Movable Rear Apron Air Guide for Vehicle Aerodynamics
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Solution Overview
Problem
Existing motor vehicle designs suffer from inefficient airflow around the rear, leading to turbulence and energy loss due to high-energy flow vortices and reduced ground clearance when using traditional air guiding devices like diffusers and spoilers.
Innovation Solution
A rear apron with an air guiding device that can change its contour by moving side sections away from the apron and extending backwards, forming a U-shaped extension, utilizing a transmission device for pivoting movements to enhance aerodynamics and reduce vortex formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional air guiding devices like diffusers and spoilers are used, then aerodynamic performance is improved, but ground clearance is reduced
Solution Approach 1:
The air guiding device is designed to be movable between a retracted position (maintaining ground clearance) and an extended position (improving aerodynamics). The device can be dynamically adjusted based on driving conditions, allowing the vehicle to optimize between ground clearance and aerodynamic performance rather than being fixed in one configuration.
Solution Approach 2:
The air guiding device is divided into a base section and side sections that can move independently. The side sections are pivotably connected to the base section, allowing them to be extended laterally and rearward to form vortex-generating structures without requiring the entire device to extend downward, thus preserving ground clearance while achieving aerodynamic benefits.
2Object-generated harmful factors
If air guiding devices extend downwards towards the roadway, then vortex formation is reduced, but rear ramp angle is reduced
Solution Approach 1:
Instead of extending the air guiding device primarily in the vertical dimension (downward towards the roadway), the invention extends the side sections in the lateral dimension (away from the vehicle body) and rearward. This dimensional shift allows the device to intercept and guide airflow horizontally, reducing vortices without compromising the rear ramp angle required for loading and ground clearance.
3Loss of energy
If side sections are moved away from the rear apron, then aerodynamic flow separation is improved, but device complexity increases
Solution Approach 1:
The side sections are extracted as separate, pivotably connected components from the fixed rear apron structure. This allows them to be moved independently to optimal positions for flow separation control without requiring complex integrated mechanisms. The pivotable connection simplifies the overall mechanism compared to fully articulated or hydraulically actuated systems.
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 configuration significantly improves aerodynamics by promoting energetically favorable flow separation and reduces vortex formation, maintaining ground clearance while enhancing rear downforce and stability at higher speeds.
Implementation Method 1
The air flowing around the motor vehicle generates turbulence at the rear of the motor vehicle when the flow separates, in which energy that has previously been applied by the drive of the vehicle is converted into useless kinetic energy of the air flowing around for propulsion.
Implementation Method 2
the at least one drive device has a transmission device, which is designed in such a way that when moving from the rest position to the working position, the side sections are first moved away from the rear apron and then the at least one air guiding device is moved backwards
Data Source
Figure 1~2
Figure 3A~3D
AI summary
A motor vehicle with a rear apron (10) whose contour can be changed by means of an air guide device (2), wherein the air guide device (2) is movable between a rest position lying against or integrated into the contour of the rear apron (10) and a working position projecting beyond the contour of the rear apron (10) by means of at least one drive device (), is characterized in that the air guide device (2) has at least one base section (22, 22') on the underside of the rear apron (10) facing the roadway and a left side section (24) as viewed in the direction of travel as well as a right side section (24') on the left side and on the right side of the rear apron (10) respectively, wherein the side sections (24, 24') are connected to the at least one base section (22, 22'),so that in the working position a U-shaped extension of the contour of the rear apron (10) directed against the direction of travel (F) is formed.