Computational fluid dynamics (CFD) simulations are powerful tools for analyzing fluid flows in a wide range of applications, from aerospace engineering to climate science. However, achieving accurate results requires overcoming several challenges.
These include ensuring the following:
(1) Well-Defined Boundary Conditions:
The reason for the difficulty in solving the underlying PDEs may be due to ill-defined or non-unique boundary conditions. It is crucial that the boundary conditions provide unique solutions for different values.
(2) Proper Time Step in Avoiding Numerical Instability in Transient Simulations:
When performing transient simulations, the time step should be appropriately chosen to prevent the Courant’s number from becoming too large. If this number blows up, it may lead to numerical instability and inaccurate results.
(3) Good Mesh Resolution:
In particular, for Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS), it is essential to ensure that the mesh is fine enough to resolve the size of the eddies accurately. If the mesh is too coarse, it may not capture the important features of the flow accurately, leading to incorrect predictions.
