Handlebar Wake Promotion for Drag Reduction
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Solution Overview
Problem
Existing handlebars on vehicles, such as bicycles, suffer from significant profile drag due to boundary layer separation, leading to high total drag forces that increase energy consumption and reduce comfort for the operator.
Innovation Solution
The handlebar design incorporates wake promotion and non-wake promotion portions with specific surface profiles and orientations to direct airflow, promoting wake formation upstream of the operator and reducing drag forces by controlling boundary layer separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the handlebar has a circular profile, then the manufacturing is simple and familiar, but the profile drag is significant due to boundary layer separation
Solution Approach 1:
The handlebar is designed with different cross-sectional shapes at different locations: a circular profile at the ends for ease of manufacture and gripping, and a non-circular profile in the middle section to promote wake formation and reduce drag. This local differentiation allows each section to serve its specific function while resolving the contradiction between manufacturing simplicity and drag reduction.
2Object-affected harmful factors
If the handlebar is aerodynamically shaped, then the form drag is reduced, but the total drag force reduction is insignificant
Solution Approach 1:
The invention intentionally promotes wake formation behind the handlebar by using a non-circular cross-sectional shape. Although wake formation typically increases drag on the handlebar itself, the wakes generated interfere with the larger wake that would form behind the cyclist's legs, thereby reducing the total drag force on the cyclist-handlebar system. This converts the harmful effect of wake formation into a beneficial one at the system level.
3Loss of energy
If the handlebar promotes wake formation, then the combined total drag is reduced, but the wake may affect operator comfort
Solution Approach 1:
The handlebar is segmented into different sections with different cross-sectional shapes: circular sections at the ends and a non-circular section in the middle. This segmentation allows the wake-promoting non-circular section to be positioned specifically to generate wakes that redirect away from the operator's body, while the circular end sections maintain comfort and control. The segmentation enables spatial separation of wake generation from operator exposure.
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 the combined total drag force on the handlebar, vehicle, and operator, enhancing energy efficiency and comfort by directing wakes away from the operator, thereby minimizing form drag.
Implementation Method 1
a problem with such handlebars is that they tend to suffer from significant profile drag due to boundary layer separation
Implementation Method 2
the transverse support comprises a first wake promotion portion configured to promote wake formation downstream thereof
Implementation Method 3
the form drag acting on an object arises due to separation of a boundary layer from a surface of that object, and is highly dependent on the object's shape
Data Source
AI summary
A handlebar for controlling a travelling direction of a vehicle. The handlebar comprises: an elongate transverse support for mounting to a vehicle, the transverse support extending substantially along a transverse axis between a first end thereof and a second end thereof; wherein the transverse support comprises a first wake promotion portion configured to promote wake formation downstream thereof relative to one or more adjacent non-wake promotion portions of the transverse support when air flows over the handlebar in a flow direction substantially perpendicular to the transverse axis.