Engine Intake Air Duct Noise Reduction via Reflecting Wall
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Solution Overview
Problem
Existing engine intake air ducts face challenges in reducing noise in the frequency range of 600 to 2000 Hz while maintaining low pressure loss and a compact size, as conventional noise reduction methods either increase pressure loss or enlarge the duct size.
Innovation Solution
The engine intake air duct features a curved intake portion merging smoothly with a straight main duct portion, incorporating a reflecting wall and reinforcement structures to minimize noise reflection and pressure loss, with specific dimensions and shapes optimizing airflow and noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional resonators or noise reduction devices are added to reduce engine noise, then noise reduction effectiveness is improved, but pressure loss increases and device size enlarges
Solution Approach 1:
The patent integrates the noise reduction function directly into the air duct structure by forming a resonating cavity within the duct walls, merging the airflow passage and noise reduction components into a single integrated structure. This eliminates separate noise reduction devices that would increase pressure loss and device complexity.
Solution Approach 2:
The air duct is designed to serve multiple functions simultaneously: it guides airflow to the engine while its integrated resonating cavity structure provides noise reduction across multiple frequency bands (80-600 Hz and 600-2000 Hz), making the duct itself a multi-functional component rather than adding separate specialized devices.
2Object-affected harmful factors
If conventional resonators or noise reduction devices are added to reduce engine noise, then noise reduction effectiveness is improved, but device complexity and size increase
Solution Approach 1:
The noise reduction function is merged into the air duct structure itself through integrated resonating cavities formed within the duct walls. This eliminates the need for separate resonators or noise reduction devices, simplifying the overall system while maintaining noise reduction effectiveness across multiple frequency bands.
3Object-affected harmful factors
If the duct is designed to reduce noise in the 600 to 2000 Hz frequency band, then external vehicle noise regulation compliance is improved, but pressure loss and device size increase
Solution Approach 1:
The air duct is designed with resonating cavities that provide noise reduction across multiple frequency bands (80-600 Hz and 600-2000 Hz) simultaneously, making the duct itself a multi-functional component that complies with external noise regulations without requiring separate specialized devices that would increase pressure loss.
Solution Approach 2:
The noise reduction function for multiple frequency bands is merged into the air duct structure through integrated resonating cavities, eliminating the need for separate noise reduction devices that would increase pressure loss and device complexity.
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 configuration effectively reduces noise across a wide frequency band (600 to 2000 Hz) while maintaining low pressure loss and a compact size, enhancing air intake efficiency and reducing external noise levels.
Implementation Method 1
a reflecting wall configured to reflect a sound from the vehicle air cleaner is provided at an end face of the extending portion so as to intersect the second center line
Data Source
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AI summary
An engine intake air duct 1 has an intake portion 10 that extends along a first center line A, and a main duct portion 20 that extends along a second center line B. The main duct portion 20 has a merging portion 50, a discharge opening 21, and an extending portion 40 that extends from the merging portion 50 towards an opposite end to the discharge opening 20. A reflecting wall 41 is provided at an end face of the extending portion 40. The intake portion 10 merges with the main duct portion 20 in such a way that the first center line A is directed towards a downstream end of the main duct portion 20.