[ElHombreMagnifico_CFD]

Hello everyone,
I'm working on a project where I need to plot the change of pressure from the inlet of my geometry to the outlet to visualize the change in gauge pressure as it traverses through the pipe segment. Please refer to the images added to this post for better understanding. I have a couple of questions regarding this:
Background:

• The flow is laminar, incompressible, and in a steady state.
• The simulation is being conducted using ANSYS Fluent.

Questions:

1. How to Plot Pressure Change from Inlet to Outlet:
   • I want to generate a plot to visualize the pressure change from the inlet to the outlet of the pipe segment.
   • The pipe segment has 2 inlets and a single outlet (see attached image)
2. Determining Pressure Drop Across a T-Junction:
   • How can I determine the pressure drop across one of the T-junction in a pipeline system?
   • Should the static- or total pressure be used to determine the pressure drop across pipe fittings for determining the associated loss coefficient?

I appreciate any insights or references to literature that can help with these questions.
Images for Reference:
Piping_segment_sketch.jpg
Thanks in advance for your help!

[Martin_Sz]

Here's how to address your questions about plotting pressure change and determining pressure drop in ANSYS Fluent:
Plotting Pressure Change:
* Surface Reports: Utilize Surface Reports in ANSYS Fluent to obtain average pressure values at the inlet and outlet faces.
* Create a Derived Quantity: Define a derived quantity in Fluent that subtracts the inlet average pressure from the outlet average pressure. This will represent the pressure change across the pipe segment.
* Line Plot: Generate a line plot using the derived quantity to visualize the pressure change along the flow path. You can create a line intersecting the inlet and outlet faces to extract pressure data along that path.
Determining Pressure Drop Across T-Junction:
* Surface Reports: Similar to above, use Surface Reports to obtain average static pressure values at the inlet and outlet of the T-junction you're interested in.
* Pressure Drop Calculation: Subtract the outlet's average static pressure from the inlet's average static pressure to determine the pressure drop across the T-junction.
* Loss Coefficient: Static pressure is recommended for calculating pressure drop across pipe fittings like T-junctions to determine the associated loss coefficient. This is because static pressure represents the usable energy in the fluid stream, and the loss coefficient accounts for energy dissipation due to the fitting.
Additional Tips:
* Ensure you're capturing pressure data at the appropriate locations (center of inlet/outlet faces) for accurate results.
* Consider using path functions in Fluent to extract pressure data along specific flow paths within the pipe segment.
For more in-depth information, refer to the ANSYS Fluent documentation on surface reports, derived quantities, and pressure monitors.

MORE AT LINK BELOW
https://howtooansys.blogspot.com/202...re-change.html

[ElHombreMagnifico_CFD]

Hi Marcin,
Thank you so much for your detailed explanation! Your instructions on using Surface Reports, creating a Derived Quantity, and generating a Line Plot in ANSYS Fluent are very clear and helpful.
I do have a couple of follow-up questions regarding the line creation for plotting the pressure change:

• Should the line be a centerline that makes its way from the inlet to the outlet? If so, could you provide more details on how to create this line in ANSYS Fluent?
• Based on my current understanding of line creation in Fluent, only two points can be defined for which a chart can be made. Should successive lines be placed after each other to traverse the entire axial flow path from inlet to outlet?

Any additional insights or step-by-step instructions would be greatly appreciated.
Thanks again for your help!

[Martin_Sz]

You're right that creating a single line with two points in Fluent limits you to data extraction along that specific path. To capture data across the entire axial flow path (centerline), you can create a rake entity in Fluent. Here's a general guideline:
* Go to the Operate menu and select Lines/Rakes.
* Choose ** Rake**.
* Define the starting and ending points of your rake line along the centerline.
* Set the number of points within the rake line. This defines the data resolution along the centerline.
Fluent will create a series of points along the centerline, allowing you to extract data and plot it versus the rake line's axial distance.

[ElHombreMagnifico_CFD]

Originally Posted by ElHombreMagnifico_CFD

Hello everyone,
I'm working on a project where I need to plot the change of pressure from the inlet of my geometry to the outlet to visualize the change in gauge pressure as it traverses through the pipe segment. Please refer to the images added to this post for better understanding. I have a couple of questions regarding this:
Background:

• The flow is laminar, incompressible, and in a steady state.
• The simulation is being conducted using ANSYS Fluent.

Questions:

1. How to Plot Pressure Change from Inlet to Outlet:
   • I want to generate a plot to visualize the pressure change from the inlet to the outlet of the pipe segment.
   • The pipe segment has 2 inlets and a single outlet (see attached image)
2. Determining Pressure Drop Across a T-Junction:
   • How can I determine the pressure drop across one of the T-junction in a pipeline system?
   • Should the static- or total pressure be used to determine the pressure drop across pipe fittings for determining the associated loss coefficient?

I appreciate any insights or references to literature that can help with these questions.
Images for Reference:
Attachment 100550
Thanks in advance for your help!

Step 1: Creating Lines for Static Pressure Data Extraction

1. Navigate to the Results Tab:
   • Click on Results in the ANSYS Fluent menu.
2. Create Lines:
   • Go to Surface > Create > Line/Rake.
   • Define the lines at key positions in the flow domain:
     • Line 1: From the center of the inlet to the center of the T-junction cross-section.
     • Line 2: From the second inlet to the center of the T-junction cross-section.
     • Line 3: From the first T-junction to the second T-junction.
     • Line 4: From the second T-junction to the center of the outlet.
   • Specify the coordinates for the start and end points of each line accurately.

Step 2: Create the XY Plot for Static Pressure

1. Open the XY Plot Dialog:
   • Go to Results > Plots > XY Plot.
2. Select Lines for the Plot:
   • In the XY Plot dialog, under the Surfaces section, select the lines you created in the previous step (Line 1, Line 2, Line 3, Line 4).
3. Set Plot Direction:
   • Set Plot Direction to X = 1 and Y = 1.
4. Set options:
   • Node Values
   • Position on X Axis
5. Configure the Axes:
   • Y-Axis Function:
     • Select Function as Pressure.
     • Choose Static Pressure from the drop down menu.
   • X-Axis Function:
     • Choose Direction Vector to plot the pressure variation along the direction of the lines.
6. Save/Plot