Rotating Disk Effect on Surrounding Airflow CFD Simulation

This INTERMEDIATE level ANSYS Fluent CFD simulation tutorial explores the effect of a rotating disk on surrounding airflow, with a specific focus on implementing and analyzing the moving wall boundary condition. The episode is designed to provide a comprehensive understanding of fluid dynamics around rotating objects using a stationary frame approach.

Key aspects of this intermediate-level simulation include:

Rotating Disk Geometry: Analysis of a pre-designed model featuring a rotating disk within a stationary enclosure, focusing on the interaction between the moving surface and the surrounding air.

Moving Wall Boundary Condition: Detailed implementation and configuration of the moving wall boundary condition in ANSYS Fluent to accurately represent the rotating disk surface without using a rotating reference frame.

Turbulence Modeling: Application of appropriate turbulence models (such as k-ε, k-ω, or SST) to capture the complex flow patterns induced by the rotating disk, including boundary layer effects and wake regions.

Velocity Profiles: Examination of velocity distributions in the vicinity of the rotating disk, including the formation of boundary layers and secondary flow patterns in a stationary frame of reference.

Pressure Distribution: Analysis of pressure variations across the disk surface and in the surrounding air, including low-pressure regions that may lead to vortex formation.

Mesh Considerations: Discussion on mesh requirements for accurately capturing the flow features near the rotating surface, including boundary layer resolution and mesh quality near the moving wall.

Solution Stability: Techniques for ensuring and improving solution stability when dealing with moving wall boundary conditions.

Performance Metrics: Calculation and interpretation of key parameters such as torque on the disk, drag coefficients, and the disk’s effect on surrounding air movement.

Advanced Post-Processing: Utilizing ANSYS post-processing tools to visualize and quantify complex flow structures, including streamlines, vorticity contours, and velocity vectors in the stationary frame.

This intermediate-level training aims to enhance participants’ skills in simulating and analyzing flows involving moving boundaries using ANSYS Fluent, specifically focusing on the moving wall boundary condition. It provides insights into the challenges of modeling rotating surfaces without resorting to rotating reference frames.

The tutorial focuses on the setup, solving, and analysis phases of the CFD simulation, using a pre-defined disk geometry and mesh. This approach allows students to concentrate on understanding the physics of flows around rotating surfaces, applying appropriate models and boundary conditions, and interpreting results in the context of rotating machinery applications.

Participants will gain valuable experience in handling more complex CFD simulations involving moving parts, preparing them for advanced analysis of rotating machinery, fans, and other applications involving moving walls in real-world engineering scenarios, all within a stationary frame of reference.