Towards a Better Understanding of Attitude Oscillations Experienced by Quadcopters In Axial Descent

This study aims to quantify the aerodynamic behaviour of fixed pitch rotors with a diameter of 12.7 cm in axial descent, and its contribution to the attitude oscillations found for quadcopters under similar flight conditions. Wind tunnel tests are performed with an isolated rotor, as well as a complete quadcopter mounted inside a gimbal that...

Development of an Active Aeroelastic Parametric Wing Apparatus

This paper presents the development and initial characterization of an active, para- metric wing section with aileron and spoiler control surfaces. This wing section is intended to replace the currently used passive wing section setup and facilitate research in active con- trol techniques of aeroelastic phenomena such as flutter, gust load...

On the combined flow and structural measurements via robotic volumetric PTV

This study describes a novel measurement approach for combined flow and structural measurements in wind tunnels using robotic volumetric particle tracking velocimetry (PTV). The measurement approach is based on the application of a particle tracking algorithm on images including flow or structure tracers, where the latter are implemented by...

Proof of concept study for fuselage boundary layer ingesting propulsion

Key results from the EU H2020 project CENTRELINE are presented. The research activities undertaken to demonstrate the proof of concept (technology readiness level-TRL 3) for the so-called propulsive fuselage concept (PFC) for fuselage wake-filling propulsion integration are discussed. The technology application case in the wide-body market...

Aircraft induced sound propagation in the urban context: A scale model wind study towards urban noise abatement using a self-build wind tunnel

Exposure to excessive community noise has become a large environmental health concern. Noise pollution continues to increase while it is accompanied by direct, as well as cumulative adverse health effects. In addition, prolonged exposure to excessive noise levels also has a negative economic impact. The incorporation of numerical tools in the...

Accurate position control of a flapping-wing robot enabling free-flight flow visualisation in a wind tunnel

Flow visualisations are essential to better understand the unsteady aerodynamics of flapping wing flight. The issues inherent to animal experiments, such as poor controllability and unnatural flapping when tethered, can be avoided by using robotic flyers that promise for a more systematic and repeatable methodology. Here, we present a new...

Fog Water Collection Efficiency: The Influence of Collector Geometry

Fog harvesting is a sustainable drinking water solution for arid climates. Previous studies have developed an analytical model to predict the fog water collection efficiency as a product of aerodynamic and deposition efficiency as independent factors. In this study, we tested the assumption that deposition efficiency stays unchanged when the...

A comparison of downwind sail coefficients from tests in different wind tunnels

Wind turbine aerodynamics in yaw: Unravelling the measured rotor wake

Rotational Augmentation Disparities in the MEXICO and UAE Phase VI Experiments

Wind turbine structures and components suffer excessive loads and premature failures when key aerodynamic phenomena are not well characterized, fail to be understood, or are inaccurately predicted. Turbine blade rotational augmentation remains incompletely characterized and understood, thus limiting robust prediction for design. Pertinent...

Experimental investigation of re-entry aerodynamic phenomena - Development of non-intrusive ?ow diagnostics in a Ludwieg tube

To further improve the design of hypersonic vehicles so that fully reusable systems become a reality, the detailed understanding of the ?ow ?eld that the vehicle generates is of paramount importance. The thesis deals with the aspects of experimental ?ow research which includes also the ?ow facility and the measurement techniques. First a...

Control of suction distributions on Boundary layer suction systems for automotive wind tunnels

Wind tunnels are used to study airflows around objects like cars, airplanes and ice-skaters. This is done, simulating the real world, by blowing an airflow over a fixed body. In the real situation an object moves through the air, while in a wind tunnel it is the air that is moving. So a wind tunnel needs to generate an airflow. In this airflow,...

Status of Wake Vortex Alleviation in the Framework of European Collaboration: Validation Using Tests and CFD Results

This document provides a synthesis of recent research studies that have been conducted in the last decade within several European projects from the 5th and 6th Framework Programmes. All these studies aimed at a better characterization of aircraft wake vortices and then at their subsequent control. In the latter case, the goal is to minimize the...

Uncertainty in wind pressure coefficients for low-rise buildings

This paper reports on an analysis of the uncertainty in wind pressure (difference) coefficients, which are assessed on the basis of generic knowledge and experimental data rather than with a specific (wind tunnel) experiment. The analysis is carried out on time averaged pressure coefficients in a specific case, concerning a low-rise building in...