Pneumatic Tire Side Wall Recesses Protrusions Aerodynamics
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Solution Overview
Problem
Conventional pneumatic tires experience non-uniform air flow and increased air resistance when mounted on vehicles with fenders, which negatively affects fuel economy.
Innovation Solution
The pneumatic tire design incorporates a combination of recesses and protrusions on the tire side portions, with recesses on the outer side in the tire radial direction to generate turbulent flow and suppress air expansion, and protrusions on the inner side to further reduce air resistance by rectifying and expelling air backward, optimizing air flow around the tire.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If recesses are provided on the outer side of the tire radial direction to generate turbulent flow, then air resistance is reduced, but the tire structure becomes more complex
Solution Approach 1:
The tire side surface is segmented into multiple functional zones: an outer region with recesses for generating turbulent flow and suppressing separation, and an inner region with protrusions for rectifying flow. This segmentation allows each region to perform its specific aerodynamic function independently, reducing overall air resistance while maintaining a manageable structural complexity through systematic zoning.
Solution Approach 2:
Different local qualities are applied to different regions of the tire side surface. The outer region features recesses with specific depth and width ratios optimized for turbulent flow generation, while the inner region features protrusions with dimensions optimized for flow rectification. This local differentiation ensures that each area contributes optimally to air resistance reduction without requiring complex modifications throughout the entire tire structure.
2Use of energy by moving object
If protrusions are added to rectify and expel air flow, then fuel economy is enhanced, but manufacturing complexity increases
Solution Approach 1:
The protrusions are designed to preliminarily rectify the air flow before it reaches the turbulent separation zone. By pre-conditioning the flow in the inner region, the subsequent turbulent flow generated in the outer region becomes more controlled and effective at reducing drag, thereby enhancing fuel economy. The protrusions are integrated into the tire molding process, maintaining ease of manufacture through a single-step formation.
Solution Approach 2:
The recesses and protrusions are merged into a unified aerodynamic system where the inner protrusions work in conjunction with the outer recesses. The protrusions expel air backward while the recesses generate turbulent boundary layers, and these two functions are combined to achieve synergistic drag reduction. This merging allows the tire to achieve enhanced fuel economy through a coordinated aerodynamic design that can be manufactured as an integrated structure.
3Stability of the object's composition
If the region with recesses is positioned in the outermost radial direction, then separation of air flow is suppressed, but the tire side profile becomes more complex
Solution Approach 1:
The aerodynamic control is extended from the traditional tread surface into the radial dimension by incorporating recesses and protrusions on the tire side surface. The recesses are positioned at specific radial depths and circumferential locations to create three-dimensional turbulent flow structures that suppress separation. This dimensional extension allows effective flow control while maintaining a relatively simple overall tire profile, as the aerodynamic features are integrated into the existing side wall geometry.
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 design significantly reduces air resistance and enhances fuel economy by creating a turbulent flow boundary layer and expelling air backward, particularly when the tire is mounted within a fender, leading to improved aerodynamic performance.
Implementation Method 1
the air can be made turbulent by the recesses by providing the region including the recesses in an outermost side in a tire radial direction... a turbulent flow boundary layer is generated in the region including the recesses and the expansion of passing air is suppressed
Implementation Method 2
the protrusions rectify the flow of air for which separation was suppressed by the recesses, and expel the flow of air to the back of the tire
Data Source
AI summary
A pneumatic tire is provided including a plurality of protrusions and a plurality of recesses of at least one tire side portion. A region including the recesses is provided in the outermost side in a tire radial direction. The protrusions are formed as convexities having a longitudinal shape in a predetermined direction. A region including the protrusions is provided inward in the tire radial direction of the region including the recesses.