...
One can plot vectors in the entire domain, or on selected surfaces. Here, the vectors will be plotted for the entire domain. First, click on Graphics & Animations . Next, double click on Vectors which is located under Graphics. Then, click on Display in the Vectors menu. You should obtain, the following output.
https://confluence.cornell.edu/download/attachments/118771111/VectPlot_Full.png
You can use the wheel button of the mouse to zoom into the region that closely surrounds the plate, to get a better view of the boundary layer velocities.
https://confluence.cornell.edu/download/attachments/118771111/VectPlot2_Full.png
Outlet Velocity Profile
In this section we will first plot the variation of the x component of the velocity along the outlet. Then we will plot the Blasius solution to see how the numerical solution compares. In order to start the process (Click) Results > Plots > XY Plot... > Set Up.. as shown below.
https://confluence.cornell.edu/download/attachments/118771111/xyplotsetup_Full.png
In the Solution XY Plot menu make sure that Position on Y Axis is selected , and X is set to 0
and Y is set to 1
. This tells FLUENT to plot the y-coordinate value on the ordinate of the graph. Next, select Velocity... for the first box underneath X Axis Function and select X Velocity for the second box. Please note that X Axis Function and Y Axis Function describe the x and y axes of the graph, which should not be confused with the x and y directions of the geometry. Finally, select outlet under Surfaces since we are plotting the x component of the velocity along the outlet. This finishes setting up the plotting parameters. Your Solution XY Plot menu should look exactly the same as the following image.
newwindow
Now, click Plot. The plot of the x component of the velocity as a function of distance along the outlet now appears. newwindow
https://confluence.cornell.edu/download/attachments/118771111/XVelPlot1_Full.png
In order to increase the legibility of the graph, we will plot the data as a line rather than points. To turn on the line feature, click on Curves... in the Solution XY Plot menu. Then, set Pattern to ----, set the Weight to 2
and select nothing for Symbol, as shown below.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/Curv2_Full.png
Now, the range of the y axis will be truncated, as we are not interested in far field velocity. Furthermore, the grid lines will be turned on. In order to implement these two changes. First click Axes in the Solution XY Plot menu. Next, select Y for Axis, deselect Auto Range, select Major Rules, select Minor Rules. Then, set Minimum to 0
and set Maximum to 0.12. Your Axes - Solution XY Plot menu, should look exactly like the image below.
newwindow
Then, click Apply in the Axes - Solution XY Plot menu. Now, select X for Axis and select Major Rules and Minor Rules, as shown below.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/Axes2_Full.png
https://confluence.cornell.edu/download/attachments/118771111/Plot5_Full.png
It is of interest to compare the numerical velocity profile to the velocity profile obtained from the Blasius solution. In order to plot the theoretical results, first click here to download the necessary file. Save the file to your working directory. Next, go to the Solution XY Plot menu and click Load File... and select the file that you just downloaded, BlasiusU.xy. Lastly, click Plot in the Solution XY Plot menu. You should then obtain the following figure.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/Plot6_Full.png
Mid-Section Velocity Profile
Here, we will plot the variation of the x component of the velocity along a vertical line in the middle of the geometry. In order to create the profile, we must first create a vertical line at x=0.5m, using the Line/Rake tool. First, (Click) Surface < Line/Rake as shown in the following image. newwindow
https://confluence.cornell.edu/download/attachments/118771111/SurfLinRake_Full.png
We'll create a straight vertical line from (x0,y0)=(0.5,0) to (x1,y1)=(0.5,0.5). Select Line Tool under Options. Enter x0=0.5
, y0=0
,x1=0.5
, y1=0.5
. Enter line1
under New Surface Name. Your Line/Rake Surface menu should look exactly like the following image.
Next, click Create. Now, that the vertical line has been created we can proceed to the plotting. Click on Plots, then double click XY Plot to open the Solution XY Plot menu. In the Solution XY Plot menu, use the settings that were used from the section above, except select line1 under Surfaces and deselect any other geometry sections. Make sure that Write to File is not selected, then click Plot. You should obtain the following output.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/Plot1M_Full.png
Once again, return to the Solution XY Plot menu, select Write to File, then click Write.... When prompted for a filename, enter XVelProfs.xy and save the file in your working directory.
Pressure Coefficients
In this section we will create contour plots for the pressure coefficients. Before we begin, we must first set the reference values for velocity. In order to do so, first click on Reference Values then set Compute from to inlet, as shown below.
...
|^CompInlet_Full.png]
Next, click on Graphics and Animations, then double click on Contours, as shown below.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/ContPlot_Full.png
https://confluence.cornell.edu/download/attachments/118771111/Contou_Full.png
Lastly, click Display in the Contours menu to generate the contour plot. You should obtain the following output. newwindow
https://confluence.cornell.edu/download/attachments/118771111/ContP1_Full.png
You can then zoom in to the leading edge of the plate with the wheel mouse button as shown below.
newwindow
Skin Friction Coefficient
Here, the skin friction coefficient will be plotted as a function of distance along the plate. First, click on Plots, then double click on XY Plot. In the Solution XY Plot menu deselect Write to File, select Position on X Axis, set X to 1
and set Y to 0
. Then, set the box located underneath Y Axis Function to Wall Fluxes and set the box below to Skin Friction Coefficient. Next, select plate under Surfaces and deselect any other geometry features. At this point your Solution XY Plot menu should look the same as the following image.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/SolXY3_Full.png
https://confluence.cornell.edu/download/attachments/118771111/SkinFric1_Full.png
It is of interest to compare the numerical skin friction coefficient profile to the skin friction coefficient profile obtained from the Blasius solution. In order to plot the theoretical results, first click here to download the necessary file. Save the file to your working directory. Next, go to the Solution XY Plot menu and click Load File... and select the file that you just downloaded, BlasiusSkin.xy. Lastly, click Plot in the Solution XY Plot menu. You should then obtain the following figure.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/SkinFric2_Full.png
Drag
Now, we will obtain the drag on the plate. First, click on Report then click on Result Reports..., as shown in the following image.
newwindow
Next, double click on Forces and click Print in the Force Reports menu. You should then obtain the following output in the command pane.
newwindow
https://confluence.cornell.edu/download/attachments/118771111/ForceRep_Full.png
In the case here, the density, viscosity velocity and area all have values of 1. Thus, the equation above reduces to the following equation.
The results from ANSYS FLUENT agree with the theory here since the drag coefficient is approximately twice the value of the drag.
Now, save your work in the FLUENT window, then close the FLUENT window.
Go to Step 7: Verification & Validation
See and rate the complete Learning Module