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March 2019


Sebastian Desand

5 things about wind simulations CFD specialists should know

1. If you’re running RANS, you’re probably doing it wrong

When using computational fluid dynamics (CFD) to measure the urban microclimate, 96% of studies use a RANS model (Reynolds Averaged Navier-Stokes). That’s the conclusion of an article that reviews 183 analyses. However, external flow behaviour is complex and averaged simulations do not reveal everything when analysing wind in urban areas.

2. LES is more!

Large Eddy Simulations are time-dependent simulations capable of capturing the complex behaviour of external flow analyses. For assessing wind in urban areas, LES is more! Ingrid Cloud’s high-fidelity simulations have shown to be 95% as accurate as real-life measurements.

3. Automated mesh generation and refinement are real. Enjoy them!

Ingrid Cloud's automated process applies geometrical heuristics to create an initial mesh, which is then refined only where necessary. This is a unique Ingrid Cloud feature! Guided by a posteriori error estimation in wind load prediction, the adaptive algorithm constructs local error indicators that decide what cells in the mesh must be refined to optimise the mesh.

4. You don’t have to spend hours preparing the geometry for simulations

Ingrid Cloud uses a mesh wrapper to remove imperfections in the geometry (such as intersections and small gaps); in other words, the geometry doesn’t need to be airtight! Default heuristics are used in the wrapper to decrease human error and accelerate the process.

5. HPC resources are more affordable than you think

The amount of computational power required to run a CFD simulation can be expensive or, if you’re running it locally, time-consuming. Ingrid Cloud uses some of the fastest supercomputers in the world to run a high-fidelity simulation in a cloud environment, and prices start at 124 USD per simulation. Moreover, after your simulation is finished, you can download the raw data (e.g. VTU-files) and do additional work with it!



Simulations are conducted in supercomputers with algorithms that produce accurate results.