Rhino CFD Simulation Using tensorHVAC-Pro & tCFD Tools

A Practical Workflow for Architects, Engineers, and Product Designers

Integrating CFD into the design process is now easier than ever for Rhino users. With the combination of Rhinoceros 3D, tCFD-Pre, and tensorHVAC-Pro, you can build your geometry, define boundary conditions, generate a mesh, and run a full CFD analysis without needing to construct a traditional negative domain. This streamlined workflow saves time and effort—perfect for architectural airflow studies, HVAC design, external aerodynamics, and industrial applications.

This article walks through the full end-to-end process.

1. Prepare Geometry in Rhinoceros (Rhino)

The first step is to model your geometry inside Rhinoceros 3D. Rhino’s precision modeling tools make it ideal for creating detailed surfaces and volumes for CFD analysis.

Key preparation steps:

• Model your domain as positive geometry only (buildings, ducts, obstacles, vehicles, etc.)

• Unlike many traditional CFD packages, you do NOT need to create a negative fluid domain. tensorHVAC-Pro will generate this automatically during meshing

• Make sure all surfaces that will later become CFD boundary conditions (inlet, outlet, wall, symmetry, etc.) are clean, watertight, and separable

• Assign layers in Rhino if needed to organize different surface groups

Once your geometry is complete and cleaned up:

Export the model as STL

This is the preferred format for tCFD-Pre and ensures consistent meshing downstream.

2. Import Geometry into tCFD-Pre and Define Boundaries

Next, open tCFD-Pre, the pre-processing tool for defining CFD model inputs.

Workflow inside tCFD-Pre:

1. Import the STL file exported from Rhino

2. The software will automatically recognize individual surface patches

3. Select these surfaces and assign them to CFD boundary types, such as:

   • Velocity Inlet

   • Pressure Outlet

   • Walls

   • No-slip / free-slip boundaries

   • Fans, heat sources, or custom patches

4. Specify fluid properties and operating conditions (air, water, velocity, turbulence models, etc.)

Once boundary conditions are assigned and validated, export the case for meshing.

3. Generate Mesh in tensorHVAC-Pro

Open the prepared case in tensorHVAC-Pro to create the computational mesh.

Mesh preparation inside tensorHVAC-Pro:

• Import the boundary-prepared case from tCFD-Pre

• tensorHVAC-Pro automatically generates the external or internal fluid domain
  → No need to model a separate airflow region in Rhino

• Adjust mesh size and refinement levels based on:

  • Geometry complexity

  • Desired accuracy

  • Target computational time

• Add refinement regions or local mesh inflation if needed for high-gradient areas

After configuration, run the meshing process and review the mesh preview to ensure quality.

4. Solve CFD Simulation and View Results in tensorHVAC-Pro

Once the mesh is validated, you are ready to run the CFD simulation.

In tensorHVAC-Pro you can:

• Launch the solver (steady or transient)

• Monitor convergence of residuals

• Track flow variables such as velocity, pressure, turbulence, and temperature

• Inspect intermediate solution behavior

• Post-process results directly inside the software

Available visualization tools:

• Velocity contours & streamlines

• Pressure distribution

• Temperature fields

• 3D volume rendering

• Plane slices and cut sections

• Vector arrows & pathlines

When the simulation is complete, you can export plots, animations, or data for reporting or further analysis.

Conclusion

With Rhinoceros, tCFD-Pre, and tensorHVAC-Pro, running CFD simulations becomes dramatically more intuitive.
This workflow removes the need for complex negative-domain modeling, simplifies boundary setup, and allows fast meshing and solving—all while maintaining professional engineering accuracy.

Architects, HVAC designers, and engineers can now integrate CFD early in the design process, validate concepts faster, and produce more efficient, data-driven designs.

tensorHVAC-Pro is a dedicated HVAC flow and thermal simulation software, Intuitive and easy to use, designed for HVAC engineers - not CFD expert. Learn more..

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