Transition to turbulence behind a traveling plate

In our experiment a vortical flow behind a traveling plate turns into turbulence. By exactly repeating this experiment 42 times with a robot, we study the statistics of this transition. In each realization the fate of the flow is followed over 1.7 s when the plate travels with a constant velocity. It suddenly turns turbulent at a scaled...

Drag Force on a Starting Plate Scales with the Square Root of Acceleration

We report results on the instantaneous drag force on plates that are accelerated in a direction normal to the plate surface, which show that this force scales with the square root of the acceleration. This is associated with the generation and advection of vorticity at the plate surface. A new scaling law is presented for the drag force on...

Investigation on the drag force and flow field of an accelerating plate

We present results on the instantaneous drag force acting on a rectangular plate that accelerates in a direction normal to the plate surface. Conventionally the drag force on an accelerating object is divided into a steady state term and an added mass term, which can both be time-dependent. However, for prolonged accelerations this theory...

Large-scale structures of scalar and velocity in a turbulent jet flow

We study the relation between large-scale structures in the concentration field with those in the velocity field in a dye-seeded turbulent jet. The scalar concentration in a plane is measured using laser-induced fluorescence. Uniform concentration zones of an advected scalar are indentified using cluster analysis. We simultaneously measure...

The organization of scalar mixing by coherent structures: An experimental study

Turbulent scalar mixing is prominent in all sorts of situations, being it in air pollution or making tea. However, this does not often lead to a homogeneously mixed fluid, but rather leads to regions of higher concentrations next to regions with significantly lower concentrations. This can be characterized by dividing the concentration field in...

A circular business ecosystem approach towards achieving high value use of salvaged building materials in the Dutch built environment: The case of Dutch demolition contractors

Like Industrial Ecology research makes use of the analogy between closed-loop systems in nature and material flows in the economy, business ecosystem literature uses the analogy of ecosystems to explain cross-industry cooperative behavior. Regarding the Circular Economy transition, a circular business ecosystem can be defined as ‘a set of actors...

Sea, Sand and Sustainability: How can the beach pavilions at Scheveningen align themselves with The Hague’s Climate Agreement?

We were commissioned to support the beach pavilions at Scheveningen in aligning themselves with the climate goals of the Haags Klimaatpact. We decided to focus on collaborative measures that they could take to make better use of energy, materials and water. We used the perspective we have developed in the last year from Industrial Ecology to...

Towards a design for an improved drinking water supply system on Bonaire, St Eustatius and Saba

In 2008, the author has conducted a research study on behalf of the Caribbean Water Association on the consequences of the constitutional change of the Netherlands Antilles for the drinking water supply on Bonaire, St Eustatius and Saba (BES). This research study formed the basis for further research in the form of this MSc. thesis. Being the...

Minimum design requirements for domestic rainwater-harvesting systems on small volcanic islands in the Eastern Caribbean to prevent related water quality and quantity issues

Rainwater harvesting is the primary source of fresh water on the majority of isolated and volcanic islands in the Eastern Caribbean island chain that lack reliable sources fresh water. Recent research studies have determined that the microbiological quality of rainwater in cistern systems is generally unstable and can lead to serious health...