Vehicle Exhaust Pipe Expanded Portion Flow Diffusion
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Solution Overview
Problem
Conventional vehicle exhaust pipes fail to sufficiently purify exhaust gases when the flow velocity of exhaust gas increases, as the gas flow is not evenly distributed across the catalyst carrier, leading to inadequate purification in the peripheral areas.
Innovation Solution
The exhaust pipe design includes expanded portions with a larger diameter on either side of the storage space, which diffuses and slows down the exhaust gas flow, ensuring even distribution across the catalyst carrier for effective purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the flow velocity of exhaust gas in the upstream pipe is increased, then the exhaust gas can be processed faster, but the exhaust gas is not sufficiently diffused in the connection part and most of the exhaust gas flow only near the center of the storage space, causing the catalyst in the peripheral area to hardly function
Solution Approach 1:
The patent introduces a flow diffusion structure as an intermediary component between the upstream exhaust pipe and the storage space. This mediator structure actively diffuses the high-velocity exhaust gas flow, converting it into a more uniformly distributed flow pattern before entering the storage space, thereby ensuring both high processing speed and effective catalyst utilization.
Solution Approach 2:
The patent employs a three-dimensional flow diffusion structure that transforms the one-dimensional axial flow into a multi-dimensional distributed flow. The diffusion structure creates radial and tangential flow components, causing exhaust gas to reach different regions of the storage space simultaneously, including the peripheral areas that would otherwise be underutilized.
2Reliability
If the diameter of the storage space is made larger than the exhaust pipe, then the flow velocity can be reduced for better purification, but the exhaust gas is not sufficiently diffused and flows only near the center
Solution Approach 1:
The patent segments the exhaust gas flow into multiple streams using the flow diffusion structure. Instead of a single concentrated flow path, the diffusion structure divides the flow into numerous smaller flow paths that distribute exhaust gas throughout the storage space, ensuring uniform utilization of the catalyst across the entire peripheral area.
3Device complexity
If the catalyst carrier is placed in the storage space with outer surface contact, then the structure is simple, but the peripheral catalyst hardly functions when flow velocity is high
Solution Approach 1:
The flow diffusion structure serves as an intermediary that actively manages the interaction between exhaust gas and catalyst. It modifies the flow characteristics to ensure proper contact between exhaust gas and the catalyst carrier, maintaining structural simplicity while enhancing catalyst functionality through improved flow distribution.
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 design ensures that exhaust gases are evenly distributed across the catalyst carrier, enhancing purification efficiency even at increased flow velocities, thereby improving overall exhaust gas purification.
Implementation Method 1
a sufficient amount of the exhaust gas which flows into the expanded portion is fully diffused while the flow velocity is decreasing therein
Data Source
AI summary
An exhaust pipe 1 having a circular cross section is connected to a circular cylindrical housing 2 which creates part of pipe conduit. The housing 2 forms a storage space 21 having a diameter larger than the diameter of the exhaust pipe 1 and connecting to the rear connection part 22. The connection part 22 is tapered toward the downstream exhaust pipe 12 and the diameter of the connection part 22 is gradually reduced and its opening is welded into the opening of the downstream exhaust pipe 12. And a cylindrical honeycomb catalyst carrier 3 is stored in the storage space 21 so that the outer surface of the catalyst carrier is in contact with the inner surface of the storage space 21. An expanded portion 23 having a diameter larger than the diameter of the storage space 21 is outwardly expanded from the outer circumference of the housing 2 and connectingly provided on the front face of the storage space 21. The diameter of the expanded portion 23 is gradually reduced toward the upstream exhaust pipe 11 and welded into the opening of the outer wall of the exhaust pipe 11.