It Starts with the Physics: Choosing the Right Turbulence Model and Solver Settings

This is ground zero. Choosing the wrong turbulence model is like using a sledgehammer for brain surgery. For example, using a standard k-epsilon model for a flow with strong swirl or curvature can completely misrepresent the flow separation, leading you to a flawed design.

We always start by discussing the flow regime. Is it transitional? Fully turbulent? Is there significant wall interaction? This determines if we should be using a k-omega SST model to better capture near-wall effects or even considering a more computationally intensive LES approach for transient phenomena. The choice dictates the validity of everything that follows.

The Art of the Mesh: Why We Prioritize Hexahedral Meshing for Unmatched Accuracy

The mesh is the canvas for the simulation. A poor, automatically-generated tetrahedral mesh can introduce so much numerical diffusion that the results are smeared and inaccurate, even if the physics models are correct. It’s a common shortcut, and a dangerous one.

Where possible, we build structured, hexahedral meshes. Why? They align with the flow direction, require fewer cells for the same level of accuracy, and drastically reduce numerical error. A few years ago, we worked on a centrifugal pump impeller where an initial tetra mesh showed no cavitation. The results seemed fine. But our experience made us suspicious. We spent the extra time to build a high-quality hex mesh. The new simulation correctly predicted cavitation inception right where the client later saw it happen in testing. That experience taught us that a good mesh isn’t an option; it’s a requirement.

The Non-Negotiable Step: Grid Independence Study and Results Validation

How do you know if your mesh is fine enough? You don’t, unless you test it. This is a step many providers skip because it’s time-consuming. We don’t. A Grid Independence Study is the bedrock of our process. We run the simulation on progressively finer meshes until the key results (like pressure drop or lift coefficient) stop changing significantly. Only then can we be confident that the solution is independent of the mesh resolution.

And once we have a solution, we validate it. We compare our results against established experimental data or published research papers. This ensures the entire simulation—physics, mesh, and all—accurately represents reality. This is absolutely critical in many of our projects, especially those that are part of our broader CFD Thermal Analysis Services. It’s your ultimate assurance that the numbers we provide are not just plausible, but defensible.

Our Collaborative 4-Step Process: From Your Problem to a Validated Solution

There’s no black box here. We believe in total transparency so you’re always in control and aware of the project’s status. It’s a partnership, and it generally follows this path:

1. Discovery & NDA: We start with a technical deep-dive call. This is for us to understand your engineering problem and for you to vet our expertise. Before any sensitive files are exchanged, we sign a comprehensive Non-Disclosure Agreement. Your intellectual property is paramount.
2. Simulation Setup: This is where the heavy lifting begins. We handle CAD cleanup, build a high-fidelity mesh (often structured hex meshes, as mentioned), and meticulously define the physics, boundary conditions, and solver settings based on the problem’s unique requirements.
3. Execution & Analysis: We run the simulations on our dedicated hardware. But we don’t just hit ‘solve’ and walk away. We monitor convergence, analyze interim results, and perform the critical grid independence studies and validation checks.
4. Reporting & Debrief: You receive a full technical report—not just a data file. It details the methodology, assumptions, results, and our engineering conclusions. We then schedule a final call to walk you through the findings and discuss next steps.