Maximizing wind farm power output with the helix approach: Experimental validation and wake analysis using tomographic particle image velocimetry

Wind farm control can play a key role in reducing the negative impact of wakes on wind turbine power production. The helix approach is a recent innovation in the field of wind farm control, which employs individual blade pitch control to induce a helical velocity profile in a wind turbine wake. This forced meandering of the wake has turned...

Predictive analytical terminal ballistics modelling of multi-layered non-metallic targets: Development, experimental validation and uncertainty quantification

Military ground vehicles require protection against ballistic threats encountered in the battlefield. Traditionally used armour steel dramatically increases the weight of a vehicle, decreasing its mobility and hampering its capability of carrying payload. The development of new material and protection concepts, namely non-metallic armours, that...

Simulating the Residual Layer Thickness in Roll-to-Plate Nanoimprinting with Tensioned Webs

Roll-to-plate nanoimprinting with flexible stamps is a fabrication method to pattern large-area substrates with micro- and nanotextures. The imprint consists of the preferred texture on top of a residual layer, of which the thickness and uniformity is critical for many applications. In this work, a numerical model is developed to predict the...

Assessment of an aircraft propeller noise model by verification and experimental validation

The need to contribute to a sustainable future of the aviation industry has spiked an interest in turboprop engines. This is due to the higher propulsive efficiency, the better take-off and landing performance on short runways, and the new developments in propeller-driven hybrid and electric aircraft. The most significant drawback is the noise...

A plucking based frequency up-converted vibration energy harvesting method: Design and model of a new frequency up-converted energy harvesting method

Vibration energy harvesting has proven to be a durable source of energy for a wide variety of applications, however not all of the positions these applications are placed at are suitable for conventional vibration energy harvesting. For some of these applications a frequency up-converted energy harvester could increase the power harvested. These...

The Structural Behaviour of Bundled Glass Columns: Finite Element Modelling and Experimental Validation

Researchers of TU Delft have been designing and engineering with columns created out of multiple glass rods that are bundled together to form a single column. These aesthetically attractive and slender columns were tested to ensure safety before implementation in the real structure: the Glass Truss Bridge located at the campus of the university....

The commotion project: Computational methods for moving and deforming objects in extreme waves

Systematic multiparameter design methodology for an ultrasonic health monitoring system for full-scale composite aircraft primary structures

The successful utilization of guided wave-based structural health monitoring (SHM) for detailed quantitative diagnostic of damage in composite aircraft primary structures depends on the excitation frequency, geometry, and positioning of the piezoelectric transducers. This study proposes a novel methodology to consistently define those parameters...

Comparison of Nested-Loop Rotors in Brushless Doubly-Fed Induction Machines

The brushless doubly-fed induction machine (DFIM) has great potential as a variable-speed generator for wind turbine applications. This special machine has a richer space-harmonic spectrum due to its special nested-loop rotor construction compared with conventional induction machines. It may result in higher iron losses, higher torque ripple and...

Finite Element Analysis and Experimental Validation of Eddy Current Losses in Permanent Magnet Machines with Fractional-Slot Concentrated Windings

Permanent-magnet machines with fractional slot concentrated windings are easy to manufacture. Their popularity therefore is steadily increasing. Without a proper design, however, the induced eddy-current losses in the solid rotor get rather high. The modeling and the prediction of eddy-current losses for these machines are thus very important...

Thermomechanical modelling of a hydrostatic machine tool spindle

Development of high precision machine tools enables the industry to continuously tighten tolerances and surface finish quality demands. Controlling the thermal state of the machine and process has become the dominant challenge for machine tool manufacturers. Defining models that predict the thermally induced deformations is an important aspect...

Free-surface flow simulations for moored and floating offshore platforms

During the development of the ComFLOW simulation method many challenges have to be tackled concerning the flow modelling and the numerical solution algorithm. Examples hereof are wave propagation, absorbing boundary conditions, fluid–solid body interaction, turbulence modeling and numerical efficiency. Some of these challenges will be discussed...

Design and thermal testing of smart composite structure for architecture applications

A composite structure consisting of a Shape Memory Polymer (SMP) matrix and three Shape Memory Alloy (SMA) strips was constructed. The SMA strips act as actuators which create forward and backward angle bends of 90 degrees of the composite structure. The function of the polymer matrix was to give the structure enough stiffness. During the...