scholarly journals Geother evaluation and improvement: A progress report including test cases for two-dimensional BWIP (Basalt Waste Isolation Project) analysis

1988 ◽  
Author(s):  
S.H. Bian ◽  
M.J. Budden ◽  
C.L. Bartley ◽  
S.C. Yung
Keyword(s):  
Progress Report ◽  
Test Cases ◽  
Two Dimensional ◽  
Project Analysis

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

scholarly journals Two-Dimensional Evaluation of ATHAM-Fluidity, a Nonhydrostatic Atmospheric Model Using Mixed Continuous/Discontinuous Finite Elements and Anisotropic Grid Optimization

2016 ◽  
Vol 144 (11) ◽  
pp. 4349-4372 ◽  
Author(s):  
Julien Savre ◽  
James Percival ◽  
Michael Herzog ◽  
Chris Pain
Keyword(s):  
Optimization Algorithm ◽  
Large Scale ◽  
Atmospheric Model ◽  
Computational Time ◽  
Limited Area ◽  
Test Cases ◽  
Two Dimensional ◽  
Element Discretization ◽  
Wide Range ◽  
Grid Optimization

Abstract This paper presents the first attempt to apply the compressible nonhydrostatic Active Tracer High-Resolution Atmospheric Model–Fluidity (ATHAM-Fluidity) solver to a series of idealized atmospheric test cases. ATHAM-Fluidity uses a hybrid finite-element discretization where pressure is solved on a continuous second-order grid while momentum and scalars are computed on a first-order discontinuous grid (also known as ). ATHAM-Fluidity operates on two- and three-dimensional unstructured meshes, using triangular or tetrahedral elements, respectively, with the possibility to employ an anisotropic mesh optimization algorithm for automatic grid refinement and coarsening during run time. The solver is evaluated using two-dimensional-only dry idealized test cases covering a wide range of atmospheric applications. The first three cases, representative of atmospheric convection, reveal the ability of ATHAM-Fluidity to accurately simulate the evolution of large-scale flow features in neutral atmospheres at rest. Grid convergence without adaptivity as well as the performances of the Hermite–Weighted Essentially Nonoscillatory (Hermite-WENO) slope limiter are discussed. These cases are also used to test the grid optimization algorithm implemented in ATHAM-Fluidity. Adaptivity can result in up to a sixfold decrease in computational time and a fivefold decrease in total element number for the same finest resolution. However, substantial discrepancies are found between the uniform and adapted grid results, thus suggesting the necessity to improve the reliability of the approach. In the last three cases, corresponding to atmospheric gravity waves with and without orography, the model ability to capture the amplitude and propagation of weak stationary waves is demonstrated. This work constitutes the first step toward the development of a new comprehensive limited area atmospheric model.

A New Visualization Method for Harmonic Unsteady Flows in Turbomachinery

2016 ◽  
Author(s):  
Tobias Gezork ◽  
Paul Petrie-Repar ◽  
Torsten Fransson
Keyword(s):  
Unsteady Flow ◽  
Group Velocity ◽  
Forced Response ◽  
Test Cases ◽  
Visualization Method ◽  
Two Dimensional ◽  
Flat Plates ◽  
Linear Cascade ◽  
Field Lines ◽  
Turbomachinery Design

Understanding unsteady flow processes is key in the analysis of challenging problems in turbomachinery design such as flutter and forced response. In this paper a new visualization method for harmonic unsteady flow is presented. The method illustrates the direction in which unsteady waves are traveling and transporting energy by the direct visualization of the propagating pressure waves in terms of field lines constructed from the wave group velocity. The group velocity is calculated from the unsteady flow solution by assuming that the local unsteady pressure perturbation of interest can be represented by a single harmonic unsteady wave. The applicability of the method is demonstrated for three test cases including a linear cascade of two-dimensional flat plates and a linear cascade of two-dimensional compressor blade profiles.

A new CUDA-based GPU implementation of the two-dimensional Athena code

2013 ◽  
Vol 61 (1) ◽  
pp. 239-250
Author(s):  
A. Wasiljew ◽  
K. Murawski
Keyword(s):  
Dimensional Space ◽  
Test Cases ◽  
Double Precision ◽  
Central Processor ◽  
Two Dimensional ◽  
Central Processor Unit ◽  
Hardware Configuration ◽  
Cuda Architecture ◽  
Processor Unit ◽  
Gpu Implementation

Abstract We present a new version of the Athena code, which solves magnetohydrodynamic equations in two-dimensional space. This new implementation, which we have named Athena-GPU, uses CUDA architecture to allow the code execution on Graphical Processor Unit (GPU). The Athena-GPU code is an unofficial, modified version of the Athena code which was originally designed for Central Processor Unit (CPU) architecture. We perform numerical tests based on the original Athena-CPU code and its GPU counterpart to make a performance analysis, which includes execution time, precision differences and accuracy. We narrowed our tests and analysis only to double precision floating point operations and two-dimensional test cases. Our comparison shows that results are similar for both two versions of the code, which confirms correctness of our CUDA-based implementation. Our tests reveal that the Athena-GPU code can be 2 to 15-times faster than the Athena-CPU code, depending on test cases, the size of a problem and hardware configuration.

scholarly journals Two Dimensional Analysis and Optimization of Hybrid MDCD-TENO Schemes

2021 ◽  
Vol 90 (1) ◽  
Author(s):  
Raynold Tan ◽  
Andrew Ooi
Keyword(s):  
Dimensional Analysis ◽  
Spectral Properties ◽  
Linear Part ◽  
Grid Size ◽  
Shock Capturing ◽  
Test Cases ◽  
Two Dimensional ◽  
Analysis Framework ◽  
Hybrid Scheme ◽  
Linearized Euler Equations

AbstractIn this article, a quasi-linear semi-discrete analysis of shock capturing schemes in two dimensional wavenumber space is proposed. Using the dispersion relation of the two dimensional advection and linearized Euler equations, the spectral properties of a spatial scheme can be quantified in two dimensional wavenumber space. A hybrid scheme (HYB-MDCD-TENO6) which combines the merits of the minimum dispersion and controllable dissipation (MDCD) scheme with the targeted essentially non-oscillatory (TENO) scheme was developed and tested. Using the two dimensional analysis framework, the scheme was spectrally optimized in such a way that the linear part of the scheme can be separately optimized for its dispersion and dissipation properties. In order to compare its performance against existing schemes, the proposed scheme as well as the baseline schemes were tested against a series of benchmark test cases. It was found that the HYB-MDCD-TENO6 scheme provides similar or better resolution as compared to the baseline TENO6 schemes for the same grid size.

The Evaluation of an Integral Equation Method for Two-Dimensional Shock-Free Flows

1975 ◽  
Vol 26 (1) ◽  
pp. 59-70 ◽  
Author(s):  
D Nixon ◽  
J Patel
Keyword(s):  
Integral Equation ◽  
Integral Equation Method ◽  
Free Flow ◽  
Equation Method ◽  
Computational Time ◽  
Test Cases ◽  
Two Dimensional ◽  
Exact Methods ◽  
Wide Range ◽  
Steady Shock

SummaryThe numerical aspects of the integral equation method developed by Nixon and Hancock for two-dimensional steady shock-free flow have been rationalised; this numerically refined method is evaluated by calculating the pressure distribution around a wide range of aerofoils. These test cases include aerofoils in supercritical shock-free flow as well as subcritical flow and exact solutions are available for comparison. The computational time in the present method is significantly less than that required by the exact methods. The present results compare satisfactorily with the exact results.

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