Trailer Fairing Design for Drag Reduction
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Solution Overview
Problem
Trailers experience inefficiencies due to their box-shaped geometry and rear door design, which hinder aerodynamic performance, leading to increased drag and reduced fuel efficiency, despite existing solutions like trailer skirts and fairings that only partially address these issues.
Innovation Solution
An apparatus comprising a top fairing and side fairings that engage to form a continuous surface at the back of the trailer, optionally combined with trailer skirts and rear skirts, to enhance aerodynamic performance by managing airflow and reducing drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a box-shaped geometry is used for maximum cargo capacity, then the trailer volume is maximized, but aerodynamic performance deteriorates due to increased drag
Solution Approach 1:
The patent applies curvature by adding a fairing with a curved outer surface at the rear end of the box-shaped trailer. This curved surface modifies the airflow pattern around the trailer, reducing turbulence and drag while preserving the box-shaped cargo volume. The curved fairing surface guides air smoothly over the rear corner, preventing vortex formation and reducing aerodynamic resistance.
Solution Approach 2:
The aerodynamic improvement system is segmented into separate components: a fairing assembly attached to the rear of the trailer, and optional side skirts attached to the sides. This segmentation allows the box-shaped trailer to maintain its maximum volume while adding aerodynamic features as separate, modular components that can be independently optimized.
2Ease of operation
If a large opening is used in the rear door for easy loading and unloading, then ease of operation is improved, but aerodynamic performance deteriorates due to increased drag
Solution Approach 1:
The fairing acts as an intermediary element between the large rear door opening and the airflow. It is attached to the rear end of the trailer, bridging the gap between the cargo opening and the external air stream. The fairing modifies the airflow pattern to reduce drag while allowing the large door opening to remain functional for easy loading and unloading operations.
3Object-affected harmful factors
If trailer skirts are added to limit air circulation between axles, then aerodynamic performance is improved by reducing turbulence drag, but device complexity increases
Solution Approach 1:
The aerodynamic system is divided into separate functional segments: fairings for the rear end and optional side skirts for the sides. This segmentation allows the turbulence-reducing function to be achieved through modular components that can be independently installed and optimized, reducing overall system complexity compared to a monolithic design.
Solution Approach 2:
The side skirts are positioned to extend only partially along the trailer sides, stopping before the rear corner. This partial action is sufficient to reduce turbulence drag in the critical rear region where airflow separation occurs, while avoiding the unnecessary complexity of covering the entire trailer length.
4Object-affected harmful factors
If curved fairings are used to reduce dragging force, then aerodynamic performance is improved, but the ability to stabilize airflow wake structure behind the trailer is insufficient
Solution Approach 1:
The fairing system is segmented into multiple components: a main fairing body and optional side fairings that engage with the main fairing. This segmentation creates a more comprehensive airflow control system that addresses both drag reduction and wake structure stabilization by modifying airflow at multiple locations and angles.
Solution Approach 2:
The optional side fairings add a lateral dimension to the airflow control system. By engaging with the main fairing and extending airflow management to the sides, the system creates a three-dimensional airflow control structure that stabilizes the wake behind the trailer while maintaining the curved surface geometry for drag reduction.
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 solution significantly improves the aerodynamic performance of trailers by stabilizing airflow and reducing drag, resulting in increased fuel efficiency and improved towing performance.
Implementation Method 1
The fairings modify the airflow around or off of the end of the trailer to reduce drag. It is known to produce fairings that have a curved outer surface that extend from the leading edge of the fairing to the tailing edge of the fairing. These curved fairings change the airflow about the end of the trailer to reduce dragging force.
Implementation Method 2
By reducing the amount of airflow in this space, drag caused by turbulence is reduced and permits the trailer to be towed more efficiently
Data Source
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AI summary
An apparatus for a trailer is provided that has a top fairing configured for being mounted to a top surface of the trailer at a location closer to the back of the trailer than the front of the trailer. The trailer has a longitudinal direction, a lateral direction, and a vertical direction. A side fairing is also present and is configured for being mounted to a side surface of the trailer. The top fairing engages the side fairing.