RWIND 2 | Wind Simulation (Wind Tunnel)

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, and so on)
• 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, Russian, and Chinese)
• 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
• Freely adjustable wind permeability for surfaces (Go to Product Feature)

Input

To model structures in RWIND Basic, you find a special application in RFEM and RSTAB. Here, you define the wind directions to be analyzed by means of related angular positions about the vertical model axis. At the same time, you define the elevation-dependent wind profile on the basis of a wind standard. In addition to these specifications, you can use the stored calculation parameters to determine your own load cases for a stationary calculation per each angular position.

As an alternative, you can also use the RWIND Basic program manually, without the interface application in RFEM or RSTAB. In this case, RWIND Basic models the structures and terrain environment directly from the imported VTP, STL, OBJ, and IFC files. You can define the height-dependent wind load and other fluid-mechanical data directly in RWIND Basic.

Calculation

RWIND Basic uses a numerical CFD model (Computational Fluid Dynamics) to simulate wind flows around your objects using a digital wind tunnel. The simulation process determines specific wind loads acting on your model surfaces from the flow result around the model.

A 3D volume mesh is responsible for the simulation itself. For this, RWIND Basic performs an automatic meshing on the basis of freely definable control parameters. For the calculation of wind flows, RWIND Basic provides you with a stationary solve and 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

By solving the numerical flow problem, you can obtain the following results on and around the model:

• Pressure on structure surface
• Coefficient Cp distribution on the structure surfaces
• Pressure field about the structure geometry
• Velocity field about the structure geometry
• Turbulence k-ω field about the structure geometry
• Turbulence k-ε field about the structure geometry
• Velocity vectors about the structure geometry
• Streamlines about the 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

Despite this amount of information, RWIND 2 remains clearly arranged, as is typical for the Dlubal programs. You can specify freely definable zones for a graphic evaluation. Voluminously displayed flow results about the structure geometry are often confusing – you know the problem for sure. That's why RWIND Basic provides freely movable section planes for the separate display of the "solid results" in a plane. For the 3D branched streamline result, you have an option to select between a static and an animated display in the form of moving line segments or particles. This option helps you to represent the wind flow as a dynamic effect.

You can export all results as a picture or, especially for the animated results, as a video.