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Graphic Techniques Used in CFD

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Introduction Can you understand your results by looking at a

table of numbers on a computer screen ?

Computer graphics and computational flow

visualization provide powerful means of

examining results.

For examples

Contour plots can provide

a good means of assessing sharpness of shocks

for checking that there are no incorrect flow gradients next to

farfield boundaries.

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Introduction

Techniques xy Plots

Contour Plots

Vector and streamline Plots

Mesh Plots

Composite Plots

Animations

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xy Plots Some examples of xy plots

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xy Plots

Advantages

xy plots are the simplest and most straightforward

category of graphical representation of CFD results.

They are still remain the most precise quantitative

way to present numerical data on a graph.

Another person can readily read quantitative data from

curves on an xy plot without making any mental or arithmetic

interpolation.

Disadvantage

They do not illustrate the global nature of a set CFD

results all in one view.

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Contour Plots What is a contour line ?

It is a line along which some property is constant.

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Contour Plots Another type of contour plot is flooded contour.

Instead of illustrating flow with a discrete number of contour

lines, the regions between these lines are simply filled with a

color intensity that denotes the value of the flow-field property-

the regions between the lines are flooded with color intensity.

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Contour Plots

More examples of flooded contours

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Contour Plots Multizone three-dimensional contour plot

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Contour Plots In CFD, contour plots are one of the most commonly

found graphical representations of data.

The global nature of the flow is seen in one single view.

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Vector and Streamline Plots A vector plot is a display of a vector quantity at discrete grid points,

showing both magnitude and direction, where the base of each vector

is located at the respective grid point.

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Vector and Streamline Plots Illustrations of streamlines are excellent tools for examining

the nature of a flow.

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Vector and Streamline Plots More examples of streamline plots

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Mesh Plots

Mesh plots consist of lines connecting grid points in

either a two- or three-dimensional grid.

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Mesh Plots

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Composite Plots Many of the categories of different plots can be combined

into a single plot, called a composite plot.

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Composite Plots

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Animations