The stability of foreland types under dike breach conditions - an experimental study

Due to accelerating climate change, which entails more extreme storm conditions and exponential sea level rise, the protective function of our dikes and levees is under growing pressure. The presence of so-called forelands (e.g., beach, mudflat, and tidal marsh) are promising Nature-based Solutions to reduce the probability of dike failure and...

Venice and the lagoon: interdisciplinary design for a sustainable future: The Perfect Lagoon and The Symbiotic System

Venice is representative of the result of anthropocene acts on a vulnerable delta system. Therefore it is an excellent study case for a multidisciplinary team of TU students and tutors, to perform interdisciplinary research and design. Two visions were developed on the shared knowledge base to investigate ‘how do flood defense systems influence...

Using artificial neural networks to accelerate flowsheet optimization for downstream process development

An optimal purification process for biopharmaceutical products is important to meet strict safety regulations, and for economic benefits. To find the global optimum, it is desirable to screen the overall design space. Advanced model-based approaches enable to screen a broad range of the design-space, in contrast to traditional statistical or...

Venice and the Lagoon: Two new visions

What long ago started as a small fishing village, seeking refuge from the Romans, slowly evolved into the city of Venice that we know today. With its unique location came unique problems, most of which were related to the interplay between Venice and its lagoon. By severe measures in the past it has continued to withstand the test of time. <br/...

Comment on ‘Is ‘re-mobilisation’ nature restoration or nature destruction? A commentary’ by I. Delgado-Fernandez, R.G.D. Davidson-Arnott & P.A. Hesp

In their recently published paper, Delgado-Fernandez et al. (2019) critically review the limitations and dangers of the relatively recent shift towards dune rejuvenation management in North-western Europe. We would like to comment on the paper from the Dutch perspective.

Particle image velocimetry measurements of a thermally convective supercritical fluid

Abstract: The feasibility of particle image velocimetry (PIV) in a thermally convective supercritical fluid was investigated. Hereto a Rayleigh–Bénard convection flow was studied at pressure and temperature above their critical values. The working fluid chosen was trifluoromethane because of its experimentally accessible critical point. The...

An experimental parametric study on natural circulation BWRs stability

A parametric study on the stability performance of a prototypical natural circulation BWR is performed with the downscaled GENESIS facility. The GENESIS design is based on fluid-to-fluid modeling and includes an artificial void reactivity feedback (VRF) system for simulating the neutronic-thermal-hydraulic coupling. In this work a more...

Experimental velocity study of non-Boussinesq Rayleigh-Bénard convection

Characteristics of turbulent heat transfer in an annulus at supercritical pressure

Heat transfer to fluids at supercritical pressure is different from heat transfer at lower pressures due to strong variations of the thermophysical properties with the temperature. We present and analyze results of direct numerical simulations of heat transfer to turbulent CO2 at 8 MPa in an annulus. Periodic streamwise conditions are imposed so...

Turbulence attenuation in simultaneously heated and cooled annular flows at supercritical pressure

Heated or cooled fluids at supercritical pressure show large variations in thermophysical properties, such as the density, dynamic viscosity and molecular Prandtl number, which strongly influence turbulence characteristics. To investigate this, direct numerical simulations were performed of a turbulent flow at supercritical pressure (CO2 at 8...

Investigation of rehomogenization in the framework of nodal cross section corrections

Few-group cross sections used in nodal calculations derive from standard energy collapsing and spatial homogenization performed during preliminary lattice transport calculations, that implicitly assume an infinite array of identical fuel-assemblies. The infinite-medium neutron flux used for cross section weighting does not account for...

Analysis of the running-in phase of a passively safe thorium breeder pebble bed reactor

Natural convection driven heat transfer in fluids with strongly variable properties: A particle image velocimetry study

The High Performance Light Water Reactor (HPLWR) is one of the six innovative nuclear energy systems proposed by the Generation IV International Forum. The use of water at supercritical pressure as the coolant in the HPLWR allows a significative increase of the thermal efficiency of the power plant, a reduction in size and complexity of the...

Conceptual design of a passively safe thorium breeder pebble bed reactor