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The simulation results follow the experimental data quite closely, the general trend is that pressure decreases (almost linearly) as we move from the inlet towards the outlet of the pipe.

Axial Velocity Profile

Now, let's us look at investigate the axial velocity profile at various location in different lengths along the pipe. We are especially interested in the flow development before it enters the heated section and would like to observe how heat addition in the heated section will affect the flow development. To do this, let's start with investigation the flow before the heated section.. Then please divert your attention to the difference heat addition has on flow development.

Axial Velocity Profile before Heated Section

The heated section is from x-positions of 1.83m to 4.27m. Let's create 4 lines before To allow us insight into flow development before the heated section, we will begin by creating 4 lines of x-position less than 1.83m in the pipe.

Insert > Location > Line

Name it The first line will be to define the inlet. Accordingly, please name this line "Inlet" and click OK. On the lower left panel, you will see Details of Inlet. Enter the following coordinates. The coordinates are entered in terms of (x,y,z).

Point 1 (0,0,0)

Point 2 (0,0.0294,0)

We want to create a vertical line, parallel to the y axis, so check to make sure that the x and z coordinates are the same for both points.

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

Click Apply.Create Preheat 1.

Insert > Location > Line

Name it Now we will define the second line, calling this "Preheat 1" and click OK. On the lower left panel, you will see Details of Preheat 1. Enter the following coordinates.

Point 1 (0.6,0,0)

Point 2 (0.6,0.0294,0)

Enter Again, enter 50 for Samples. (This will be the number of sample points used when plotting data)

Click Apply.

Click Apply.

Please repeat the process for Continue the same step for creating line Preheat 2 (x=1.2m2) , Preheat and 3 (x=1.8m8).

Check that you have the following under Outline.
Image Removed
 

To double check, the coordinates for the 4 lines should be:

Check that you have the following under Outline.

Image Added
  

Now that we have enough intervals to understand Now we will have enough interval to look at the flow development before the heating.   Let's We should create a chart to investigate thisof the velocity profile at these lines.

Insert > Chart 
Enter "First Section Axial Velocity Profile" as Name. You will see Details of First Section Axial Velocity Profile appear on the lower left panel. Under General, give the chart Title as "Axial Velocity Profile".

Now click on Select the Data Series tap tab to specify the location of the chart data. Create a new data series .  Under Data Source, specify Inlet as Location. Change the name to Inlet. Continue adding Data Source until we added all Inlet, Preheat 1, Preheat 2, and Preheat 3. Name them according to the figure shown below.

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https://confluence.cornell.edu/download/attachments/111221576/Axial%20Velocity%20Profile.png

Notice preheat 2 and preheat 3 lines yield almost the same velocity profile. This tells us that after preheat 2, the flow has become mostly developed. So we can assume that the flow is developed after 1.2 meters.

Axial Velocity Profile before and after Heated Section

Let's To make things more interesting, let's now compare the velocity profiles of 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.

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https://confluence.cornell.edu/download/attachments/111221576/Axial%20Velocity%20Profile%20after.png

The flow is accelerated in the heated sectionWhat 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 particle is heated, the density is reduced and therefore the mass is decreased. However, momentum of the air particle is conserved therefore to compensate for the smaller mass, the velocity must increase.

Temperature Profile

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

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