Ansys Fluent: Validating Printed Circuit Heat Exchanger Model with NIST CO2 and Non-Conformal Mesh

 Validating Printed Circuit Heat Exchanger Model in Ansys Fluent

Here's a breakdown of your questions and some insights to help validate your research paper:

1. NIST Real Gas Model for CO2 in Fluent:

• The error you're encountering with the NIST real gas model for CO2 in Fluent could be due to a few reasons:
• Incorrect File Path: Double-check the path to your CO2 data file ("co2.fld"). Ensure it's located in a directory accessible by Fluent.
• Model Selection: Verify if you've selected "CO2" in the real gas model selection after enabling NIST real gas.
• Software Compatibility: Check the Fluent documentation for compatibility between your Fluent version and the specific NIST real gas model you're trying to use. Some models might require specific versions.

Here are some additional tips for using the NIST real gas model:

• Material Properties: Ensure you've defined the specific material properties for CO2 relevant to the NIST real gas model.
• Convergence Issues: Using a real gas model can sometimes lead to convergence difficulties. Start with a coarser mesh and gradually refine it while monitoring convergence.
• Fluent Tutorials: Refer to Fluent tutorials or user guides for examples of using NIST real gas models.

2. CHT Simulation and Non-Conformal Mesh:

• You're correct! CHT simulations in Fluent can work well with non-conformal meshes at the fluid-solid interface.
• Non-conformal meshes offer flexibility in mesh generation, especially for complex geometries like printed circuit heat exchangers.
• Fluent uses appropriate interpolation techniques to handle the non-conformity at the interface, ensuring accurate heat transfer calculations.

Here are some additional points to consider for CHT with non-conformal meshes:

• Mesh Quality: While non-conformal meshes are acceptable, ensure good overall mesh quality for accurate results. Elements should be well-shaped and avoid high aspect ratios.
• Refinement: Pay attention to the mesh refinement near the fluid-solid interface for capturing heat transfer gradients effectively.
• Convergence: Monitor convergence closely. Non-conformal meshes can sometimes lead to slower convergence compared to conformal meshes.

By addressing the potential issues with the NIST real gas model and using a well-refined non-conformal mesh, you should be able to achieve a successful CHT simulation for your printed circuit heat exchanger model.