Convergent Nozzle for Vehicle Cab Aerodynamic Drag Reduction

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Solution Overview

Problem

Industrial vehicles face significant aerodynamic drag due to the upright windshield design, leading to increased fuel consumption and turbulence, with existing solutions either ineffective or noisy.

Innovation Solution

A convergent nozzle is integrated at the front upper corner of the vehicle cab, channeling air flow to reduce turbulence and aerodynamic drag by accelerating air to follow the cab side wall, without adding additional drag or noise, using a design where the nozzle's inner wall protrudes inwardly and the outer wall is level with the side envelope wall, forming a peripherally closed passageway with decreasing cross-section.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If an upright windshield is used in the cab, then the cargo capacity is maintained, but the aerodynamic drag increases and turbulence is generated at the upper corners

Engineering Contradiction:
Improvecargo capacityVSAvoidaerodynamic drag
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The cab is divided into functional zones with the nozzle creating a controlled airflow channel at the front upper corner, separating the main airflow path from the turbulent corner regions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nozzle acts as an intermediary device that mediates between the upward airflow along the windshield and the rearward airflow over the roof, channeling and accelerating the air to follow the cab contours smoothly

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If additional air guiding devices are added to reduce turbulence, then the aerodynamic drag is reduced, but the device complexity increases and additional drag is generated

Engineering Contradiction:
ImproveturbulenceVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The nozzle is placed locally at the front upper corner where turbulence is most acute, providing targeted airflow control only where needed rather than requiring comprehensive air guiding systems throughout the cab

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The nozzle utilizes the existing upward airflow along the windshield and converts it into a controlled rearward flow, making the airflow itself serve the aerodynamic control function without requiring additional power or complex mechanisms

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If additional air guiding devices are added to reduce turbulence, then the aerodynamic drag is reduced, but additional noise is generated

Engineering Contradiction:
Improveaerodynamic dragVSAvoidnoise
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The nozzle converts the potentially harmful upward airflow that would create turbulence into a beneficial accelerated stream that follows the cab contours smoothly, transforming a problem into a solution

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 nozzle significantly reduces aerodynamic drag and turbulence, leading to decreased fuel consumption and improved aerodynamics without generating additional drag or noise, by accelerating air to follow the cab side wall, thus enhancing the vehicle's efficiency.

Implementation Method 1

the nozzle comprising an inner wall protruding inwardly with respect to the cab side envelope wall and an outer wall substantially level with said side envelope wall so as to channel an air flow from the upright cab front section to a cab side wall at a higher velocity

Methodology Applied
Scientific EffectConvergent nozzle effect: Venturi Effect

Implementation Method 2

Thanks to the nozzle, the outgoing air is made to substantially follow the cab side wall instead of deviating from it, which limits turbulence and aerodynamic drag

Methodology Applied
Scientific EffectAerodynamic drag reduction: Drag

Data Source

PatentEP2331389B8Vehicle cab with a front air nozzle
Publication Date: 2014.02.19 RENAULT TRUCKS

AI summary

The vehicle cab (4) has a roof structure (6), an upright cab front section (7) and two side walls (8) each defining a side envelope wall extending substantially vertically. The cab incorporates at least one convergent nozzle (33) located at a front upper corner of the cab, said nozzle comprising an inner wall (20) protruding inwardly with respect to the cab side envelope wall and an outer wall substantially level with said side envelope wall so as to channel the air flow from the upright cab front section to a cab side wall at a higher velocity.