18. NBQ Tutorial

CROCO-NBQ kernel solves the compressible and non-hydrostatic Navier-Stokes equations. This kernel can be used to simulate complex nonlinear, nonhydrostatic physics in a realistic but computationally-affordable configuration. Non-hydrostatic effects become important when the horizontal and vertical scales of motion are similar. In oneanic models this typically arises with horizontal scales of the order of 1 km resolved with grid intervals of order 100 m. For motions of larger scale that are resolved with grid intervals of order 1 km, the hydrostatic approximation is well satisfied.

Accurate simulation of nonhydrostatic effects requires to resolve very small horizontal scales. The explicit representation of fine-scale turbulent processes requires a significant number of fundamental numerical choices, such as adapted advective schemes, adaptaed parametrizations, adapted boundary conditions … In the sections you will find some recommendations about the most adapted numerical schemes for Large-Eddy Simulations (LES).

• 18.1. Some important points about Large-Eddy Simulations (LES)
• 18.2. KH_INST Test Case
• 18.3. Set up your own NBQ configuration
• 18.4. NBQ OPTIONS
• 18.5. Appendix : some words on CROCO-NBQ kernel

Related CPP options (for users):

NBQ	Solving the compressible and non-hydrostatic Navier-Stokes equations