Virtual Control Volumes for Two-Dimensional Unstructured Elliptic Smoothing

2010 ◽  
pp. 121-142 ◽  
Author(s):  
Steve L. Karman
Keyword(s):  
Two Dimensional ◽  
Virtual Control ◽  
Elliptic Smoothing ◽  
Control Volumes

scholarly journals A Two Dimensional Flow Analysis Model for Designing a Nozzle-Less Volute Casing for Radial Flow Gas Turbines

1991 ◽  
Author(s):  
H. O. Owarish ◽  
M. Ilyas ◽  
F. S. Bhinder
Keyword(s):  
Gas Turbines ◽  
Control Volume ◽  
Flow Analysis ◽  
Two Dimensional ◽  
Analysis Model ◽  
Cross Sectional ◽  
Analysis And Design ◽  
Single Entry ◽  
Two Dimensional Flow ◽  
Control Volumes

This paper describes a two dimensional model for flow analysis and design of a single entry nozzle-less volute casing for inward flow radial turbines. The model takes into account the cross-sectional shape of the casing by dividing it into a number of segments which are further sub divided into control volumes. Changes in flow properties are calculated by considering the changes in momenta of fluid in the tangential and the radial directions across each control volume. The model, has been computerized using Fortran 77 for the IBM AT or 100% compatible micro computers.

The Construction of a Conservative Radiation Hydrodynamics Algorithm in Two-Dimensional Spherical Geometry

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Zhiwei Lin ◽  
Shaoen Jiang ◽  
Lu Zhang
Keyword(s):  
Radiation Transport ◽  
Spherical Geometry ◽  
Artificial Viscosity ◽  
Radiation Hydrodynamics ◽  
Two Dimensional ◽  
Hydrodynamic Equations ◽  
Spherical Coordinates ◽  
Spatial Control ◽  
Lagrangian Hydrodynamics ◽  
Control Volumes

Abstract This paper presents the construction of a conservative radiation hydrodynamics algorithm in two-dimensional (2D) spherical geometry. First, we discretize the radiation transport equation (RTE) in that geometry. The discretization preserves the conservation of photons by integrating the original RTE in 2D spherical coordinates over both angular and spatial control volumes. Some numerical results are provided to verify the discretization for both optically thin and thick circumstances. Second, we formulate the staggered Lagrangian hydrodynamics in that geometry. The formulation preserves the conservation of mass, momentum, and energy by integrating the original hydrodynamic equations in 2D spherical coordinates over their respective control volumes. The original edge-centered artificial viscosity in 2D cylindrical geometry is also extended to be capable of capturing shock waves in 2D spherical geometry. Several 2D benchmark cases are provided to verify the scheme. The subsequent construction of the conservative radiation hydrodynamics algorithm is accomplished by the combination of the staggered Lagrangian hydrodynamics scheme and the solution of the RTE in 2D spherical geometry. Several 2D problems are calculated to verify our radiation hydrodynamics algorithm at the end.

Finite Difference Analysis of Laminar Separated Forced Convection in Cavities

1984 ◽  
Vol 106 (1) ◽  
pp. 49-54 ◽  
Author(s):  
A. Bhatti ◽  
W. Aung
Keyword(s):  
Boundary Layer Thickness ◽  
Average Nusselt Number ◽  
Numerical Technique ◽  
Reynolds Numbers ◽  
Two Dimensional ◽  
Uniform Temperature ◽  
Difference Analysis ◽  
Aspect Ratios ◽  
Side Walls ◽  
Control Volumes

Results are presented for a comprehensive numerical analysis of the two-dimensional heat transfer in cavities of rectangular profiles. The walls of the cavity are held at a uniform temperature and calculations are carried out at various aspect ratios and Reynolds numbers in laminar flow. The numerical technique is based on a hybrid upwind/central differencing of the governing differential equations that are first integrated over control volumes surrounding the node points in a rectilineal, nonuniform grid system. Results indicate that while the average Nusselt number in the cavity is related to the Reynolds number raised to a power, the latter depends on the aspect ratio and varies between the cavity floor and the side walls. The influence of the upstream boundary layer thickness is found to be negligible. The numerical results are found to be well represented by the following equation: Nu¯t=0.0345(Res)0.46(w/s)−0.142

Computational Fluid Dynamics-Heat Transfer Meshless Control Volume Method

2004 ◽  
Author(s):  
Ali Arefmanesh ◽  
Mohammad Najafi ◽  
Hooman Abdi
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Control Volume ◽  
Numerical Technique ◽  
Computational Domain ◽  
Two Dimensional ◽  
Control Volume Method ◽  
Control Volumes ◽  
Volume Method

A novel meshless numerical technique to solve computational fluid dynamics-heat transfer problems is introduced. The theory behind the newly proposed technique hereafter named “The Meshless Control Volume Method” is explained and a number of examples illustrating the implementation of the method is presented. In this study, the technique is applied for one and two dimensional transient heat conduction as well as one and two dimensional advection-diffusion problems. Compared to other methods including the exact solution, the results show to be highly accurate for the considered cases. Being a meshless technique, the control volumes are arbitrary chosen, and they posses simple shapes which contrary to the existing control volume methods can overlap. The number of points within each control volume and, therefore the degree of interpolation can be different throughout the considered computational domain. Since the control volumes are of simple shapes, the integrals can be evaluated analytically.

A Two-Dimensional Flow Analysis Model for Designing a Nozzle-less Volute Casing for Radial Flow Gas Turbines

1992 ◽  
Vol 114 (2) ◽  
pp. 402-410 ◽  
Author(s):  
H. O. Owarish ◽  
M. Ilyas ◽  
F. S. Bhinder
Keyword(s):  
Gas Turbines ◽  
Control Volume ◽  
Flow Analysis ◽  
Two Dimensional ◽  
Analysis Model ◽  
Cross Sectional ◽  
Analysis And Design ◽  
Single Entry ◽  
Two Dimensional Flow ◽  
Control Volumes

This paper describes a two-dimensional model for flow analysis and design of a single entry nozzle-less volute casing for inward flow radial turbines. The model takes into account the cross-sectional shape of the casing by dividing it into a number of segments, which are further subdivided into control volumes. Changes in flow properties are calculated by considering the changes in momenta of fluid in the tangential and radial directions across each control volume. The model has been computerized using Fortran 77 for the IBM AT or 100 percent compatible microcomputers.

A Meshless Local Petrov-Galerkin Method for Fluid Dynamics and Heat Transfer Applications

2005 ◽  
Vol 127 (4) ◽  
pp. 647-655 ◽  
Author(s):  
Ali Arefmanesh ◽  
Mohammad Najafi ◽  
Hooman Abdi
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Galerkin Method ◽  
Control Volume ◽  
Numerical Technique ◽  
Transient Heat Conduction ◽  
Computational Domain ◽  
Two Dimensional ◽  
Control Volumes ◽  
Volume Method

The meshless local Petrov-Galerkin method has been modified to develop a meshless numerical technique to solve computational fluid dynamics and heat transfer problems. The theory behind the proposed technique, hereafter called “the meshless control volume method,” is explained and a number of examples illustrating the implementation of the method is presented. In this study, the technique is applied for one- and two-dimensional transient heat conduction as well as one- and two-dimensional advection-diffusion problems. Compared to other methods, including the exact solution, the results appear to be highly accurate for the considered cases. Being a meshless technique, the control volumes are arbitrarily chosen and possess simple shapes, which, contrary to the existing control volume methods, can overlap. The number of points within each control volume and, therefore, the degree of interpolation, can be different throughout the considered computational domain. Since the control volumes have simple shapes, the integrals can be readily evaluated.

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.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

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