Mesh locking is a crucial feature in computational simulation software that allows users to preserve a specific mesh structure, detaching it from dynamic solution data and making it an independent component of the model. Essentially, it "freezes" the current mesh configuration.
This functionality is particularly useful for managing simulation data, optimizing disk space, and ensuring the reproducibility of analyses.
Why Lock a Mesh?
Locking a mesh provides several significant advantages, primarily revolving around data management, efficiency, and consistency in simulation workflows:
- Preserving Adapted Meshes: One primary use case is when working with an adapted mesh. An adapted mesh is one that has been automatically refined or coarsened by the software based on previous solution results to improve accuracy in specific areas (e.g., high-stress regions in structural analysis, steep gradients in fluid flow). Mesh locking allows you to keep this precise, adapted mesh even if you need to clear the solution data that initially generated it. This is invaluable for running subsequent simulations with the identical optimized mesh without recalculating the adaptation process.
- Optimizing Disk Space: If you anticipate working with a fixed mesh – meaning its structure will not change throughout your analysis – locking it can lead to substantial disk space savings. By locking the mesh, it becomes a static entity separate from potentially large, transient solution files. This is especially beneficial for large-scale models or when archiving projects.
- Ensuring Model Independence: A locked mesh functions independently of other data within the model. This means that changes to input parameters, boundary conditions, or even unrelated parts of the model will not inadvertently trigger a re-meshing or adaptive mesh refinement process, unless explicitly unlocked. This independence guarantees consistency and prevents unintended mesh modifications.
- Reproducibility and Comparison: For comparative studies or design iterations, using an identical mesh across different simulations is vital for consistent results. Locking the mesh ensures that every run starts with the exact same spatial discretization, enabling direct and reliable comparison of different design parameters or load cases.
How Mesh Locking Works
In numerical simulation methods like Finite Element Analysis (FEA) or Computational Fluid Dynamics (CFD), the model's geometry is divided into a mesh of discrete elements.
- Adaptive Meshing Process: During an adaptive simulation, the software iteratively refines or coarsens the mesh based on error indicators derived from the solution. This process generates an optimal mesh that is highly suitable for the specific physics and solution accuracy requirements.
- The Locking Action: Once an engineer is satisfied with a particular mesh state – whether it's a manually generated mesh or an adaptively refined one – they can activate the "lock mesh" function. This action instructs the software to save the current mesh configuration as a permanent, standalone component.
- Decoupling Data: After locking, the mesh is effectively decoupled from the solution data. You can then delete the bulky solution files to free up disk space, knowing that the specific mesh structure remains intact and ready for future use.
Practical Applications and Benefits Summary
| Feature | Before Locking | After Locking |
|---|---|---|
| Mesh State | Dynamic, adaptive, tied to solution data | Static, fixed, independent of solution data |
| Solution Data | Required to maintain adapted mesh | Can be cleared without losing mesh structure |
| Disk Space | Potentially larger due to dynamic data | Optimized for fixed mesh |
| Re-simulation | Mesh may re-adapt or re-generate | Uses exact same locked mesh |
| Consistency | Mesh might change with re-runs | Guaranteed identical mesh for all runs |
Common Use Cases:
- Scenario Comparison: Running multiple "what-if" scenarios (e.g., varying material properties, boundary conditions, or fluid inlets) on the exact same adapted mesh to ensure that observed differences in results are due to the parameter changes, not meshing variations.
- Design Validation: After an iterative design process that includes mesh adaptation, lock the final mesh for comprehensive validation runs. This secures the mesh and allows for efficient archiving of the design.
- Collaborative Workflows: Sharing a model with a locked mesh ensures that all team members are working with the identical mesh setup, promoting consistency and reducing errors across a project.
- Long-term Archiving: When archiving projects, locking the mesh before clearing solution data significantly reduces file size while preserving the detailed mesh for future reference or re-analysis.
Mesh locking is a powerful tool for managing simulation data, enhancing reproducibility, and optimizing computational resources. It separates the geometric discretization from the transient solution data, giving users greater control over their simulation workflows and ensuring consistency in their analyses.
