💥💥💥 How to improve orthogonal quality in Ansys Workbench?

Orthogonal quality is a mesh metric that measures how well the mesh elements are aligned with the flow direction. A high orthogonal quality means that the mesh faces are perpendicular to the flow, which is desirable for accuracy and stability. A low orthogonal quality means that the mesh faces are skewed or distorted, which can lead to numerical errors and poor convergence.

There are several ways to improve orthogonal quality in Ansys Workbench, depending on the type and complexity of your geometry and mesh. Here are some general tips:

• Use a structured mesh if possible, especially for simple geometries that can be swept or extruded. Structured meshes have higher orthogonal quality than unstructured meshes, because they have regular and aligned elements.
• Use inflation layers near the walls or boundaries, to capture the boundary layer effects and reduce the aspect ratio of the elements. Inflation layers can improve the orthogonal quality by creating smooth transitions from fine to coarse mesh regions.
• Use mesh controls to refine or coarsen the mesh in specific areas, such as regions of high curvature, sharp corners, or complex features. Mesh controls can help you optimize the mesh size and distribution, and avoid creating small or distorted elements that can lower the orthogonal quality.
• Use mesh smoothing or optimization techniques, such as Laplacian smoothing, Winslow smoothing, or Robust Mesh Optimization. These techniques can improve the mesh quality by adjusting the node positions or element shapes, while preserving the geometry fidelity and element volume.

You can check the orthogonal quality of your mesh in Ansys Workbench by using the Element Quality Plots feature¹, which shows you the distribution and location of the elements with different quality values. You can also use the Question Answering feature² to get more information about orthogonal quality from web sources.

What is the difference between structured and unstructured mesh?

The difference between structured and unstructured mesh is that structured mesh has a regular and predictable pattern of elements and nodes, while unstructured mesh has an arbitrary and irregular pattern of elements and nodes. Structured mesh is easier to generate, store, and solve, but it may not capture complex geometries accurately. Unstructured mesh can conform to any geometry shape, but it requires more memory, computation time, and data structures. You can find more information about the types of mesh in the web search results I have provided¹²³⁴.

How do I choose between structured and unstructured mesh?

Choosing between structured and unstructured mesh depends on various factors related to your specific simulation needs. Here are some considerations to help you decide:

• Complexity of Geometry: If you have a complex geometry where the shape is critical to the design, an unstructured mesh is advantageous because it can conform to any geometry with localized resolutions¹.
• Localized Regions of High Resolution: For models that require high-resolution mesh in localized regions, an unstructured mesh allows for such targeted refinement¹.
• Ease of Generation: Structured meshes are generally easier and faster to generate due to their regular pattern, which can be beneficial for simpler geometries or when computation time is a concern¹.
• Memory Requirements: Structured meshes are more memory-efficient because they require less data to define connectivity between elements¹.
• Computation Time: Structured meshes can lead to faster numerical solutions due to their regularity, which simplifies the computation process¹.
• Numerical Accuracy: For simple geometries, structured meshes may provide more accurate solutions and reduce errors caused by distorted cells².

In summary, if your geometry is not overly complex and does not require high-resolution meshing in specific areas, a structured mesh will likely suffice and save on computation time and memory. However, if you’re dealing with intricate shapes or need precise local detail, an unstructured mesh would be the better choice despite the greater memory requirement and potentially slower solve times¹. Always consider the trade-offs between these factors when making your decision.

What is the difference between tetrahedral and hexahedral elements?

The difference between tetrahedral and hexahedral elements is that tetrahedral elements have four triangular faces, while hexahedral elements have six quadrilateral faces. Tetrahedral elements are more suitable for representing complex geometries, but they are less accurate and more prone to distortion than hexahedral elements. Hexahedral elements can provide more accurate and stable solutions, but they are more difficult and time-consuming to generate for arbitrary shapes.

You can find more information about the types of mesh and their advantages and disadvantages in the web search results I have provided¹²³⁴⁵. 

What is the difference between triangular and quadrilateral elements?

The difference between triangular and quadrilateral elements is that triangular elements have three sides and three vertices, while quadrilateral elements have four sides and four vertices. Triangular elements can be used to mesh any shape of domain, but they may not be very accurate or efficient for some problems. Quadrilateral elements can provide better accuracy and efficiency for some problems, but they may not be able to mesh complex shapes of domains.

You can find more information about the types of elements and their advantages and disadvantages in the web search results I have provided¹²³⁴⁵.