Air Outlet Deflector Layout for Stable Coanda Airflow Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional air blowout apparatuses face challenges in maintaining a stable air volume in both the first and second states due to the diffusion of air from the blowing port, which affects the air volume direction, and existing solutions like protrusions can reduce air volume in one state while increasing it in the other.

Innovation Solution

The air blowout apparatus employs a duct with a butterfly door and a cantilever door to generate two air flows with different flow rates, utilizing the Coanda effect to stabilize air volume by adjusting the flow rates and bending angles through guide walls, ensuring consistent air distribution regardless of the state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If air flow is diffused from the blowing port to increase bending angle, then the air flow direction control is improved, but the air volume in the direction from the second wall toward the first wall becomes unexpectedly small

Engineering Contradiction:
Improvebending angleVSAvoidair volume in direction from second wall toward first wall
Core Design Contradiction:
ShapeVSQuantity of substance

Solution Approach 1:

The patent changes the geometric parameter of the duct by introducing a protrusion portion on the second wall. This structural parameter change modifies the flow characteristics to increase both the bending angle and the air volume in the direction from the second wall toward the first wall simultaneously, resolving the contradiction between flow direction control and volume maintenance

Inventive Principle:
Principle #35Parameter changes

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

The apparatus maintains a stable air volume and adjustable bending angles, allowing for precise control of air direction and distribution in various modes, enhancing air conditioning efficiency and comfort in vehicle interiors.

Implementation Method 1

a part of the first wall on the blowing port side configures a guide wall for guiding the air flow at the high flow rate such that the air flow at the high flow rate from the first flow channel, which is generated by the air flow deflection member is bent along the wall surface, and the direction of the air flow at the high flow rate matches a direction from the second wall toward the first wall

Methodology Applied
Scientific EffectCoanda effect: Coanda Effect

Data Source

PatentEP3498507B1Air blowout apparatus
Publication Date: 2025.08.06 DENSO THERMAL SYST SPA
  • EP3498507B1 patent drawingFigure 1
  • EP3498507B1 patent drawingFigure 2
  • EP3498507B1 patent drawingFigure 3

AI summary

A first air flow (F1) is produced between a first air flow deflection member (13) and a first wall (121). A second air flow (F2) is produced between the first air flow deflection member and a second wall (122). The first air flow deflection member switches between a first state, in which the first air flow is higher in flow rate than the second air flow, and a second state, in which an air flow different from the airflow in the first state is produced. A guide wall (14), which is a part of the first wall on a blowing port side, bends the first air flow in the first state along a wall surface and guides the first air flow to direct the first air flow in a direction from the second wall toward the first wall. A second air flow deflection member (15) is located on an air flow downstream side of the first air flow deflection member. The second airflow deflection member deflects the second airflow in the direction from the second wall toward the first wall in the first state. In the second state, the second air flow deflection member reduces the degree of deflection of the second air flow in the direction from the second wall toward the first wall, or inhibits deflection of the second air flow in the direction from the second wall toward the first wall, compared to the first state.