Ventilation Duct Layout for Low-Noise Split Airflow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ventilation devices for vehicles suffer from noise issues due to high overspeeds caused by the Coanda effect, which reduces the aeraulic section and necessitates bulky, complex, and noisy deflection mechanisms, limiting the integration of control elements.
Innovation Solution
A ventilation device design featuring a main conduit with a fixed part upstream of a hollow core that divides air flows into two channels without inducing Coanda effect, combined with fins and flaps for controlling air orientation, reducing pressure loss and noise while maintaining compactness and allowing for multiple control elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a hollow Coanda effect core is used to integrate control members, then the number of integrated control members increases, but the airflow section is reduced causing high overspeeds and noise
Solution Approach 1:
The invention extracts the flow division function from the hollow core by introducing a separate fixed part upstream. This allows the hollow core to be widened for integrating more control members without compromising airflow section, as the fixed part performs the flow splitting task that previously required the core to be narrow
Solution Approach 2:
The invention segments the ventilation device into distinct functional components: a fixed part for flow division, a hollow core for control member integration, and a rounded rear wall for flow guidance. This segmentation allows each component to be optimized independently - the fixed part handles airflow division while the hollow core focuses on housing control members
2Adaptability or versatility
If a hollow Coanda effect core is used to integrate control members, then the device becomes more versatile, but the device complexity increases
Solution Approach 1:
The invention divides the device into modular segments with clear functional boundaries: the fixed part for flow division, the hollow core for control integration, and the rounded rear wall for guidance. This modular segmentation reduces overall complexity by making each component's function explicit and independent
3Speed
If Coanda effect guidance is used, then air flow attachment to surfaces is achieved, but significant pressure loss occurs due to reduced airflow section
Solution Approach 1:
The invention removes the flow division function from the Coanda effect core and places it in a separate fixed part upstream. This extraction allows the core to maintain a larger cross-section for pressure preservation while the fixed part handles the flow splitting, eliminating the need to reduce core dimensions
Solution Approach 2:
The fixed part performs flow division preliminarily before the air reaches the hollow core. This preliminary action ensures that flow division occurs in a zone with sufficient pressure, preventing pressure loss that would occur if division happened at the constricted core section
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
Significantly reduces flow noise and allows for a larger number of integrated control members without compromising device compactness, enhancing both noise reduction and aesthetic appeal.
Implementation Method 1
a fixed part which is arranged so as to divide the air coming from the installation into two air flows
Implementation Method 2
a rear wall receiving the divided air flows and having a rounded shape suitable for guiding the latter respectively towards the secondary ducts
Implementation Method 3
fins, installed between the fixed part and the rear wall of the hollow core, suitable for controlling the orientation in a second plane of the divided air flows
Implementation Method 4
Thanks to the flow division achieved by the fixed part in an upstream zone relatively far from the hollow core, there is virtually no pressure loss when the divided and guided air flows join the two secondary ducts respectively
Implementation Method 5
This (almost) absence of pressure loss combined with the absence of Bernoulli and Venturi effects (due to the absence of Coanda effect) makes it possible to significantly reduce flow noise
Data Source
Figure 1
Figure 2
AI summary
Ventilation device (DA) fitted in a heating and/or air conditioning unit supplying air to an enclosed space (E), and comprising a main duct (CP) supplied with air by the unit, housing a fixed part (PF) dividing said air into two air streams, and supplying air to two secondary ducts (CS1-CS2) supplying the enclosed space (E), a hollow core (NC) defining two sub-portions of the secondary ducts (CS1-CS2) and comprising a rear wall (PR) receiving the divided air streams and having a rounded shape suitable for guiding the latter to the secondary ducts (CS1-CS2), respectively, and a front wall (PV) located in the enclosed space (E) and control members (OCk), which are installed in the hollow core (NC), can be accessed via the front wall (PV) and enable the device (DA) and at least one portion of the unit to be controlled.