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To allow the detailed analysis of the two-phase coolant flow and heat transfer phenomena in a Boiling Water Reactor fuel bundle the CFD-BWR model is being developed for use with the commercial code STAR-CD which provides general two-phase flow modeling capabilities. The paper reviews the key boiling phenomenological models, describes the overall strategy adopted for the combined CFD-BWR and STAR-CD boiling models validation and presents results of a set of experiment analyses focused on the validation of specific models implemented in the code. The location of vapor generation onset, axial...
Verifying numerical predictions with experimental data is an important aspect of any modeling studies. In the case of the lung, the absence of direct in vivo flow measurements makes such verification almost impossible. We performed computational fluid dynamics (CFD) simulations in a 3D scaled-up model of an alveolated bend with rigid walls that incorporated essential geometrical characteristics of human alveolar structures and compared numerical predictions with experimental flow measurements made in the same model by particle image velocimetry (PIV). Flow in both models was representative of...
This paper presents results of a research project within Heerema Marine Contractors to determine added mass and damping coefficients of suction piles using CFD. Analyses have been performed for suction piles which are fully closed and with open hatches. The results are compared with model tests presented at the OMAE by Ireland et al. (2007) and Roe et al. (2008). Two modeling approaches have been used. The first approach is simulating a forced oscillation by oscillating the flow around a fixed body. The second approach is by using a Dynamic Fluid Body Interaction (DFBI) model simulating a...
FORCE Technology, Grontmij│Carl Bro and Rolls Royce in Denmark are involved in a joint project under DCMT (Danish Centre for Maritime Technology). The goal of the project is to test and demonstrate the capabilities of RANS in connection with flow simulations for different rudder and propeller configurations. Focus is on a complete CFD model for hull, propeller and appendages, which can account for the mutual interaction between the components when the flow field is calculated. In RANS, propellers can be modeled by body-forces as in , but in the present work the real propeller geometry is...
A new meshing methodology for faster simulation of a Body-In-White dipping process
Simulation of complete body-in-white dipping processes demands a special mesh that is able to model complete geometrical features with the least surface cell count on the body, while representing the sheet metal thickness and ensuring mesh continuity among approximately 400 Body-in-White (BIW) components. Currently employed semi-automatic approaches for producing such meshes are often time intensive and involve huge manual effort. Therefore, a new meshing methodology is developed in STAR-CCM+ with the help of Java automation API and pipeline meshing technology which has automated the surface...
Discrete Element Methods in STAR-CCM+
Dense granular systems are very common natural phenomenon. Sand, pebbles, soil, seeds and powders are all examples of granular flows. Whilst the modeling of granular flows with Eulerian methodology had some success, there is still no known constitutive relation that governs dense granular flow based on grain-scale physics. Recent architecture advances and access to CPU power enables to use granular flow modeling based on Discrete Element Model (DEM) both, for dry granular flows and for flows of particles coupled with traditional CFD solvers. This presentation introduces the DEM simulation...
In the past, testing of lifeboat design has been carried out solely by experimental means.However, due to the large number of factors which influence the loads on the lifeboat. structure and its occupants, optimization studies by experimental means have become both time-consuming and expensive. In addition, many eects cannot be studied at laboratory scale due to the inability to match all similarity requirements. Recent advances in computational fluid dynamics (CFD) have made it possible to analyze the lifeboats performance under realistic conditions. By not being dependent on a physical...
Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less...
Several experiments have already reported the existence of flow oscillations in a tight lattice bare rod-bundle. This in-turn results in temperature oscillations, when heat transfer is also involved. Consequently, assessment of flow oscillations plays an important role in the design of future innovative reactor systems as proposed by the Generation IV International Forum. Literature review reveals that such flow oscillations have recently numerically been analyzed using Unsteady Reynolds Averaged Navier-Stokes (URANS) and Large Eddy Simulation (LES) techniques. The objective is to assess...
Distributions in the concentration of reactant species in a PEMFC can cause distributions in local current density, temperature, and water content over the area of a PEMFC. These distributions can lead to effects such as flooding and MEA dehydration thus causing stresses in different regions of the fuel cell. Changing flow-field configurations and channel characteristics have been shown to also affect the cell performance and uniformity indistributions. This work investigates how performance and distributions in a baseline laboratory cell prepared by a precise machining method compared with...

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