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This paper focuses on the application of CFD to turbocharger compressor characteristics predictions over a range of speeds between 100,000 and 200,000RPM, and concentrating around the peak performance at 160,000RPM. A production turbocharger compressor which is widely used in the small-to-medium size automotive sector is studied. A methodical approach is taken to compare computation versus rig measurements, which represents an idealised installation. Benchmarking under the idealised rig conditions then gives a degree of confidence to apply the same prediction method to the device under real...
A computational fluid dynamics (CFD) model was developed to investigate the natural ventilation of a climatic livestock building under different wind incidences (WIs) for three different inlet opening areas. A ½ scale experimental duopitch building was employed to validate, both qualitatively and quantitatively, the CFD predictions of airflow distribution. To improve the applicability of CFD to building design, a thermal comfort index called the “minimum comfort temperature” was used in this study. Results showed that ventilation rates were not at their highest when wind was blowing normal to...
This paper presents the use of large eddy simulations for calculating turbulent flows in the nuclear field. It focuses on the knowledge of temperature or pressure fluctuations, required to address issues such as thermal fatigue or vibrations. The different subgrid models used and their integration in the commercial CFD software STAR-CD are described. A representative set of applications performed – validation and industrial cases – in the last 15 years is presented. The flow configurations are mainly tee junctions, but also cross-flows over obstacles and shear layers, with water, sodium and...
Accurate simulation of subcooled boiling flow is essential for the operation and safety of nuclear power plants (NPP). In recent years, the use of computational fluid dynamics (CFD) codes has been extended to the analysis of multi-dimensional two-phase flow for the NPP. Among the applications of CFD code for the NPP analysis, the first target was selected as a mechanistic prediction of DNB (Departure from Nucleate Boiling) in PWR (Bestion et al, 2006). In DNB-type CHF (Critical Heat Flux), the expected flow regime is bubbly or churn turbulent flow in the high mass flux and high heat flux...
In order to demonstrate the potential of magnetic refrigeration which can provide cooling effects without affecting the environment, an experimental setup was built, in which a rotating regenerative gadolinium beds of 350 g were used. Water was used as a heat transfer fluid, and a magnetic field of 1.5 T was applied using permanent magnets. With this setup, the influence of the heat transfer fluid, the temperature drop was studied systematically. The analytical solution for entropy change as a function of enthalpy and temperature were obtained in MATLAB and compared with the experimental...
In the computational fluid dynamics (CFD) analysis of spray dryers, the Euler-Lagrange model is used to compute the motions of the spray droplets and the heat and mass transfers between the droplets and the air stream. Such calculations are performed for hundreds to tens of thousands of droplets to represent the spray in the dryer. One limiting factor in drying mass transfer is the internal diffusion of water moisture inside partially dried particles. In order to model this internal diffusion of water moisture, each particle is represented by a series of concentric spherical shells. A one-...
Background and Purpose —The ability to discriminate between ruptured and unruptured cerebral aneurysms on a morphological basis may be useful in clinical risk stratification. The objective was to evaluate the importance of inflow-angle (IA), the angle separating parent vessel and aneurysm dome main axes. Methods—IA, maximal dimension, height–width ratio, and dome–neck aspect ratio were evaluated in sidewall-type aneurysms with respect to rupture status in a cohort of 116 aneurysms in 102 patients. Computational fluid dynamic analysis was performed in an idealized model with variational...
Measurements have been done in order to obtain information concerning the effect of EGR for the smoke and NO x emissions of a heavy-duty diesel engine. Measured smoke number and NO x emissions are explained using detailed chemical kinetic calculations and CFD simulations. The local conditions in the research engine are analyzed by creating equivalence ratio - temperature (Phi-T) maps and analyzing the CFD results within these maps. The study uses different amount of EGR and the standard EN590 diesel fuel. The detailed chemical kinetic calculations take into account the different EGR rates...
In order to assess the accuracy and validity of subchannel, system, and computational fluid dynamics codes, the Paul Scherrer Institut has participated in the OECD/NRC PSBT benchmark with the thermal-hydraulic system code TRACE5.0 developed by US NRC, the subchannel code FLICA4 developed by CEA, and the computational fluid dynamic code STAR-CD developed by CD-adapco. The PSBT benchmark consists of a series of void distribution exercises and departure from nucleate boiling exercises. The results reveal that the prediction by the subchannel code FLICA4 agrees with the experimental data...

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