Structured Mesh in CFD Analysis: Definition, Advantages & Disadvantages

 In CFD (Computational Fluid Dynamics) analysis, a structured mesh is a specific type of mesh generation used to discretize the computational domain. Here's a breakdown of the key characteristics:

Structure:

• Elements: Structured meshes consist of elements that have a regular, repeating pattern. These elements are typically hexahedrons (3D) or quadrilaterals (2D).
• Implicit Connectivity: The connectivity between elements is implicit in a structured mesh. This means that the neighboring elements for any given element can be easily identified based on its position in the grid. Imagine a checkerboard pattern – each square "knows" its neighbors based on its location on the board.
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Advantages:

• Simplicity: Due to the regular structure and implicit connectivity, structured meshes are easier to generate and implement in CFD codes.
• Efficiency: The well-defined element shapes and predictable neighbor relationships allow for efficient calculations, potentially leading to faster simulations.
• Accuracy: Structured meshes can be highly accurate for simple geometries with aligned boundaries.

Disadvantages:

• Complexity for intricate geometries: Structured meshes can become very complex and time-consuming to generate for intricate geometries with curved surfaces. Imagine trying to fit a square grid onto a circle.
• Limited flexibility: Adapting a structured mesh to complex geometries often requires breaking the domain into multiple blocks with potentially mismatched interfaces, which can introduce numerical errors.

Use Cases:

• Structured meshes are often preferred for simple geometries like ducts, pipes, or airfoils where the flow is well-aligned with the coordinate system.
• They can also be beneficial in cases where high accuracy and computational efficiency are priorities.

Comparison to Unstructured Meshes:

• Unstructured meshes, on the other hand, can be used for complex geometries but may require more computational resources and have slightly lower accuracy compared to structured meshes for simple geometries.

In conclusion, structured meshes offer advantages in terms of simplicity, efficiency, and accuracy for well-suited geometries. However, their inflexibility for complex shapes makes unstructured meshes a more versatile option in many CFD applications.