Summary of Fluid Flow Simulation in Pipe with Sudden Enlargement || Minor Loss || Analysis of Flow Through Pipe

Summary of "Fluid Flow Simulation in pipe with Sudden Enlargement || Minor Loss || Analysis of Flow Through pipe"

This video tutorial demonstrates how to perform a fluid flow simulation in a pipe featuring a sudden enlargement using ANSYS Workbench (2022 R1). The main focus is on modeling, meshing, setting boundary conditions, running the simulation, and visualizing results to understand fluid behavior and minor losses due to sudden enlargement in pipes.

Main Ideas and Concepts

• Objective: Simulate fluid flow through a pipe with a sudden enlargement to analyze velocity changes and flow behavior.
• Software Used: ANSYS Workbench 2022 R1 (or any installed version).
• Physical Setup: A pipe consisting of a smaller diameter section followed by a larger diameter section (sudden enlargement).
• Fluid: water (default material selected).

Detailed Methodology and Instructions

1. Starting the Project in ANSYS Workbench

• Open ANSYS Workbench and select the Analysis System.
• Choose Design Modeler for geometry creation.

2. Geometry Creation

• Set units to centimeters.
• Create primitive cylinders to represent pipe sections:
  • First cylinder: larger diameter, oriented along the x-axis.
  • Second cylinder: smaller diameter, also oriented along the x-axis but positioned to create a sudden enlargement.
• Use Boolean operations (unite) to combine the two cylinders into a single solid geometry.
• Convert the solid pipe into a hollow section by applying Thin Surface:
  • Select faces to keep.
  • Set wall thickness (example: 0.5 cm).
• Fill internal faces to define fluid volume inside the pipe.

3. Naming and Defining Zones

• Rename fluid zone inside the pipe as "water".
• Rename pipe walls as "pipe Wall".

4. Meshing

• Generate default mesh initially to reduce computational time.
• Specify boundary faces:
  • Inlet face.
  • Outlet face.
  • Wall faces (pipe walls).
• Mesh is transferable to Fluent for simulation.

5. Setup in Fluent

• Define number of processes (e.g., 4) for parallel computation.
• Specify gravity direction (usually y-direction, -9.81 m/s²).
• Select fluid material as water.
• Apply boundary conditions:
  • Velocity inlet (e.g., 1 m/s).
  • Outlet and wall boundary conditions set accordingly.
• Initialize the flow with standard initialization from the inlet.

6. Calculation Settings

• Set number of iterations (e.g., 20 for short runs, 500 for detailed runs).
• Choose visualization parameters:
  • Velocity contours.
  • Streamlines.
  • Wall shear or pipe wall parameters.
• Run the simulation.

7. Visualization and Post-Processing

• Adjust transparency of pipe walls for better visualization.
• Create streamlines starting from the inlet to observe flow paths.
• Modify legend and color scales for velocity contours.
• Animate the flow to observe fluid particle movement through the sudden enlargement.
• Save animations as video files for review.

Key Observations from Simulation

• Velocity decreases significantly as fluid passes from the smaller diameter pipe section to the larger diameter section (sudden enlargement).
• Fluid particles near pipe walls experience more resistance and move slower compared to particles near the pipe center.
• Particles at the center exhibit higher velocity and move ahead of those near the walls.
• Color contours and velocity streamlines visually depict these velocity variations.
• The simulation runs until all fluid particles exit the outlet, providing a dynamic view of flow behavior.

Lessons and Applications

• Sudden enlargement in pipes causes velocity drop and minor losses due to flow separation and resistance near walls.
• CFD simulations help visualize and quantify these effects.
• The methodology can be applied to other pipe geometries and fittings to analyze fluid behavior.
• Proper geometry preparation, meshing, and boundary condition setup are crucial for accurate simulation results.

Speakers/Sources Featured

• Primary Speaker: An unnamed instructor/demonstrator guiding through the ANSYS Workbench and Fluent simulation steps.

Notable Quotes

— 13:03 — « So when the fluid particles are coming to the large cross-section you might observe the velocity has been decreased. »

— 14:42 — « Particles which are along the wall or near to the walls of the pipe, they have some resistance to flow, whereas the particles which are moving through the center, they are moving with higher velocity. »

— 15:01 — « Particles which are along the wall have more resistance to flow; the particles which are at center have less resistance to flow and that's why you are able to see some of the particles are lagging whereas some of the particles are going ahead especially the particles which are at the center. »

— 15:16 — « You can see red balls shows the maximum velocity once it crosses the smaller section and enter the enlarged section you might observe again the variation in the velocity of each and every individual particle. »

— 16:12 — « How the fluid particle will behave when they are passing through such cross section can be easily understood with the help of the simulation which we are shown over here. »

Category

Educational

Video