Honeycomb Metal Substrate Burr Geometry for Low Pressure Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing honeycomb-type metal substrates for catalytic converters generate excessive turbulence, leading to increased pressure loss and decreased fuel efficiency, despite efforts to enhance emission control performance.
Innovation Solution
A honeycomb-type metal substrate is formed by alternately layering metal flat and corrugated foils with controlled hole diameters, aperture ratios, and burr heights, where burrs with small heights and orthogonal tip end surfaces are formed to minimize turbulence while maintaining emission control performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If projections are formed at opening edges of holes to induce turbulence, then emission control performance is enhanced, but pressure loss increases and fuel efficiency deteriorates
Solution Approach 1:
The invention changes the geometric parameters of the hole structure by forming burrs with specific height constraints (0.01mm ≤ L ≤ 5.0mm) and controlling the aperture ratio (5% ≤ R ≤ 70%) and hole diameter (1.1mm ≤ D ≤ 4.0mm). These parameter optimizations allow the burrs to generate necessary turbulence for emission control while limiting excessive turbulence that would cause pressure loss.
Solution Approach 2:
The burrs are formed locally at the opening edges of holes rather than as continuous projections. This localized structure provides turbulence generation at critical points where exhaust gas flows through holes, while avoiding excessive turbulence in other regions, thus balancing emission control performance with pressure loss reduction.
2Reliability
If turbulence is generated to enhance emission control performance, then catalyst activation is improved, but pressure loss increases
Solution Approach 1:
The burr height L is precisely controlled within 0.01mm to 5.0mm to generate adequate turbulence for catalyst activation without creating excessive pressure loss. The aperture ratio R (5%-70%) and hole diameter D (1.1mm-4.0mm) are also optimized to balance turbulence generation with flow resistance.
3Productivity
If hole diameter and aperture ratio are increased to improve flow characteristics, then substance exchange is enhanced, but turbulence control becomes difficult
Solution Approach 1:
The invention establishes specific ranges for hole diameter (1.1mm ≤ D ≤ 4.0mm) and aperture ratio (5% ≤ R ≤ 70%) that simultaneously optimize substance exchange efficiency and turbulence control. These parameter boundaries ensure adequate flow characteristics while maintaining manageable turbulence levels through the burr structure.
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 substrate achieves enhanced emission control performance by suppressing excessive turbulence and reducing pressure loss, allowing for early activation of catalytic reactions even at low exhaust gas temperatures.
Implementation Method 1
a plurality of holes are formed in a metal flat foil and a metal corrugated foil, a burr having a small height being formed on an edge of each hole
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
[Problem] To improve purification performance in a honeycomb-type metal substrate while suppressing excessive generation of turbulence. [Solution] A honeycomb-type metal substrate in which flat metal foils and wavy metal foils are alternately layered, wherein: a plurality of holes are formed in the flat metal foil and in the wavy metal foil, and small burrs are formed on the edges of the holes; and the relationships 1.1 mm ≤ D ≤ 4.0 mm, 5% ≤ R ≤ 70%, and 0.1 µm ≤ L ≤ 30 µm are satisfied, where D is the average hole diameter of the plurality of holes, R is the opening rate, and L is the average height of the burrs.