Showing papers in "Nuclear Engineering and Design in 2008"

TL;DR: In this article, three-dimensional numerical analysis was performed to investigate heat transfer and pressure drop characteristics of supercritical CO2 flow in new Printed Circuit Heat Exchanger (PCHE) model using commercial CFD code, Fluent 6.3.

TL;DR: A generalized inhomogeneous multiple size group (MUSIG) model based on the Eulerian modeling framework was developed in close cooperation of ANSYS-CFX and Forschungszentrum Dresden-Rossendorf and implemented into the CFD code CFX as discussed by the authors.

TL;DR: In this article, the authors present multiphase flow models for the description of mono-and polydisperse bubbly flows in the Eulerian framework of multi-phase flow modeling in ANSYS CFX.

TL;DR: In this paper, the full velocity field using particle image velocimetry technique (PIV) in a conjunction with matched refractive index fluid with the pebbles to achieve optical access is presented.

TL;DR: In this paper, the authors proposed dimensionless parameters for the analysis of stability in heated channels with supercritical fluids, based on the classical phase change and sub-cooling numbers adopted in the case of boiling channels, proposing a novel formulation making use of fluid properties at the pseudocritical temperature as a function of pressure.

TL;DR: In this paper, a numerical model has been developed to predict early-age cracking for massive concrete structures, taking into account creep at early age is essential if one wants to predict quantitatively the induced stresses.

TL;DR: In this article, the most promising technologies for the compact recuperator were investigated within the Work Package 2 “Recuperator” of the High Temperature Reactor-E European program.

TL;DR: In this paper, a new prediction model for frictional pressure drop of two-phase flow in pipes is proposed, which includes a new definition of the Reynolds number and the friction factor.

TL;DR: A software tool is presented for automated APET generation using the concept of dynamic event trees that determines the branching times from a severe accident analysis code based on user specified criteria for branching.

TL;DR: In this paper, a simple explicit correlation was developed based on these non-dimensional numbers for the prediction of entrainment fraction in upward co-current air-water annular flow covering wide ranges of pressure and flow conditions.

TL;DR: In this paper, the stability threshold of a natural circulation loop with supercritical fluid is not confined to the near-peak region of the (steady state) flow-power curve.

TL;DR: In this paper, a study of the variation in the radial direction in the porosity of annular packed beds is presented, based on a comparison between the predictions by a number of empirical correlations found in literature and the porosities obtained from physical experiments and the analysis of numerically generated packed beds.

TL;DR: Azzopardi et al. as mentioned in this paper measured liquid film thickness by two flush mounted ring-shaped conductance probes located 38.1mm apart and estimated disturbance wave velocity, frequency, amplitude and wavelength by following the statistical analysis methods.

TL;DR: In this article, two horizontal channels with rectangular cross-section were built at Forschungszentrum Dresden-Rossendorf (FZD) for the investigation of air/water co-current flows, especially the slug behaviour, at atmospheric pressure and room temperature.

TL;DR: In this article, the effect of low frequency oscillations on flow rate and pressure drop in a vertical tube has been studied experimentally in the presence of a 1.75m-long vertical tube of inner diameter 0.016m.

TL;DR: In this paper, the authors examined the effects of using noble gases and binary mixtures as reactor coolants and direct closed Brayton cycle (CBC) working fluids on the performance of terrestrial nuclear power plants and the size of the turbo-machines.

TL;DR: In this paper, the authors investigated the seismic response of liquid storage steel tanks isolated with variable friction pendulum system (VFPS) under normal component of six recorded near-fault ground motions.

TL;DR: In this paper, a convective flow boiling of refrigerant R-113 in a vertical annular channel has been simulated by a CFD (Computational Fluid Dynamics) code CFX.

TL;DR: In this article, the thermal-hydraulic stability of a uniformly heated channel at supercritical water pressure has been investigated to help understand the system instability phenomena which may occur in super-critical water nuclear reactors (SCWRs).

TL;DR: In this article, the stochastic particle tracking model in Fluent 62 is modified to include a better treatment of particle-turbulence interactions close to walls where anisotropic effects are significant.

TL;DR: In this article, the authors proposed a method for decontaminating graphite from radionuclides using steam reforming, which is an alternative to pure thermal treatment in an inert atmosphere, as was first demonstrated in the HTR-N/N1 project.

TL;DR: In this paper, the authors investigated local condensation heat transfer coefficients in the presence of a non-condensable gas inside a vertical tube and found that the local heat transfer coefficient increased as the inlet steam flow rate increased and inlet nitrogen gas mass fraction decreased.

TL;DR: In this article, the simulation of turbulent transport for the gas through the gaps of the spherical fuel elements (fuel pebbles) was performed using the large eddy simulation, which would help in understanding the highly three-dimensional, complex flow phenomena caused by flow curvature in the pebble bed.

TL;DR: The German containment code system COCOSYS as mentioned in this paper is composed of three main modules, which are separate executable files, covering thermal hydraulics including hydrogen combustion, fission products mainly aerosols and iodine behaviour, and corium behaviour with molten corium concrete interaction.

TL;DR: In this paper, a lumped parameter mathematical model of the helical coiled once-through steam generator of the 10 MW high-temperature gas-cooled reactor (HTR-10) is developed based upon the fundamental conservation of fluid mass, energy and momentum.

TL;DR: In this paper, the authors focus on the modeling and numerical simulation with the NEPTUNE_CFD code of cavitation phenomena and boiling bubbly flows and propose a modification of the classical nucleate boiling model to overcome the strong model sensitivity with respect to near wall grid refinement.

TL;DR: The Rossendorf Coolant Mixing Model (ROCOM) as mentioned in this paper is a test facility for the investigation of coolant mixing in the primary circuit of pressurized water reactors.

TL;DR: The megawatt pilot experiment (MEGAPIE) has been launched by six European institutions (PSI, FZK, CEA, SCK-CEN, ENEA and CNRS), JAEA (Japan), DOE (US) and KAERI (Korea) with the aim to carry out an experiment, in the SINQ target location at PSI (Switzerland), to demonstrate the safe operation of a liquid metal (lead-bismuth eutectic, LBE) spallation target hit by a ∼1

TL;DR: The BEMUSE Phase 3 benchmark as discussed by the authors was the first one to perform uncertainty and sensitivity analysis of thermal-hydraulic codes used for the calculation of LOFT L2-5 experiment, which simulated a Large Break Loss-of-Coolant-Accident (LB-LOCA).

TL;DR: In this article, a theoretical model of fracture toughness was proposed, according to which the ductile fracture toughness is obtained from the SP energy, the plastic deformation and the experimental fractography.