Downstream Cross-Section Adjustment for Quiet Ventilation Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ventilation devices with volume flow control mechanisms often experience noise issues, particularly whistling or cutting noises, due to partial air passage opening, which compromises acoustic comfort and inconspicuous operation.
Innovation Solution
The cross-section adjustment element is positioned downstream of the air guiding element, allowing for adjustable flow cross-sections from 0 to 100%, reducing noise by minimizing through-flow noise occurrences and enabling quiet operation through precise control of air flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cross-section adjustment element is positioned upstream of the air guiding element to control flow, then the flow cross-section can be adjusted, but through-flow noises occur particularly when the air passage is partially opened
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the cross-section adjustment element downstream of the air guiding element rather than upstream. This reversal changes the flow characteristics: instead of creating turbulence at the throat area where partial opening occurs, the adjustment element now operates in a region where the flow has already passed the critical constriction point, significantly reducing whistling and cutting noises while maintaining flow control functionality.
2Productivity
If the air passage is partially opened to reduce air volume flow, then the ventilation can be controlled, but annoying whistling or cutting noises occur in frequency ranges sensitive to the human ear
Solution Approach 1:
The patent converts the potentially harmful partial opening condition into a beneficial arrangement. By placing the adjustment element downstream, the partial opening no longer creates turbulent flow at the constriction point. Instead, the adjustment element smoothly modifies the already-established flow, transforming what would be a noise-generating situation into a quiet, controlled flow condition that maintains ventilation effectiveness.
3Productivity
If the cross-section adjustment element is arranged to block the air outlet, then the air volume flow can be reduced, but the noise levels increase due to turbulent flow
Solution Approach 1:
The patent applies preliminary action by establishing a smooth, guided flow pattern through the air guiding element before the flow reaches the cross-section adjustment element. This preliminary flow conditioning ensures that when the adjustment element blocks or reduces the outlet, the flow remains laminar and controlled rather than turbulent, preventing noise generation even at reduced flow rates.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The flow control device (1) has an air guide element (2) arranged downstream and having a nozzle-shaped air passage (4) cooperating with a cross-section adjusting element (3). The air guide element and the cross-section adjusting element are arranged in mutually displaceable manner. The cross-section adjusting element is arranged to adjust the cross-sections of several air passages and/or the flow-through openings (11) having different dimensions and/or shapes, such that their cross-sections are different from each other. An independent claim is included for ventilation device used in building.