Vehicle Wake Disruptor Reducing Aerodynamic Drag
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Solution Overview
Problem
Existing wake disruptors for land vehicles do not effectively reduce aerodynamic drag by eliminating turbulent airflow vortices at the rear end, instead merely relocating them, which does not significantly improve fuel efficiency.
Innovation Solution
A wake disruptor is designed to protrude outwardly from the rear side of a land vehicle, extending partially or fully across its width, with a length significantly greater than its width and thickness, arranged to disrupt and separate downward airflow, potentially in conjunction with aerodynamic features like skirts and fairings, to reduce drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If prior art wake disruptors are used, then the vortices are relocated towards the bottom side of the vehicle, but the vortices are not reduced and aerodynamic drag is not significantly improved
Solution Approach 1:
The patent changes the geometric parameters of the wake disruptor, specifically using a width-to-length ratio between 0.2 and 0.8 (where width is the dimension parallel to the vehicle rear and length is the dimension perpendicular to the vehicle rear). This parameter optimization allows the disruptor to effectively reduce vortex strength and aerodynamic drag, improving fuel economy by 0.25-2% compared to prior art devices that merely relocated vortices without reducing them.
2Loss of energy
If a wake disruptor protrudes outwardly from the rear side of the vehicle, then turbulent airflow is disrupted and separated, but the device complexity increases
Solution Approach 1:
The wake disruptor is designed as a segmented structure with a rearward-facing surface comprising multiple planar surfaces (first, second, third, and fourth planar surfaces) that collectively form the disruptor geometry. This segmentation allows the complex aerodynamic function to be achieved through simpler, modular geometric elements that can be manufactured and installed more easily than a monolithic complex structure.
3Use of energy by moving object
If the wake disruptor width and length are optimized within specific ratios, then fuel economy is improved by 0.25-2%, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines a specific parameter range for the width-to-length ratio (0.2 to 0.8) that optimizes fuel economy. This parameter specification provides clear manufacturing guidelines that balance performance optimization with manufacturability, allowing standard manufacturing tolerances to achieve the desired aerodynamic effect without requiring ultra-precision fabrication.
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 wake disruptor effectively reduces and separates turbulent airflow, leading to decreased aerodynamic drag and improved fuel efficiency by altering the airflow pattern behind the vehicle, as demonstrated in aerodynamic simulations and wind tunnel tests.
Implementation Method 1
This reduction in pressure results from a turbulent wake that forms behind the trailer (or more generally, the land vehicle) in which there are large and turbulent recirculating areas of airflow, which are known as vortices or eddies
Implementation Method 2
aerodynamic drag comprises more than half of the drag on tractor trailers at interstate speeds. One of the main sources of aerodynamic drag occurs at the rear end of the trailer
Data Source
AI summary
Particular embodiments of the invention comprise a wake disruptor (112) for use on the rear side (102) of a land vehicle (100), a method of using the wake disruptor to reduce drag of a land vehicle, and a land vehicle including the wake disruptor. The wake disruptor forms a protrusion extending outwardly from a rear side of the land vehicle by a distance of 1.5 to 8 inches and has a length extending at least partially in a direction of the vehicle width. The land vehicle may comprise a motorized or powered vehicle and/or a towed object, such as a trailer.