Modular Open-Duct Wind Tunnel for Drone Aerodynamic Testing

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Solution Overview

Problem

Conventional wind tunnels are not adapted to test small air-vehicles like drones, as they cannot generate the specific turbulent wind conditions and are not safe for free-flying models, lacking the ability to measure aerodynamic performance without tethering and being modular for various scenarios.

Innovation Solution

A wind generation system with contra-rotative ventilation fans and honeycomb structures to create homogeneous turbulent flows, combined with a position sensing system and open-duct design for safe, unconstrained testing, and a modular setup for varying wind conditions and vehicle-specific testing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional wind tunnels use solid walls and ducted flow, then flow forces can be measured with transducers, but small air-vehicles cannot fly freely and may be damaged

Engineering Contradiction:
Improveaerodynamic performance measurementVSAvoidfree flight capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The wind tunnel is segmented into a test section with solid walls for force measurement and an open-duct section with no side walls for safe free flight. This segmentation allows the system to provide both measurement capability and safety for untethered drones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A modular test section acts as an intermediary between the closed-section wind tunnel and the open environment, enabling drones to fly freely while still allowing aerodynamic measurements through strategic placement of measurement equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If conventional wind tunnels generate laminar flow, then steady wind conditions are achieved, but turbulent conditions like gusts and shear cannot be simulated

Engineering Contradiction:
Improvesteady wind profileVSAvoidturbulent flow generation
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The wind tunnel transitions from static laminar flow generation to dynamic flow control, where the open-duct configuration and adjustable parameters enable real-time modification of flow characteristics to simulate various turbulent conditions including gusts, shear, and vortices.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes flow parameters by removing side walls and using adjustable diffusers and test section configurations to transform steady laminar flow into controllable turbulent flow patterns that mimic real-world flight conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conventional wind tunnels are designed for large aircraft, then flying conditions are achieved, but the facilities become extraordinarily large and non-modifiable

Engineering Contradiction:
Improveflying condition simulationVSAvoidfacility size and modifiability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The wind tunnel is divided into modular sections including a closed-section test area and an open-duct test area, allowing the facility to be configured for different vehicle sizes and test scenarios without requiring an extraordinarily large monolithic structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wind tunnel incorporates movable and adjustable components such as adjustable diffusers, removable test sections, and reconfigurable support structures, enabling the facility to be adapted for testing various drone configurations without permanent modifications.

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If test models are firmly attached to transducers, then aerodynamic forces are measured, but the models cannot perform unconstrained maneuvers

Engineering Contradiction:
Improveforce measurementVSAvoidfree maneuver capability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The measurement system is segmented into fixed transducers in the closed-section for force measurement and mobile sensing capabilities in the open-duct section, allowing drones to maneuver freely while aerodynamic forces are still captured through strategic measurement point placement.

Inventive Principle:
Principle #1Segmentation

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

Enables accurate measurement of aerodynamic performance in realistic wind conditions for small air-vehicles, allowing free flight and adaptable testing scenarios without risk of damage, with the ability to simulate various weather conditions and maneuver freely.

Implementation Method 1

each ventilation unit is composed of two contra-rotative ventilation fans mounted in series. Therefore, one reduces the generation of uncontrolled and undesired turbulences.

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

The wind generation means further comprises, in the air flow path, a first frame having a honeycomb structure and a second frame providing a plurality of homogenization chambers mounted to the wind generation units.

Methodology Applied
Scientific EffectFlow homogenization:

Data Source

PatentEP3469328B1Wind generation means and wind test facility comprising the same
Publication Date: 2021.09.29 HAUTE ECOLE DU PAYSAGE DINGIE & DARCHITECTURE DE GENEVE
  • EP3469328B1 patent drawingFigure 1A
  • EP3469328B1 patent drawingFigure 1B
  • EP3469328B1 patent drawingFigure 2

AI summary

The invention relates to a wind generation means (1) comprising at least one wind generation wall (1') comprising a plurality of wind generation units (11) provided next to each other along at least a first and a second directions so as to form the at least one wind generation wall (1'), wherein each wind generation unit (11) of said plurality of wind generation units comprises at least two ventilation units (111), each ventilation unit within the wind generation unit being individually controlled, characterized in that each wind generation unit (11) of said plurality of wind generation units comprises at least one control unit adapted to control said ventilation units (111) individually, so as to generate an arbitrary wind profile both in space and in time in an air flow path and so as to vary a generated wind physical property of said each wind generation unit along said at least first and second directions, and in that said plurality of wind generation units (11) are detachably attached to each other so that the size and shape of the said wind generation wall (1') can be varied.