33,820 research outputs found
ICANOE and OPERA experiments at the LNGS/CNGS
We discuss two experiments ICANOE and OPERA that have been proposed within
the context of long-baseline and atmospheric neutrino experiments in Europe.
The joint ICANOE/OPERA program aims at further improving our understanding of
the effect seen in atmospheric neutrinos. This program is based on (1) a
continuation of the observation of atmospheric neutrinos with the improved
technique of ICANOE/ICARUS (2) a sensitive numu->nue and numu->nutau appearance
program with the accelerator neutrinos coming from CERN (CNGS) from a distance
of 730 km.Comment: 8 pages; Invited talk at the XIX International Conference on Neutrino
Physics and Astrophysics (Neutrino 2000), Sudbury, Canada, June 16-21, 2000;
new version fix typo
Low-gravity fluid physics: A program overview
An overview is presented of the microgravity fluid physics program at Lewis Research Center. One of the main reasons for conducting low gravity research in fluid physics is to study phenomena such as surface tension, interfacial contact angles, and diffusion independent of such gravitationally induced effects as buoyant convection. Fluid physics is at the heart of many space-based technologies including power systems, thermal control systems, and life support systems. Fundamental understanding of fluid physics is a key ingredient to successful space systems design. In addition to describing ground-based and space-based low-gravity facilities, selected experiments are presented which highlight Lewis work in fluid physics. These experiments can be categorized into five theme areas which summarize the work being conducted at Lewis for OSSA: (1) isothermal/iso-solutal capillary phenomena; (2) capillary phenomena with thermal/solutal gradients; (3) thermal-solutal convection; (4) first- and second-order phase transitions in a static fluid; and (5) multiphase flow
Underground operation of the ICARUS T600 LAr-TPC: first results
Open questions are still present in fundamental Physics and Cosmology, like
the nature of Dark Matter, the matter-antimatter asymmetry and the validity of
the particle interaction Standard Model. Addressing these questions requires a
new generation of massive particle detectors exploring the subatomic and
astrophysical worlds. ICARUS T600 is the first large mass (760 ton) example of
a novel detector generation able to combine the imaging capabilities of the old
famous "bubble chamber" with an excellent energy measurement in huge electronic
detectors. ICARUS T600 now operates at the Gran Sasso underground laboratory,
studying cosmic rays, neutrino oscillation and proton decay. Physical
potentialities of this novel telescope are presented through few examples of
neutrino interactions reconstructed with unprecedented details. Detector design
and early operation are also reported.Comment: 14 pages, 8 figures, 2 tables. Submitted to Jins
A Library for Wall-Modelled Large-Eddy Simulation Based on OpenFOAM Technology
This work presents a feature-rich open-source library for wall-modelled
large-eddy simulation (WMLES), which is a turbulence modelling approach that
reduces the computational cost of traditional (wall-resolved) LES by
introducing special treatment of the inner region of turbulent boundary layers
(TBLs). The library is based on OpenFOAM and enhances the general-purpose LES
solvers provided by this software with state-of-the-art wall modelling
capability. In particular, the included wall models belong to the class of
wall-stress models that account for the under-resolved turbulent structures by
predicting and enforcing the correct local value of the wall shear stress. A
review of this approach is given, followed by a detailed description of the
library, discussing its functionality and extensible design. The included
wall-stress models are presented, based on both algebraic and ordinary
differential equations. To demonstrate the capabilities of the library, it was
used for WMLES of turbulent channel flow and the flow over a backward-facing
step (BFS). For each flow, a systematic simulation campaign was performed, in
order to find a combination of numerical schemes, grid resolution and wall
model type that would yield a good predictive accuracy for both the mean
velocity field in the outer layer of the TBLs and the mean wall shear stress.
The best result was achieved using a mildly dissipative second-order accurate
scheme for the convective fluxes applied on an isotropic grid with 27000 cells
per -cube, where is the thickness of the TBL or the
half-height of the channel. An algebraic model based on Spalding's law of the
wall was found to perform well for both flows. On the other hand, the tested
more complicated models, which incorporate the pressure gradient in the wall
shear stress prediction, led to less accurate results
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