Lift-Induced Wake Re-Energization for a VAWT-Based Multi-Rotor System

In response to the urgent need for renewable energy amidst the escalating impacts of global warming, this study delves into the forefront of wind energy research, particularly focusing on the innovative Multi-Rotor System (MRS). The MRS concept offers a promising departure from the prevailing trend of scaling up traditional turbines, instead...

Wall Interference Assessment of Isolated Fixed-Pitch Propeller Tests

The need to reduce greenhouse gas emissions is emergent throughout every industrial sector worldwide. For aviation, this has opened a market gap for small scale electric aircraft configurations (e-V/STOL). These configurations are very diverse and they are classified based on how lift is obtained. However, their flight...

Air–water properties of unsteady breaking bores part 1: Novel Eulerian and Lagrangian velocity measurements using intrusive and non-intrusive techniques

Transient motion, turbulence and bubble dynamics make any velocity quantification extremely difficult in unsteady gas–liquid flows. In the present study, novel Eulerian and Lagrangian techniques of velocimetry were developed, using both intrusive and non-intrusive measurements. The selected unsteady gas–liquid flow was a breaking bore,...

On the Taylor column driven motion of a buoyant sphere in a free-surface vortex core: An experimental study

The added drag on a buoyant body traveling in a solid-body rotation flow has been rigorously studied over the last century with G.I. Taylor being the first one to describe it in 1922, a hundred years ago. A recent publication by Duinmeijer (2021) investigated the capacity of free-surface vortices to transport solids as a practical application to...

Assessing the Effectiveness of the IJmuiden Salt Screen Design for Nonuniform Selective Withdrawal by Physical and Numerical Modeling

Salt water intrusion through the New Sea Lock of IJmuiden, Netherlands requires mitigation to ensure availability of enough fresh water further inland. For this purpose, a salt screen has been proposed for selective withdrawal of salt water from the Noordzeekanaal in the vicinity of the lock complex. Formulas to assess the withdrawal rate of...

Path instabilities of a freely rising or falling sphere

Path instabilities of a sphere rising or falling in a quiescent Newtonian fluid have been studied experimentally. The rich palette of possible instabilities is dependent upon two dimensionless quantities, namely the Galileo number (Ga) and the particle/fluid mass density ratio (ρ¯). In recent literature, several (Ga,ρ¯) regime maps have been...

Nonspherical particles in a pseudo-2D fluidized bed: Experimental study

Fluidization is widely used in industries and has been extensively studied, both experimentally and theoretically, in the past. However, most of these studies focus on spherical particles while in practice granules are rarely spherical. Particle shape can have a significant effect on fluidization characteristics. It is therefore important to...

Measurement of particle dynamics in a coherent acoustic field

A variety of forces can be used to separate fine particles from water in industrial processes. A coherent standing acoustic field can apply a pressure difference across a small particle such that the particle is forced to nodes or anti-nodes in the field depending of particle/liquid properties. The motion of an individual particle is the result...

Moving liquid droplets with inertia: Experiment, simulation, and theory

This thesis is a work on a contact line instability at a finite Reynolds number, 0 < Re < O(100). This problem corresponds to an immersion droplet applied in a liquid- immersion lithography machine. We perform extensive works to understand this instability problem by means of experimental, numerical, and theoretical ways. First, in order to...

Particle Tracking in a Shallow Mixing Layer: A Fluid Dynamics Laboratory in the Field

At locations where two natural streams of different velocity come together, a mixing layer develops. In this free shear flow, the velocity difference between the two streams is gradually reduced through the exchange of lateral momentum. This involves different forms of turbulent phenomena. If the width of the flow domain is large compared to the...

Particle tracking velocimetry in ondiep-water menglagen

In onderhavige studie is de meettechniek "Particle Tracking Velocimetry" (PTV) toegepast ten behoeve van het onderzoek naar ondiepe waterstromingen. Het doel van het onderzoek was de meettechniek beschikbaar te krijgen voor studies aan ondiep-waterstromingen en de geschiktheid van de methode voor het meten van grootschalige structuren aan te...