RWIND 2 | Wind Simulation (Wind Tunnel)
Generation of Wind Loads Based on CFD for Any Type of Structure
Great Program RWIND Simulation
"RWIND Simulation - absolutely brilliant!!! CONGRATULATIONS!!!"
Very Successful RWIND Simulation Webinar
"The webinar about RWIND Simulation was very successful!
From now on, it is possible to analyze wind forces on geometries of objects that are not regulated in the standard. The wind force assumption according to the standard was often a more or less good estimate."
"The RFEM add-on module RF-STABILITY is a perfect combination with RWIND Simulation. Using RF-STABILITY, I can perform a buckling analysis to get accurate effective lengths. Using RWIND Simulation, I can get accurate wind loads. For unusually shaped structures, it would be a wild guess if calculating wind loads from the standard code... either not conservative or too conservative. My client is happy with the results and impressed!"
RWIND is a program (digital wind tunnel) for the numerical simulation of wind flows around any building geometries with determination of the wind loads on their surfaces. RWIND is available as a Basic and Pro version.
This program was developed in cooperation with PC-Progress and CFD Support and can be used as a stand-alone application or together with RFEM and RSTAB for a complete structural analysis and design.
Features of RWIND Basic
- Calculation of stationary incompressible turbulent wind flow using the SimpleFOAM solver from the OpenFOAM® software package
- Numerical scheme according to the first and second order
- Turbulence models RAS k-ω and RAS k-ε
- Consideration of surface roughness depending on model zones
- Model design via VTP, STL, OBJ, and IFC files
- Operation via bidirectional interface of RFEM or RSTAB for importing model geometries with standard-based wind loads and exporting wind load cases with probe-based printout report tables
- Intuitive model changes via drag & drop and graphical adjustment assistance
- Generation of a shrink-wrap mesh envelope around the model geometry
- Consideration of environmental objects (buildings, terrain, etc.)
- Height-dependent description of the wind load (wind speed and turbulence intensity)
- Automatic meshing depending on a selected depth of detail
- Consideration of layer meshes near the model surfaces
- Parallelized calculation with optimal utilization of all processor cores of a computer
- Graphical output of the surface results on the model surfaces (surface pressure, Cp coefficients)
- Graphical output of the flow field and vector results (pressure field, velocity field, turbulence – k-ω field, and turbulence – k-ε field, velocity vectors) on Clipper/Slicer planes
- Display of 3D wind flow via animated streamline graphics
- Definition of point and line probes
- Multilingual user interface (German, English, Czech, Spanish, French, Italian, Polish, Portuguese, and Russian)
- Calculations of several models in one batch process
- Generator for creating rotated models to simulate different wind directions
- Optional interruption and continuation of the calculation
- Individual color panel per result graphic
- Display of diagrams with separate output of results on both sides of a surface
- Output of the dimensionless wall distance y+ in the mesh inspector details for the simplified model mesh
- Determination of the shear stress on the model surface from the flow around the model
- Calculation with an alternative convergence criterion (you can select between the residual types pressure or flow resistance in the simulation parameters)
Features of RWIND Pro
- Calculation of transient incompressible turbulent wind flow with the BlueDyMSolver solver
- LES SpalartAllmarasDDES turbulence model
- Consideration of stationary solution as initial state for transient calculation
- Automatic determination of analysis period and time steps
- Use of intermediate results during the calculation
- Organized display of time-varying results via time step units
- Diagram of drag force and point probe results over analysis time
- Display of line probe results for any time steps in a diagram
Input
RFEM and RSTAB have a special interface for exporting models (i.e. structures defined by members and surfaces) to RWIND Basic. In this interface, the wind directions to be analyzed are defined by means of related angular positions about the vertical model axis, and the height-dependent wind and turbulence intensity profile is defined on the basis of a wind standard. Based on this information, you can use stored calculation parameters for a stationary calculation for each angular position.
You can also run the RWIND Basic program manually without the interface in RFEM and RSTAB. In this case, the structures and terrain environment in RWIND Basic are directly modeled by importing VTP, STL, OBJ, and IFC files. The height-dependent wind load and other fluid-mechanical data can be defined directly in RWIND Basic.
Calculation
RWIND Basic uses a numerical CFD model (Computational Fluid Dynamics) to simulate wind flows around objects using a digital wind tunnel. The simulation process determines specific wind loads on the model surfaces from the flow result around the model.
A 3D volume mesh is used for the simulation. RWIND Basic performs an automatic meshing on the basis of freely definable control parameters. For the calculation of wind flows, RWIND Basic provides a stationary solver, while RWIND Pro provides a transient solver for incompressible turbulent flows. Surface pressures resulting from the flow results are extrapolated onto the model for each time step.
Output
The solution of the numerical flow problem gives results on and around the model:
- Pressure on structure surface
- Coefficient Cp distribution on the structure surfaces
- Pressure field about structure geometry
- Velocity field about structure geometry
- Turbulence k-ω field about structure geometry
- Turbulence k-ε field about structure geometry
- Velocity vectors about structure geometry
- Streamlines about structure geometry
- Forces on member-shaped structures that were originally generated from member elements
- Convergence diagram
- Direction and size of the flow resistance of the defined structures
These results are displayed in the RWIND environment and evaluated graphically for freely definable zones. Since voluminously displayed flow results about the structure geometry are confusing, RWIND Basic provides freely movable section planes for the separate display of the "solid results" in a plane. In addition to a static display, there is also an animated display in the form of moving line segments or particles for the 3D branched streamline result. This option helps to represent the wind flow as a dynamic effect.
All results can be exported as an image or, especially for the animated results, as a video.
Transfer of Wind Loads to RFEM or RSTAB
When you start the analysis in the application of RFEM or RSTAB, a batch process starts that places all member, surface, and solid definitions of the model rotated with all relevant coefficients in the numerical wind tunnel of RWIND Basic, starts the CFD analysis, and returns the resulting surface pressures for a selected time step as FE mesh nodal loads or member loads into the respective load cases of RFEM or RSTAB.
These load cases which contain RWIND Basic loads can be calculated and combined with other loads in load combinations and result combinations.
Disclaimer:
This offer is neither approved nor endorsed by OpenCFD Limited, producer and distributor of the OpenFOAM software via www.openfoam.com and the owner of the OPENFOAM® and OpenCFD® trade marks.
Further Information
Manuals
Advantages
- Consideration of adjacent buildings and other objects
- Wind load application on complex or irregular structures not addressed in design standards
- Ability to close structural openings for wind simulation such as windows or doors
- Wind load application, a calculation of anchorages for photovoltaic systems
- Consideration of internal pressure due to wind flow through structural openings
- Wind analysis tool for structure modifications during the preliminary design process
Book About CFD
The following book presents a comprehensive perspective on CFD with the finite volume method, as implemented in RWIND default solver OpenFOAM.
Dlubal is Member of WtG
Dlubal Software is a member of the Windtechnological Society
Price
Wind Comfort in Pedestrian Areas and Around Buildings
Buildings are structures surrounded by wind. The flow around them creates specific loads on the surfaces, which are to be used for the design in structural analysis.

The stand-alone program RWIND 2 for the numerical simulation of wind flow is available as a Basic and Pro version. RWIND Pro allows the calculation of transient incompressible turbulent wind flows (in addition to the stationary ones in RWIND Basic).
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