Advancements in Optical Diagnostics for Experimental Aeroelasticity: Benchmarking the cylinder-foil system

Experimental aeroelasticity has been hindered by the intrusivity of measurement equipment and complexity of the experimental setups. Advancements in hardware development have been encouraging optical tracking techniques to replace cross correlation approaches in experimental aerodynamics. However, digital image correlation (DIC) is still the...

Experimental aeroelastic characterization based on integrated optical measurements

This thesis presents a novel measurement approach for aeroelastic wind tunnel testing. The key novelty of this approach is the integrated measurement of aerodynamic and structural quantities using an optical technique. The considered approach consists of combined measurements of flow tracer particles and structural markers using a Lagrangian...

Integrated Aeroelastic Measurements of the Periodic Gust Response of a Highly Flexible WIng

The aeroelastic response of a highly flexible wing to periodic gust excitation is determined experimentally. The integrated optical measurement approach that is applied provides combined measurements of the structural response of the wing and the unsteady flow field around it. The aeroelastic loads acting on the wing are derived from these...

Vertical-axis wind turbine aerodynamics

This chapter highlights the main aerodynamic phenomena and challenges of vertical-axis wind turbines. First, an introduction is provided on the VAWT history and (dis-)advantages. The basics of VAWT aerodynamics and the various rotor simplifications/representations are presented. Further, the state-of-the art aerodynamic modeling techniques,...

Unsteady Non-linear Control Surface Modelling for Aeroservoelastic Applications

In this paper, we present a data-driven method to model the unsteady non-linear response of aircraft control surfaces. This method relies on aerodynamic reduced-order models (ROM) derived from computational fluid dynamics with Reynolds averaged Navier-Stokes (CFD-RANS) analysis in the transonic domain. The ROM consists of a combination of look...

Comparative analysis of different criteria for the prediction of vortex ring state of floating offshore wind turbines

The wind condition around floating offshore wind turbines (FOWTs) can be largely different from that developed around bottom-mounted wind turbines due to the platform motions. The existing literature identifies four working state of FOWTs, one of them being the vortex ring state (VRS) which may occur as the rotor moves in its own wake. It is...

Advanced Infrared Thermography Data Analysis for Unsteady Boundary Layer Transition Detection

Advanced data processing methods for detecting unsteady boundary layer transition in periodic aerodynamic processes by means of infrared thermography measurements are presented. The thermal radiation emitted from the heated suction surface of a pitching airfoil model in subsonic flow is measured with an infrared camera. The unsteady boundary...

Aeroelastic Modelling and Design of Aeroelastically Tailored and Morphing Wings

In order to accommodate the growth in air traffic whilst reducing the impact on the environment, operational efficiency is becoming more and more important in the design of the aircraft of the future. A possible approach to increase the operational efficiency of aircraft wings is the use of aeroelastic tailoring, by taking advantage of the...

Aeroelastic Limit-Cycle Oscillations resulting from Aerodynamic Non-Linearities

Aerodynamic non-linearities, such as shock waves, boundary layer separation or boundary layer transition, may cause an amplitude limitation of the oscillations induced by the fluid flow around a structure. These aeroelastic limit-cycle oscillations (LCOs) resulting from aerodynamic non-linearities have been studied numerically in this PhD thesis...

Investigation of the unsteady flow over a wing under gust excitation

A detailed performance investigation of the gust generator built for the Open Jet Facility wind tunnel at TU Delft is summarised in this paper. The influence of various parameters such as reduced frequency, measurement location, and excitation amplitude on the generated gust profile was quantified. In addition, unsteady lift measurements were...

Three-dimensional flow and load characteristics of flexible revolving wings at low Reynolds number

This study explores the flow field and fluid-dynamic loads generated by revolving low-aspect-ratio flat plate wings undergoing a revolving motion starting from rest. Three wings with different degree of chordwise flexural stiffness (i.e., rigid, moderate flexibility and high flexibility) have been tested in order to investigate the influence of...

Aerodynamic Mechanisms of Flapping Flight

The growing need for mobile aerial platforms capable of performing reconnaissance tasks and gathering intelligence in hazardous and physically inaccessible areas has given rise to an increasing interest in the development of micro aerial vehicles (MAVs), in view of their potential capabilities of versatile and highly maneuverable flight....

Continuous-time state-space unsteady aerodynamic modelling for efficient aeroelastic load analysis

Over the years, wings have become lighter and more flexible, making them more prone to aeroelastic effects. Thus, aeroelasticity in design becomes more important. In order to determine the response of an aircraft to, for example, a gust, an unsteady aerodynamic model is required to determine the dynamic loads. The three most-commonly used...

Analyses of Aircraft Responses to Atmospheric Turbulence

The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate mathematical model is required. Two classical models...