nekRS
26.0
Quickstart
Before You Begin…
Installing NekRS
Acquiring the Code
Building NekRS
Setting the Environment
Running your first simulation
Scripts
Visualization
Problem Setup
Case files
Parameter File (.par)
User Sections
General Parameters
OCCA Parameters
Problem Type Parameters
Mesh Parameters
Field Settings
CVODE Parameters
NekNek Parameters
User-Defined Host File (.udf)
OKL block
UDF_Setup0
UDF_LoadKernels
UDF_Setup
UDF_ExecuteStep
Legacy Nek5000 User File (.usr)
Legacy Data Interface
Mesh File (.re2)
NekNek Session File (.sess)
Trigger File (nekrs.upd)
NekRS Files & Extensions
Boundary conditions
Basic boundary conditions
Zero-value BC
User-value BC
Internal / periodic BC
Special cases
NekNek coupling
Turbulent inflow
Velocity recycling
Stabilized outflow [Dong]
Initial conditions
Specification in
.udf
File
Restarting from Field File(s)
Legacy
useric
in
.usr
File
Physical properties
Constant Properties
Variable Properties
Conjugate Heat Transfer
Models and Source Terms
Turbulence models
Large Eddy Simulation (LES)
RANS models
Low-Mach Compressible Model
Custom Source Terms
Momentum Equation
Scalar Equations
Mesh & Meshing
Runtime Setup
Coordinates Modification
Sidesets & Boundary Tags
Connectivity
Nek5000 Meshing Tools
genbox
n2to3
reatore2
Convert External Meshes
Gmsh (
gmsh2nek
)
Exodus II (
exo2nek
)
Tet-to-Hex
Moving Mesh
Conjugate Heat Transfer
h
-Refinement
Miscellaneous Tips
Postprocessing
Checkpointing & Visualization
Adding Custom Fields
Adding Custom Output File
Element Filter
Compute Derived Quantity
Array Operators
Spatial Derivatives
Spatial Integrals
Strain & Rotation Rate
Aero-Forces
Q criterion
Averaging
Time Averaging
Time Averaging (Legacy Mode)
Planar Averaging
ADIOS2 Format (.bp/)
Data Extraction
Insitu Visualization
Legacy Support (userchk)
Running
Native Running
MPI launch scripts
Running on HPC Systems
Runtime Control with Signals
Debugging Tips
Just-in-time Compilation
Verbose and Debug Mode
Check Device Arrays
Kernel in Serial Mode
Synchronization
Using
gdb
Attaching to a Process
Attach Mode
Launch NekRS under
gdb
Tutorials
Fully Developed Laminar Flow
Before You Begin
Mesh Generation
Control parameters file (.par)
User-Defined Host Functions File (.udf)
Loading user parameters
Initial Conditions
Boundary Conditions
Execute Step Routine
Running the case
Post-processing the results
Conjugate Heat Transfer
Governing Equations and Thermo-fluid Properties
Geometry and Boundary Conditions
Mesh Generation
Control Parameters (.par file)
User-Defined Host Functions File (.udf)
Loading User Parameters
Initializations
Custom Buoyancy Source
Boundary Conditions and Buoyancy Force (okl block)
UDF_ExecuteStep
Compilation and Running
Results
RANS Channel
Before You Begin
Mesh and Boundary Conditions
Control Parameters (.par file)
User-defined Host Functions File (.udf file)
Diffusion and Source terms
Mesh Modification
Initial Conditions
RANS Setup
Boundary Conditions
Execute Step Routine
Compilation and Running
Results
Optional: Post-processing Routines
Data Extraction Along a Line
Compute Friction Velocity
Developer guide
Doxygen
Contributing
How to contribute
Theory
Computational Approach
Incompressible Navier-Stokes Equations
Non-Dimensional Navier-Stokes
Stokes Flow
Energy Equation
Non-Dimensional Energy / Passive Scalar Equation
Low-Mach Compressible Flow Equations
Low-Mach Equations with Ideal Gas Assumption
RANS Models
Other Resources
OCCA Memory
Mesh Class (
mesh_t
)
Linear Algebra Functions (linAlg)
SEM Operators (opSEM)
Building the Nek5000 Tools
Glossary
References
nekRS
Developer guide
Doxygen
View page source
Doxygen
The Doxygen pages can be found
here
.