Page History

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Axial Velocity

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Profiles

Let's now compare look at the velocity profiles before and after the heated section. To do this, we need to first create lines after heated section

Insert > Location > Line
Name it "Postheat 1" and click OK. On the lower left panel, you will see Details of Postheat 1. Enter the following coordinates.

Point 1 (4.27,0,0)

Point 2 (4.27,0.0294,0)

Enter 50 for Samples. (This will be the number of sample points used when plotting data) Click Apply.

at x=1.83 m ((start of heated section), x=4.27 m (end of heated section) and x=6.045 m (end of mixing section).

First, create the line at x=1.83 mCreate Postheat 2.

Insert > Location > Line

Name it "Postheat 2x183" and click OK. On the lower left panel, you will see Details of Postheat 2. Enter the following coordinates (0.0294 m is the pipe radius).

Point 1 (54.27,0,0)
Point 2 (54.27,0.0294,0)

Enter 50 100 for Samples. Click Apply.

Continue the same step for creating line Outlet (Similarly create lines at x=4.27 m and x=6.045m)045 m.

Insert > Chart  Enter

Name this chart "Second Section Axial Velocity ProfileProfiles" as Name. You will see Details of Second Section Axial Velocity Profile appear on the lower left panel. Under General, give the chart Title as "Axial Velocity Profile".
 
Now click on Data Series tap to specify the location of the chart data.

Select the General tab and name the chart "Axial Velocity Profiles".

Select Data Series tab. Change the name of the first data series to x=1.83 m. Under Data Source, specify Preheat 3 x183 as Location for the first data series. Change the name to x=1.8m. Continue adding Data Source until we added all Preheat 3, Postheat 1, Postheat 2, and Outlet. Name them according to the figure shown below.

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Now we will specify the X Axis parameter. Click on X Axis tab. Next to Variable, choose Velocity u. Next we will specify the Y Axis parameter. Click on Y Axis tab. Next to Variable, choose Y. Click Apply. You will see First Section Axial Velocity Profile created under Report in the Outline tab.
This is what you should see in the Graphics window.

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Add a new data series by clicking on the "New" icon as shown below and repeat the above steps but for x=4.27 m.

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Add a third data series by clicking on the "New" icon and repeating the steps for x=6.045 m. You should then have three items in the Data Series tab.

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Specify x-axis variable: Velocity u

Specify y-axis variable: Y

Complete the plot. Here's what we get.

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We notice that the flow accelerates due to the heatingWhat we notice when comparing fully developed flow before and after heated section is that the flow increases in velocity after the heated section. As air is heated, the its density decreases. So the velocity has to increase to maintain the same mass flow rate.

Temperature

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Profiles

Now let's us look at the temperature profile before and after the heating section.

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