Tractor-Trailer Gap Fairing with Pressure Bubble
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Solution Overview
Problem
Aerodynamic drag at the gap between a tractor and trailer in tractor-trailer combinations leads to increased fuel consumption and pollutant emissions, as existing fairing structures can only achieve modest drag reduction due to size constraints that limit their efficiency.
Innovation Solution
A three-sided airfoil fairing that fills the gap with a pressure bubble, using resilient materials and hinges to accommodate truck movements and heat-resistant materials to prevent damage and fire risks, effectively eliminating or reducing aerodynamic drag by trapping air and preventing wind penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If existing fairing structures are used to reduce drag at the gap between tractor and trailer, then aerodynamic drag is reduced modestly, but the drag reduction efficiency is limited due to size constraints that prevent the fairing from being large enough to fully eliminate the gap
Solution Approach 1:
Instead of trying to direct airflow away from the gap (conventional approach), this invention inverts the strategy by filling the gap with a pressure bubble that prevents air from entering the gap in the first place. The fairing structure creates an over-pressure area that acts as a barrier, stopping airflow at the gap rather than attempting to redirect it after entry.
Solution Approach 2:
The fairing structure introduces an intermediary pressure bubble between the tractor and trailer that mediates the airflow interaction. This pressure bubble acts as a buffer zone that prevents direct air penetration into the gap, effectively decoupling the airflow from the gap region while allowing the fairing to be sufficiently large to eliminate the gap entirely.
2Loss of energy
If the fairing structure is made larger to improve drag reduction efficiency, then aerodynamic drag decreases, but the fairing may interfere with normal truck operations such as turning and pivoting
Solution Approach 1:
The fairing structure incorporates resilient materials and hinges that enable it to dynamically adapt during truck operations. The resilient fairing panels can deform and spring back when the tractor turns or pivots against them, allowing the fairing to be large enough for optimal drag reduction while maintaining full operational flexibility of the truck.
Solution Approach 2:
The fairing employs resilient fairing panels that function as flexible shells, permitting the structure to bend away from obstructions during truck maneuvers and return to its original position. This flexibility allows the fairing to maintain its aerodynamic shape during normal operation while accommodating extreme turning and pivoting movements without interference.
3Ease of operation
If resilient materials are used to allow the fairing to deform during truck movements, then operational flexibility is maintained, but the structural strength may be compromised
Solution Approach 1:
The fairing structure utilizes composite construction combining resilient materials with reinforcing elements. The resilient fairing panels are supported by rigid frames and reinforced with ribs, creating a composite structure that maintains both flexibility for deformation during operations and sufficient strength to withstand aerodynamic forces and physical impacts.
Solution Approach 2:
The fairing is divided into multiple resilient panels that can independently deform during truck movements. This segmentation allows each panel to flex and spring back locally without compromising the overall structural integrity of the fairing, distributing the mechanical stresses across multiple independent elements rather than requiring a single rigid structure.
4Reliability
If heat-resistant materials are used to prevent fire risks from exhaust pipe contact, then safety is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
Heat-resistant materials are applied selectively only to the portions of the fairing structure that are at risk of contact with hot exhaust pipes, rather than using heat-resistant materials throughout the entire fairing. This localized application maintains fire safety in critical areas while simplifying material selection and reducing overall manufacturing complexity for portions of the fairing not exposed to thermal hazards.
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
Significantly reduces aerodynamic drag, fuel consumption, and pollutant emissions while allowing for flexible operation and safety features to prevent damage and fire hazards.
Implementation Method 1
functions by filling the Gap with a 'pressure bubble.' As a result, the Gap ceases to exist and air is prevented from entering the area comprising the Gap and striking the front surface of the trailer box
Data Source
AI summary
A fairing structure for a vehicle having a front vehicular component and a rear vehicular component in tandem and separated by a gap, comprising a top fairing surface adapted to be attached to the rear vehicular component, a first side surface adapted to be attached to a first side of the rear vehicular component, joining a first end of the top surface and generally perpendicular to the top surface, and a second side surface adapted to be attached to a second side of the rear vehicular component, joining a second end of the top surface opposite the first end and generally perpendicular to the top surface. Each of the top and first and second side surfaces has a proximal edge adapted to be positioned adjacent a vehicle, as well as a distal edge adapted to be positioned away from the vehicle with respect to the respective proximal edge. The proximal edges of the top and side surfaces attach to the leading top and side edges, respectively, of the front surface of the trailer box, so that an approximately uninterrupted surface is formed from the fairing structure to top and sides of the rear vehicular component. The area bounded by the distal edges of the surfaces is smaller than an area bounded by the proximal edges.