An experimental and numerical investigation of the hydrodynamics of the ducted system of a "Van Rompay Turbine": with the goal to capture energy from the current of an ocean, river, estuary or similar

Hydrokinetic energy is an environmentally friendly source of electricity and it has the advantage to be more predictable compared to other renewables. According to IRENA (2020), the capacity of converting hydrokinetic energy into electricity is expected to increase in the coming decades as many concepts are in the pipeline. One of these...

Experimental Investigation of Partial Cavitation

Cavitation is a well-known phenomenon, occurring in a wide range of applications. In most applications, cavitation is undesirable, such as turbines, pumps, ship propellers and diesel injector nozzles. Cavitation can cause material erosion, flow blockage, noise and degradation of equipment over time. The ability to predict the behavior of this...

Numerical simulation of a cavitating line vortex in a converging-diverging nozzle: using RANS and SRS methods

Tip vortex cavitation was previously identified as a source of the broadband noise emitted by ships underwater. This leads to unwanted noise and vibrations on board, which reduces passenger comfort, and increases the underwater signature of naval ships. The influence of different cavitation regimes on propellers and boundary layer transition on...

Techno-economic feasibility of Hydropower at weir-complex Driel with assessment method for low-head run-of-river powerplants

The goal of this research is to assess technical and economic feasibility of hydropower at the weir-complex of Driel. A local initiative opting to improve the environment gained interest in the idea and asked Arcadis NL for help. The weir complex at Driel lays in a key position in the Dutch river Delta and regulates the flow to the IJssel and...

Void fraction measurements in partial cavitation regimes by X-ray computed tomography

Cavitation is a complicated multiphase phenomenon, where the production of vapor cavities leads to an opaque flow. Exploring the internal structures of the cavitating flows is one of the most significant challenges in this field of study. While it is not possible to visualize the interior of the cavity with visible light, we use X-ray...

X-ray computed tomography of cavitating flow in a converging-diverging nozzle

Cavitation is a complex multiphase phenomenon, where the production of vapor bubbles leads to opaqueness of the flow. While it is nearly impossible to visualize the interior of the cavitation region with visible light, we show that with X-ray computed tomography it is possible to obtain the time-averaged void fraction distribution in an...

Direct comparison of shadowgraphy and x-ray imaging for void fraction determination

A quantitative analysis of two imaging modalities, shadowgraphy and x-ray imaging, is presented in the framework of void fraction determination. The need for this arises from the fact that shadowgraphs are sometimes utilized to quantify void fraction profiles, which is an unproven method. Time-averaged x-ray images are used to evaluate the...

Dynamics of partial cavitation in an axisymmetric converging-diverging nozzle

Partial cavitation dynamics in an axisymmetric converging-diverging nozzle are investigated experimentally. Shadowgraphy is used to visualize and analyze different cavitation regimes. These regimes are generated by changing the global static pressure and flow velocity independently. Cloud cavitation is the most interesting and complex regime,...

Reclaiming Context: Architectural Theory, Pedagogy and Practice since 1950

Context is a crucial concept in architecture, despite the frequent ambiguity around its use. It is present in many architectural thoughts and discussions, while a critical discursive reflection is absent from contemporary architectural theory and practice. Situated within this schizophrenic condition in which the notion is both absent and...

A naturally ventilated office building through solar chimneys and 'venturi' exhausts

At the Faculty of Architecture, Urbanism & Building sciences of the Technical University in Delft, research is being executed on the specific characteristics and performance of the driving ventilation components: solar chimneys and wind-induced exhausts. Along with this development the performance of a natural ventilated office building model...

A venturi-shaped roof for wind-induced natural ventilation of buildings: Wind tunnel and CFD evaluation of different design configurations

Wind tunnel experiments and Computational Fluid Dynamics (CFD) are used to analyse the flow conditions in a venturi-shaped roof, with focus on the underpressure in the narrowest roof section (contraction). This underpressure can be used to partly or completely drive the natural ventilation of the building zones. The wind tunnel experiments are...

Development of a medical Bernoulli gripper

When performing minimally invasive interventions, surgeons use grippers to grip and manipulate tissue. These grippers generally rely on their toothed profile and require pinching of the tissue for sufficient grip, entailing a risk of tissue damage. An solution should be found for this risk of damage. An alternative could be to manipulate the...

Calibration Khafagi venturi QV 303 and QV 308: Discharge characteristics for free flow and submerged flow

De invloed van cylinders in een aanstroomgoot van een Venturi-goot

Dit laboratoriumonderzoek is één van de opdrachten in het laatste jaar van het ingenieursexamen aan de afdeling Weg- en Waterbouwkunde. Het omvat enerzijds een onderzoek naar de invloed van cylinders op een waterstroom in een goot. Anderzijds is een onderzoek gedaan naar de invloed van cylinders op de stuwhoogtemeting, cq. afvoer voor een...