HPJ

Hi, I'm trying to find information about the actual implementation of the PARK model in WAsP. The documentation I have so far been able to find only describes how to calculate the velocity deficit for a single wake. That is using the free-stream velocity as input to the deficit calculation. This is shown on page 5 (dV01) in this presentation: http://www.risoe.dk/vea/storpark/presentations/WAsP8%20Wake-effect%20model.pdf. Another expression is also shown (dV12). It is unclear what U1 and V1 represents? Is any "cascading" effects accounted for? That is, is the model initiated with a free-stream velocity at the most upstream turbine and then the velocities used in the deficit calculation reduced with the wake effects down the 'rows'? Are any speed-up effects accounted for? And if so, how? I guess what I'm looking for is a more in-depth explanation of the implementation in WAsP. Thank you as always! -HP

Hi, I was wondering how the slope grids are calculated in WEng? I can understand how the terrain inclination grid is done, but the slope grids I can't figure out. Thanks! - Hans Peter

Hi, I've heard that the scripting has changed quite a bit from WEng 2 to WEng 3. Are there any plans to release a new version of the scripting documentation (or will I have to learn from looking at the supplied scripts)? Thanks - Hans Peter

Hi Morten, Thanks for the quick answer! I definately know the problem of having to hurry :-) I've sent a request to the weng support email. Thanks again. - HP

Hi, I've been trying to implement the terrain-fitting algorithm in: "Wind and wake models for IEC 61400-1 site assessment" (can also be found in the help file of WAT). I am, however, unable to get any sort of reasonable result. I just wanted to doublecheck that the formulas listed in the help-file are accurate? Thanks - Hans Peter

Thanks Duncan. There's no question this will come in handy at some point, but... I should, of course, have specified in more detail, the grids I was thinking of. I was hoping to export the wind grid maps from WEng. That is, for instance, the friction velociy grid or the terrain inclination grid. If I can't export them as images, perhaps they can be exported as grid files in some 'easy' way ;-) Thanks again, Hans Peter

Hi, is there any way of saving the grids as pictures for inclusion into reports via scripting? I can of course do it manually, but that's quite cumbersome and time consuming. Let me know. - Hans Peter

Hi I've made a script for WEng that provides me with speed and TI for each turbine/sector/height that has been specified in the workspace. However... After some time it stalls. I've tried reducing the resolution and after reducing it enough the script runs to the end. What's going on? It seems like it's either a calculation issue or a memory issue? I'll happily send the script so you can check it. - Hans Peter

Hi Duncan, Thanks for the quick turn-around! It is exactly the climate I need; AEP isn't required. So I think the method of just iterating through all met stations and getting the backprediction will be perfect. I'll see if I can figure out a way to actually do this in a script. If I can't, I'll let you know that help is required ;-) Thanks again. - Hans Peter

It can be found here: http://www.risoe.dtu.dk/da/knowledge_base/publications/reports/ris-r-1068.aspx?sc_lang=en - HP

Hi Duncan, Thanks for the answer. Unfortunately I do, in fact, need to take into account more than one atlas. At least for most cases. Normally I would run one wind farm with several site groups under it. The site groups are only based on the met masts, so for each different met mast, I would have a site group under the wind farm. Re-doing calculations for each met mast wouldn't normally be a problem as the extra time to do this isn't critical. Hopefully that makes it easier to insert and delete the site? Let me know what you come up with. Thanks. - Hans Peter

Hi, I have a script that currently exports information on the turbines under a site group. I, however, also need the same information about the met mast locations. I would therefore like to, in my script, place a turbine on the mast location with the hh of the measurements in the tab file. Then recalculate and export the information. And finally delete the turbine. Is there anyway this is possible. I can't seem to get my head around the Wasp interfaces and methods. Thanks. - Hans Peter

Duncan, I would definately be interested in having a look at the new version. Unfortunately I can't spare the time for an in-depth look, so a stand-alone exe would be very interesting! Let me know. - Hans Peter

Thanks Duncan. I'll try tinkering with it. If you're finally adding Wasp tp the documentation, please don't worry about anything I write in here; just keep at the documentation ;-) Thanks again.

Hi, unfortunately I don't have the time to figure this out right now, but I really need a small script that sets the project air density to whatever the most top-level wtg selected table is using. It's a pain having to change the project air density to match the power curve as it is always the power curve that is correct. Is the project density used for anything?