Dual Blade Lawnmowers Simulations for Airflow and Clippings Dynamics​ (ABP)

This Application Best Practice (ABP) provides a step-by-step guide for simulating airflow and grass clippings dynamics in dual blade lawnmowers using Ansys software tools. It is designed for advanced users and takes approximately two hours to complete. The ABP leverages a combination of Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) to model the complex interactions between rotating blades, airflow, and flexible grass particles.

Learning Outcomes:

Following completion of this Application Best Practice (ABP), you will be able to:

• Understand the principles of CFD-DEM coupling and how it applies to simulating airflow and particle dynamics in lawnmower systems.
• Gain proficiency in setting up dynamic mesh simulations in Ansys Fluent® fluid simulation software for rotating blade configurations with overlapping regions.
• Learn to model flexible fiber particles representing grass clippings using Ansys Rocky™ particle dynamics simulation software, including breakage criteria and motion frames.
• Develop skills in exporting and integrating CFD results into DEM simulations for accurate representation of airflow effects on particles.
• Analyze post-processing results such as torque, shear work, and clumping to evaluate blade performance and optimize mower design.

Prerequisites:

• • Ansys Rocky Tutorial: Transfer Chute | Ansys Innovation Courses
  • Ansys Rocky: Static Angle of Repose Test | Ansys Courses
  • Chapter 14: Tutorial - Fluidized Bed
  • Chapter 17: Tutorial - Mixing Tee
  • Chapter 22: Tutorial - Lawn Mower
  • Ansys Fluent Dynamic Mesh Modeling
  • Chapter 16: Using Overset and Dynamic Meshes

Please note: These training materials were developed and tested in the 2025R2 release.

Application Best Practices (ABPs) outline engineering design goals for specific applications and provide guidance for how to achieve those goals using Ansys simulation software. It is important to note that a Geometry File or other Input Files are not always available. ABPs, as opposed to the official training-material workshops/tutorials, are not meant to be a step-by-step instruction document. ABPs are a link between product-based training courses and application specific tutorials, educating on the "how" and "why" of the best modeling approach, highlighting best practices and workflows for a particular application.

Alternate video link.