Honeycomb Ceramic Substrates with Concave Flow Channels
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Solution Overview
Problem
Honeycomb ceramic substrates used in the automotive industry for emission reduction face challenges in optimizing flow channel structures to minimize corner coating build-up and maximize open frontal area and strength, which affects their performance.
Innovation Solution
The development of honeycomb ceramic substrates with flow channels defined by intersecting walls featuring concave inner surfaces and corner portions, optimized using a die with die pins arranged in a specific curvature equation (xan+ybm=1), allowing for elliptical flow channels that minimize corner coating and enhance strength and flow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional rectangular flow channels are used, then manufacturing is simple, but corner coating build-up increases and coating efficiency decreases
Solution Approach 1:
The patent applies curvature by transitioning from rectangular flow channels with sharp corners to channels with rounded corners and concave inner surfaces. This curvature eliminates corner coating build-up by removing the geometric features that cause coating accumulation, while maintaining manufacturing feasibility through extrusion processes that can produce curved geometries.
Solution Approach 2:
The patent implements local quality by introducing concave inner surfaces specifically at the corner regions of the flow channels, while the straight portions of the channel walls maintain their original geometry. This localized modification targets the specific problem area (corner coating build-up) without unnecessarily complicating the entire channel structure.
2Manufacturing precision
If concave inner surfaces with high curvature are used, then corner coating build-up is minimized, but manufacturing complexity increases
Solution Approach 1:
The patent uses parameter changes by defining the concave inner surface geometry through mathematical equations with adjustable parameters (such as radius of curvature, depth of concavity, and transition zone length). This allows optimization of the concave profile to achieve coating uniformity while controlling the complexity of the die structure used to manufacture it.
3Manufacturing precision
If flow channel shape is optimized for coating efficiency, then open frontal area may be reduced, but overall performance improves
Solution Approach 1:
The concave modifications are applied locally at corner regions rather than uniformly across the entire channel cross-section. This localized approach minimizes the impact on open frontal area while concentrating the coating efficiency improvements where they are most needed (at the corners where coating build-up previously occurred).
Data Source
AI summary
A honeycomb ceramic substrate, a method of making thereof, and a honeycomb extrusion die configured to extrude a honeycomb ceramic substrate from a batch of ceramic or ceramic-forming material is provided. The substrate may include a lattice of intersecting walls defining a honeycomb network of flow channels extending between an inlet end and an outlet end of the honeycomb substrate. Each flow channel may be defined by a plurality of channel walls of the intersecting walls with at least two of the plurality of channel walls including concave inner surfaces facing a center of the corresponding flow channel from central portions of the concave inner surfaces to concave corner portions facing the center of the corresponding flow channel.