## Search found 51 matches

Tue Feb 09, 2021 2:55 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
1. Is it possible to obtain the aerodynamic load acting in the fore-aft and side-side direction using FAST if I disable TwrAero?
2. Does RtAeroFxh , RtAeroMxh represents normal and tangential forces?
Mon Feb 08, 2021 9:28 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
Thank you for the clarification. TwrAero was disabled previously.

Does FAST Calculate the normal and tangential thrust forces due to wind?

Akheel kk
Sun Feb 07, 2021 10:05 pm
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
I have run a case with TwrNβFdx with β ranging from 1 to 9. but the output corresponding to these variable were obtained as zero. Can you comment on this?

Sincerely,
Akheel kk
Tue Feb 02, 2021 9:19 pm
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
I was asking that if I summate the aerodynamic force at all tower node, Will I get the total (integrated) aerodynamic force acting on the tower?
Mon Feb 01, 2021 10:29 pm
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
This message is regarding aerodynamic force calculation on tower. Does it make huge difference if I summate the aerodynamic loads on tower node from that with integrated force?
Wed Jan 27, 2021 8:56 pm
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
Is it possible to get time series of forces - thrust and moment due to wind on the tower and platform, wave forces on platform - acting on the structure due to wave and wind loads for OC3 Spar using FAST? If yes, In which module do I need to set the output channels?

Thu Jan 21, 2021 9:17 am
Forum: Computer-Aided Engineering Software Tools
Topic: Question about using TMD in nacelle
Replies: 18
Views: 2513

### Re: Question about using TMD in nacelle

Dear Sir, Q1 . I have simulated a case with wave and wind loads acting on the structure. With the same loading condition another test was run with TMD(x) in the nacelle. But the response in fore-aft direction was not reduced and the response in surge was found to increase considerably, which was not...
Wed Dec 16, 2020 3:17 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
What I expected was a sectional geometry at different section of the platform just like Table 2.1 of "Definition of a 5-MW Reference Wind Turbine for Offshore System Development".

Mon Dec 14, 2020 11:39 pm
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
How can I get information about the geometric details of OC3 spar. In fact what I meant is the geometric distribution along the depth of the platform.

Thu Nov 26, 2020 7:19 pm
Forum: General
Topic: openfast v2.3
Replies: 20
Views: 2742

### Re: openfast v2.3

Dear Sir,
Regardiung (2), I meant that if I see similar behavior (shift in mean position) for any dof (not necessarily Heave) under wind and wave, Will it be due to increased draft?
Mon Nov 23, 2020 4:00 am
Forum: General
Topic: openfast v2.3
Replies: 20
Views: 2742

### Re: openfast v2.3

Dear Sir, I have simulated a free vibration case with initial fore-aft displacement 10m. Then I incorporated a TMD into it. I could observe that the TMD vibration was shifted. Attached a plot for better understanding. 1. What could be the probable reason for it. 2. What do I need to infer if similar...
Sun Nov 22, 2020 3:04 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
Attached is the plot of PSD for different responses. The axis were set same as in the figure 49. What would be the probable reason for mismatch between the plots?
Thu Nov 19, 2020 11:11 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir, Thank you for the quick response. I did the simulation of load case 5.3. I used the time series in fore aft response in the script Jason_PSD.m expecting that I would get a plot similar to Figure 49 of the report. That I obtained now was a horizontal line (when x and y axis are arranged as ...
Thu Nov 19, 2020 10:53 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir, This is regarding the Jason_PSD.m. I imported the table, coded the time series as 'Data' and entered df. then I used the command [ f, S1 ] = Jason_PSD( Data, df ); The results seems to be same as the fft output (A vertical line close to the y-axis). What modifications do I need to make to ...
Thu Nov 19, 2020 10:39 am
Forum: Structural Analysis
Topic: NREL 5MW OC3-Hywind (Test 24) Questions
Replies: 78
Views: 13517

### Re: NREL 5MW OC3-Hywind (Test 24) Questions

Dear Sir,
How does OpenFAST distinguish between JONSWAP and PM Spectrum? Setting WaveMode = 2 is common for JONSWAP and PM Spectrum. Is there any other parameter which needs to be adjusted depending on spectrum used?