Computational Fluid Dynamics Lab (PFC–IV) AY 2023-24
Lab No.: 3
Name of the Lab: Computational Fluid Dynamics
Name of Student: Shubham Vijay Jadhav Section/ Batch: C4 Dat
Roll
No. 222
Aim: Explore discretization methods in 1D, 2D, and 3D meshing, emphasizing symmetry,
Mesh quality, and independence through a case study of internal flow scenarios.
Objectives: 1. Demonstrate proficiency in 1D, 2D, and 3D element meshing techniques.
2. Assess the impact of symmetry and ensure high mesh quality.
3. Apply acquired skills in a case study involving internal flow scenarios like
pipe flow or step geometries
4. As per the problem definition
1. Introduction:
Meshing
• Meshing in ANSYS refers to the process of dividing a complex geometry into small,
simple elements (such as triangles or quadrilaterals in 2D, or tetrahedra, hexahedra, or
prisms in 3D) to facilitate analysis using finite element methods (FEM). ANSYS
provides various tools and techniques for mesh generation to ensure accurate and
efficient simulation results.
• ANSYS provides various meshing tools to generate meshes efficiently. These tools
include:
• Automatic Meshing: ANSYS offers automatic meshing algorithms that can quickly
generate a mesh based on default settings. This is useful for simple geometries or
initial exploration.
• Manual Meshing: For more control over mesh quality and refinement, you can
manually specify mesh parameters, such as element size, curvature sensitivity, and
mesh transition controls.
• Mesh Controls: ANSYS allows you to apply mesh controls locally to refine or
coarsen the mesh in specific regions of the geometry. This is essential for capturing
details or reducing computational cost in areas of less interest.
• Mesh Metrics: ANSYS provides tools to evaluate mesh quality, such as aspect ratio,
skewness, and orthogonality, helping you ensure that the mesh is suitable for accurate
simulation.
• After generating the initial mesh, you may need to refine or optimize it based on
simulation requirements. This involves iteratively adjusting mesh parameters, refining
critical regions, and optimizing mesh density for better accuracy and efficiency.
Meshing is the second step in the whole simulation process. The meshing in the ANSYS comes
under the finite element method which is the method in which we convert one whole model into
finite smaller units or parts so that the accuracy in the result will be achieved.
Mesh Boundary
1. Geometry: - It is the first step in any kind of simulation. To draw the geometry which is
to be analyzed. Drawing of the geometry can be done using Mechanical Modeler or any
other software and then can be imported in. step or .igs file.
2. Mesh: - After the geometry creation the next step is to mesh the geometry. Meshing is the
process in which the geometry is divided in to finite elements or in easy words it is
division of geometry in parts.
3. Boundary Conditions: - These are the initial conditions or the inlet conditions given to the
fluid for example velocity, temperature and etc
4. Solve: - In this step the problem is being solved using the iterative methods or the
numerical method.
5. Post Processing: - This the observation step and the final step in this step we can see the
behavior of the fluid using contours, vectors, streamlines and etc.
Different Types of Mesh
Linear Quadratic Triangular
Elements Elements Elements
Hexa-Hedron Tetra-Hedron
Pyramind
Elements Elements
2. Methodology
The first step in the ANSYS meshing is the geometry. The geometry which was used is shown
below in the image.
Hex Dominant:
Fig. The geometry used for hex dominant structure
The second step is to generate the mesh and add method in ANSYS
After that changing the setting from automatic method to Hex Dominant
The mesh then becomes:
Fig. Sectional View
After repeating the same process for another geometry we obtained the new meshed images
Fig. Tetrahedrons Structure
3. Conclusion
• ANSYS gives more option for meshing and some of the methods were Hex Dominant and
Tetrahedrons which are been added above with all the steps and process.
• Meshing is one of the important aspects as meshing is a pre-processing process in which
accuracy of getting the solution depends. More the fine mesh more will be the accuracy
and meshing differ from different shapes and size.
