Vehicle Side Section Flow Correction Fin for Stability

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Solution Overview

Problem

Existing vehicle body structures lack effective flow correction mechanisms on the upper portion, leading to instability and increased air resistance, particularly when subjected to side winds, as traditional flow correction fins are designed for lower portions and convex bumps on roofs can decrease steering performance.

Innovation Solution

A side section structure with a flow correction fin on the vehicle's side section, featuring a longitudinal length greater than vertical length, with inclined portions and a ridge line, and an inflection portion at the rear end, to correct fluid flow and increase speed, thereby improving stability and reducing air resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a flow correction fin is provided on the lower portion of the vehicle body, then the flow of fluid at the lower portion is corrected and vehicle stability is improved, but the structure cannot be provided on the upper portion of the vehicle body

Engineering Contradiction:
Improvevehicle stabilityVSAvoidapplicability to upper portion
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The flow correction fin is designed with specific local characteristics including a leading edge portion, a suction side surface, and a pressure side surface that are optimized for the upper portion flow conditions. The fin's cross-sectional shape and surface curvature are tailored to effectively correct flow separation at the upper vehicle portion, demonstrating local quality adaptation to the specific location's aerodynamic requirements.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If a convex bump is provided on the roof, then air resistance is decreased, but when subjected to side wind, steering performance and stability are decreased

Engineering Contradiction:
Improveair resistanceVSAvoidsteering performance
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The flow correction fin is segmented into distinct functional portions: a leading edge portion for flow attachment, a suction side surface for maintaining low pressure, and a pressure side surface for flow control. This segmentation allows each portion to independently address specific aerodynamic challenges, reducing overall air resistance while maintaining steering stability through coordinated action of the segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flow correction fin extends in the width direction of the vehicle body, adding a dimensional element that spans across the upper portion. This width-directional extension allows the fin to effectively manage flow across a broader area, reducing air resistance without creating the steering interference problems associated with roof-mounted convex bumps.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Force

If the mainstream of the airstream is far away from the vehicle body, then the aerodynamic force is decreased, but the boundary layer is thickened

Engineering Contradiction:
Improveaerodynamic forceVSAvoidboundary layer thickness
Core Design Contradiction:
ForceVSLength of stationary object

Solution Approach 1:

The flow correction fin acts as an intermediary element between the free stream and the vehicle body surface. It mediates the flow transition by providing a controlled path that maintains flow attachment and prevents excessive boundary layer growth, thereby preserving aerodynamic force while managing boundary layer thickness through its intermediate positioning and geometry.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 flow correction fin on the side section effectively corrects fluid flow on the upper portion, enhancing vehicle stability and steering performance while reducing air resistance, even under side wind conditions.

Implementation Method 1

the flow of fluid in the vicinity of the flow correction fin can be corrected, and the flow speed in the vicinity of the flow correction fin or at the rear side of the fin can be increased

Methodology Applied
Scientific EffectFluid flow correction: Boundary Layer

Data Source

PatentEP3037329B1Vehicle side section structure
Publication Date: 2018.08.15 TOYOTA JIDOSHA KK
  • EP3037329B1 patent drawingFigure 1(a)~1(b)
  • EP3037329B1 patent drawingFigure 2(a)~2(b)
  • EP3037329B1 patent drawingFigure 3(a)~3(b)

AI summary

An object of the present invention is to provide a moving body side section structure capable of correcting a flow of fluid on the upper portion of a moving body and improving stability of the moving body. In a moving body side section structure that includes a flow correction fin 1A that is provided on a side section of a moving body and corrects a flow of fluid of the side section of the moving body, the length of the flow correction fin 1A in a longitudinal direction of the moving body is set so as to be longer than the length of the fin in a vertical direction of the moving body, the flow correction fin includes a first inclined portion 1Ae which is formed at a front end portion in the longitudinal direction of the moving body and in which a width in a width direction of the moving body is widened toward a rear side in the longitudinal direction of the moving body, and a second inclined portion 1Af which is formed further rearward than the first inclined portion 1Ae in the longitudinal direction of the moving body and in which the width in the width direction of the moving body is narrowed toward the rear side in the longitudinal direction of the moving body, a ridge line lAb that connects a front end portion and a rear end portion in the longitudinal direction of the moving body is provided, and an inflection portion 1Ac that discontinuously narrows the width in the width direction of the moving body in the rear end portion may be set.