Compressible Flow in a Bent Pipe CFD Analyse

Overview of Compressible Flow in a Bent Pipe CFD Simulation using ANSYS Fluent

Project Description

This project involves simulating compressible flow inside a bent pipe to analyze the formation and effects of a shock wave. Air at 5°C enters the pipe with a Mach number of 0.9, causing an extreme pressure gradient that results in a shock wave. To accurately capture flow characteristics in high-gradient zones, gradient adaption in ANSYS Fluent is employed.

Geometry and Meshing

• Geometry Creation: Designed in ANSYS Design Modeler, featuring a bent pipe with a 3 cm diameter.
• Initial Meshing: Unstructured mesh grid created using ANSYS Meshing with 191,479 elements.
• Refined Meshing: After applying gradient adaption, the mesh refined to 1,450,983 elements.

Methodology: Compressible Flow in a Bent Pipe

• Solver Type: Density-based solver used for simulation.
• Simulation Type: Performed in Transient form.
• Viscous Model: K-Omega SST model employed for accurate fluid behavior capture, especially near walls.

Conclusion

The simulation reveals air entering the pipe with a Mach number of 0.9 and a temperature of 5°C, experiencing a significant pressure drop at the bend, known as a shock wave. The analysis requires a high-quality mesh, and the gradient adaption technique was utilized to refine the mesh in high y-plus zones.

• Pressure Drop: Approximately 120 kPa along the pipe, resulting in significant variable distribution.
• Due to the coarse tetrahedron mesh grid limitations, the y-plus value was addressed with mesh refinement through gradient adaption.