15. Creating flow fields
Flow fields are intended to provide all room points of a scenery with location-specific updraft conditions, as they are required, e.g. to display slope soaring sceneries.
To do so, one or several guidance planes are defined in vertical upright direction and running in wind direction. Several guidelines are created on each guidance plane which will determine the air flow progress on this layer. Finally, the RSK can create a flow field image resulting of the progression of the guidelines where the color values will determine the force of the updraft at the corresponding pixel position. In this case, green is showing the updraft, red is showing the downdraft and yellow is showing the horizontal flow.
The following illustrations shows a 3-dimensional view of the scenery „Rotes Kliff (Kampen Sylt)“ with its three guidance planes. The guidelines as well as the flow field images which are projected on the guidance planes are visible:
Flow fields are defined on the Flow field tab in the Scenery data window:
In order to define flow fields, please proceed as follows:
- Define the optimal wind direction (vertical to the slope) using the Standard wind input field on the Location tab in the Scenery data window.
- Create a new point where a new guidance plane will run through.
- Select the new point and click the Insert plane at selected point button on the Flow field tab.
- Define the final dimensions of the guidance plane in the 3D view by dragging the frames or corners of the new guidance plane while holding the left mouse button pressed. The bottom frame of the guidance plane needs to run along below the constructed ground over the whole length. Drag the remaining sides until all designated updraft zones are being covered.
- Now create the guidelines for the new guidance plane. To do so, select the guidance plane and add at least three new points as support points for the new guideline in the 3D view. Thereby, one point always needs to be located at the left margin and another one needs to be located at the right margin of the guidance plane. When you have entered all points for the new guideline, click on Define new line and after that on all points one after another which are designated for the guideline. Start with clicking on the point located on the margin of the guidance plane which is facing the wind. Finish the definition of the guideline by unchecking the box Define new lines. Create at least three guidelines. One line needs to run shortly above the ground and another one needs to run exactly at the top margin of the guidance plane. Inbetween those two lines you can define as many guidelines as the required updraft profile needs.
- Effected by the different pitches and heights you might require different updraft profiles along the edge of the slope. In this case, please use the Duplicate planes function in order to duplicate the selected guidance plane including any guidelines. To do so, firstly shift the new guidance plane along the slope edge with the help of the mouse wheel and fix it using the left mouse button. Then, modify the duplicated guidance plane as required by shifting the support points as well as by deleting and inserting new guidelines.
- Enter the required resolution at which the flow field images need to be calculated into the Flow field resolution input box. Example: Using a size of 300x100 meters for the guidance plane, and a flow field resolution of 0.5 m/pixel would create flow field images with a size of 600x200 pixels.
- Click on Generate flow field in order to get a flow field image of the selected guidance plane calculated by the RSK. If no guidance plane is selected, the flow field images of all guidance planes are being generated. Depending on the selected flow field resolution, this process might take a few minutes. The flow field images are saved in the project directory and are provided with the name <Projektname>_E0.bmp (Project name_E0.bmp) for the first guidance plane, <Projektname>_E1.bmp (Project name_E1.bmp) for the second guidance plane, etc. For reasons of compatibility, the flow field images are also saved using the name E0.bmp, E1.bmp etc.
- Thoroughly test the updraft profile and optimize the number and the progress of the guideline, if necessary. After modifying any guideline, the corresponding flow field image needs to be regenerated. During the optimization phase you can temporarily accelerate the generating of flow field images by entering a higher value in the Flow field resolution input box.
Following topic: Delivery of the design