading to weight gain and increased material usage
Solution Approach 1:
The inlet opening is divided into two functional parts: a relief cut that creates the opening and a forming section that generates swirl. This segmentation allows the swirl generation function to be integrated into the wall structure itself rather than requiring separate thick-walled components or additional swirl-generating elements.
Solution Approach 2:
The relief cut and forming section are combined into a single integrated structure in the circumferential wall. The forming section is shaped radially towards the central axis and is directly adjacent to the relief cut, merging the opening creation and swirl generation functions into one unified component that works within thin-walled structures.
2Device complexity
If tab-like pressed-in air inlet openings are used, then swirl generation is achieved in thin walls, but burr formation occurs reducing flow area and affecting combustion conditions
Solution Approach 1:
The relief cut is formed as a preliminary step before the forming section is created. By establishing the opening first through the relief cut, the subsequent forming process can shape the edges properly without creating burrs, as the opening geometry is pre-defined and the forming section is then shaped radially towards the central axis in a controlled manner.
3Ease of manufacture
If pressing tool and counter-stop are used to form tabs, then inlet openings are created, but the cutting process tears material and creates burrs requiring inspection
Solution Approach 1:
The traditional mechanical pressing tool and counter-stop system is replaced with a forming process that shapes the wall material radially towards the central axis. This forming action creates the inlet opening and swirl-generating edges without the tearing and burr formation characteristic of cutting operations, eliminating the need for subsequent inspection.
4Ease of operation
If tangentially oriented opening area is used, then air flows along circumferential wall, but Coandé effect causes flow to remain in radially outer region limiting mixing
Solution Approach 1:
The forming section is shaped asymmetrically radially towards the central axis, creating an asymmetric geometry that disrupts the symmetric Coandé effect. This asymmetric shaping causes the flow to be directed more effectively into the combustion chamber center region, improving mixing homogeneity across 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
The design achieves cost-effective, efficient, and weight-reduced swirl generation with homogeneous mixing across the combustion chamber, reducing manufacturing complexity and eliminating the need for additional inspections.
Implementation Method 1
a formed section (54) in the circumferential wall (44), which is shaped in a radial direction towards the central axis... The formed section (54) is shaped radially towards the central axis in order to generate a swirl in the introduced air flow
Implementation Method 2
eliminating burr formation and enhancing swirl generation for improved mixing without the Coandé effect
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A combustion chamber wall for a combustion chamber assembly (100) of a heating device (1) in a vehicle is configured to form a combustion chamber (8). It comprises a cylindrical circumferential wall (44) which defines a central axis (C) extending in the axial direction (X). At least one structure (22) for introducing an oxidizer into the combustion chamber (8) is formed in the circumferential wall (44). The structure comprises a relief (52) formed in the circumferential wall, which forms an inlet opening, and a formed section (54) formed in the circumferential wall (44), which is shaped in a radial direction (R) towards the central axis (C). The relief (52) adjoins the formed section (52) shaped towards the central axis (C) directly in a circumferential direction (P) of the circumferential wall (44).