What´s new in WAsP 11

WAsP 11 includes a fundamentally new approach to Computational Fluid Dynamics (CFD) for wind resource assessment in complex terrain. We call this new feature WAsP CFD and it combines WAsP with the CFD solver EllipSys. The design philosophy of WAsP CFD has been a joint model approach; you set up the WAsP project and can subsequently opt for a CFD solution if the site complexity justifies the added computational effort. WAsP CFD offers the possibility to make wind resource assessments in complex terrain which are:

  • Accurate: EllipSys adapted specifically for flow over terrain and WAsP CFD developed specifically for wind resource assessment
  • Reliable: Reproducible, high quality calculations, applying the Wind Atlas Method
  • Fast: Only a few hours per WAsP CFD calculation
  • Easy: No knowledge about CFD needed
  • Cheap: Low price per WAsP CFD calculation, no hardware investment necessary and no CFD training needed

Other major new features in WAsP 11 are:

  • New Terrain Analysis hierarchy member, to which vector maps are always associated
  • New Generalized Wind Climate (*.gwc) file format replaces the Wind Atlas (*.lib) file format
  • Vertical wind profile model and parameter settings are now part of the Generalized Wind Climate file; A number of model parameters, which in WAsP 10 and earlier versions were saved with the WAsP project, are now saved with the Generalized Wind Climate file
  • Unlimited number of points in WAsP terrain map files
  • A number of features like map-handling and resource-grid calculations have been improved over WAsP 10;
  • A new dongle-free, internet-based licensing system is introduced

And in detail:

The Ellipsys CFD flow model can drive WAsP calculations

  • In earlier versions of WAsP, the vector map hierarchy member was the source of flow corrections. Now the vector map is an input to a new hierarchy member called ‘Terrain Analysis’. Sites look to the terrain analysis for their flow perturbations; the terrain analysis uses the vector map.
  • A terrain analysis appears where previously there would have been a vector map in the hierarchy. Terrain analyses require a vector map as a child.
  • Terrain analyses can be of two types: either “IBZ” or “CFD”. IBZ corresponds exactly to the traditional WAsP flow model which has been in use in earlier versions.
  • Configuration parameters relating to the IBZ flow modelling are no longer handled by the project. The IBZ terrain analysis has parameters which can be edited.
  • CFD terrain analysis calculations use some IBZ model results too, and the relevant IBZ parameters are exposed through the CFD terrain analysis.
  • CFD calculations do not produce RIX values.
  • The CFD model does not distinguish between roughness and orographic corrections: these are displayed in the user interfaces together, labelled as orographic corrections, but are in fact net terrain effect corrections.
  • CFD flow model calculations are performed on a server (not on the computer where WAsP is running). Calculation request files are generated by the WAsP program, saved to disk and then sent to the server from a separate (new) utility program called ‘WAsP CFD Calculation Manager’.
  • CFD Flow model calculation results are returned as files which are imported to the WAsP program to support site assessment calculations.
  • Wind data and site locations are stored on the local machine. Climate calculations are performed locally. Only terrain data and flow corrections are passed to and from the server.
  • CFD tiles are preferably stored in a folder with the workspace name in the same path as the workspace, but you don’t need to keep them there.
  • Note that CFD terrain analysis calculations require a map with roughness information.

‘Wind Atlases’ become ‘Generalised Wind Climates’

  • What were previously called Wind atlases are now called ‘Generalised wind climates’ (GWCs).
  • The climate calculation parameters are no longer stored as project configuration settings. They are now part of the GWC, so each GWC has its own set of parameters which can be separately edited in a new second tab on the GWC window.
  • The set of parameters available depends on the selection of a vertical wind profile model for the GWC.
  • For now, there is only one vertical wind profile model available, called ‘Classic’. This exactly corresponds to the older wind atlas / LIB. There may be more vertical wind profile models in later releases.
  • There is a new (xml) file format with extension *.gwc to store the GWC data. This format includes the parameter values, so that they follow the other data when used in different contexts.
  • When opening projects with old wind atlases, they are assumed to have “classic” profiles. The profile parameters are taken from the host project or, if no host project exists, the defaults are used.

Miscellaneous improvements

  • WAsP 11 does not use a dongle for licence protection. There is a new internet-based system of licence verification. A licence file needs to be registered to licence the installation. The licence file should be sent to you by email as a small attachment. The licence is registered via the main program ‘Help menu’, so the Risø Licence manager program is no longer needed.
  • Reopened resource grids are not immediately loaded with the workspace. They are only loaded from disk when needed by the program. This makes it much faster to open workspaces.
  • You can choose not to save resource grid results to a workspace file. This makes the workspace smaller, and the saving faster, but the results will need to be recalculated next time you open the workspace. This option is available on the resource grid window settings tab.
  • Very large maps are now supported. The effective limit to the map size is undefined. The handling time in the program (opening from file and drawing) will provide the most likely limitation. Please note that it is nevertheless recommended to prepare a map of appropriate size in the map editor before loading it into the WAsP program.
  • Vector map drawing is now faster, the difference is especially noticeable with large maps.
  • A long-standing bug in the IBZ calculation core is fixed. Anomalous roughness information would occasionally cause a crash.

Changes and depreciated features

  • Roughness roses are no longer supported: all roughness information must be provided from map data. On opening an old (pre-WAsP 11) workspace, any roughness rose is automatically converted to a note.
  • Sites without a map location are no longer supported: all sites must have a valid location.
  • Resource grid U and PD outputs are now emergent, not the depreciated “omni-directional” values.
  • Library functionality is removed.
  • The project configuration of parameter values is still editable, but now the terrain analysis is also configuration-editable. The hierarchy icon is updated to indicate if non-default values have been set.
  • Default roughness is properly implemented. If you set the “default background roughness parameter” (on a terrain analysis), this will actually be used for calculations in the absence of any roughness data in the vector map. Note that this only applies to IBZ terrain analyses for now, because the CFD flow model requires a map with roughness information.
  • On opening an old (pre-WAsP 11) workspace, each vector map which is in a project is automatically made a child of an IBZ terrain analysis. The configuration parameters for that IBZ terrain analysis are automatically taken from the saved values for the source parent project.
  • You can still insert a vector map from file, but an IBZ terrain analysis is automatically inserted as its parent by default.
  • All WAsP 10 and older results are marked as dirty when opened in WAsP 11.
  • You cannot open a WAsP 11 workspace in WAsP 10, but there is an export function in WAsP 11 which will save a WAsP 10-compatible workspace. Look on the Tools menu to find it.
  • WAsP 7 version files or workspaces cannot now be imported directly to WAsP 11. We suggest that if you need to do this, you download WAsP 10 and use (unlicensed) it to perform the update on the files.
  • WasP 11 does not provide a tool for automatic update of version 8 scripts. Again, use WAsP 10 if you need this functionality.
24 MARCH 2018