Search found 22 matches

by Salem.Okpokparoro
Tue Mar 03, 2020 3:08 pm
Forum: Computer-Aided Engineering Software Tools
Topic: About WAMIT model for 5MW OC3 Hywind
Replies: 10
Views: 4348

Re: About WAMIT model for 5MW OC3 Hywind

Dear Jason
Many thanks.

Regards
by Salem.Okpokparoro
Tue Mar 03, 2020 2:03 pm
Forum: Computer-Aided Engineering Software Tools
Topic: About WAMIT model for 5MW OC3 Hywind
Replies: 10
Views: 4348

Re: About WAMIT model for 5MW OC3 Hywind

Dear Yu, The same WAMIT input file will generate both the *.out and *.1, *.3, and *.hst files. You can use the same WAMIT input file for both HydroDyn and OrcaFlex. Best regards, Dear Jason I do not have access to WAMIT but require the OC3 spar *.out file for Orcaflex. The *.1, *.3, and *.hst files...
by Salem.Okpokparoro
Sat Feb 29, 2020 2:08 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason Same errors occur when simulating dlc1. 6a with lesser tower drag. How can I simulate conditions with Hs>=10m for the spar? When i reduce the Hs to <9m the simulations run smoothly. But these are less than the 50yrs Hs of the reference site. Although these large waves induce large platfor...
by Salem.Okpokparoro
Sat Feb 01, 2020 1:38 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason
The responses for DLC6.x are attached. The simulation still goes unstable even when the yaw stiffness is increased by x1000.
Regards
by Salem.Okpokparoro
Fri Jan 31, 2020 9:40 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason I am still unable to run simulations with extreme sea state either Dlc1. 6 or 6. x. For the latter the idling condition has been set up : blades feathered at 90deg, aerodyn setting set as you've indicated on several posts, pcmode disabled. The simulations go unstable with the sea state de...
by Salem.Okpokparoro
Fri Jan 31, 2020 7:22 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason I am still unable to simulate 50 years extreme conditions of Uref 51m/s, Hs=13m and Tp=14s for the OC3-Hywind. The simulation keeps getting numerically unstable with the Small angle assumption violated in SUBROUTINE SmllRotTrans() due to a large platform displacement. Setting PtfmPDOF= Fa...
by Salem.Okpokparoro
Sat Nov 23, 2019 3:41 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason
Dropping the time step to 0.01 s didn't resolve the problem. These huge waves physically makes sense, I'd appreciate any more suggestions s to how OpenFAST can run smoothly at these conditions.
Regards
by Salem.Okpokparoro
Fri Nov 22, 2019 11:39 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason I ran two simulations, with yaw stiffness of 98340000Nm/rad and 9834000000Nm/rad. I've attached the results. The platform appears to be stiff in the yaw DOF as expected, yet the simulation still aborts. FASTout2.png I have also attached simulation with PtfmYaw DOF= FALSE: FAST3.png Lookin...
by Salem.Okpokparoro
Thu Nov 21, 2019 6:42 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason
I increased the yaw stiffness by x10 and x100 but the same error occurs at the same time step.
Regards
Salem
by Salem.Okpokparoro
Thu Nov 21, 2019 5:24 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason
Pardon my trivial question, but do i increase it by any arbitrary magnitude?
by Salem.Okpokparoro
Thu Nov 21, 2019 1:39 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason Yes the simulation runs smoothly when I set Yaw DOF=False. I have not modified the default OC3-Hywind spar model yaw stiffness which I take it is included in the accompanying WAMIT .hst files. See below the hydrodyn input file: ------- HydroDyn v2.03.* Input File -------------------------...
by Salem.Okpokparoro
Wed Nov 20, 2019 12:14 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

FASTout.png These are the results. The error messages are: ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Time: 150 of 3660 seconds. Estimated final completion at 12:36:2...
by Salem.Okpokparoro
Wed Nov 20, 2019 5:38 am
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason I have looked at several post and tried the suggestions given. I have reduced the time step to 0.00125 and 0.0001 yet the instability still occurs. I have set new ICs as well still no difference. However, I have found that when I disable platform pitch DOF all the simulations run smoothly...
by Salem.Okpokparoro
Fri Nov 15, 2019 1:55 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Simulating the parked turbine
Replies: 47
Views: 6623

Re: Simulating the parked turbine

Dear Jason I am encountering similar problem with simulation of IEC DLC1.6a of the OC3-Hywind. The wind speed 4m/s:2m/s:24m/s; Hs=13m, Tp=14s. Total simulation length is 3600s. Some realizations run without any errors, however a handful produce some errors as listed below: 1) Warning: SkewedWakeCorr...
by Salem.Okpokparoro
Thu May 30, 2019 9:08 am
Forum: Structural Analysis
Topic: OC3-hywind tower forces
Replies: 14
Views: 3065

Re: OC3-hywind tower forces

Dear Jason I would greatly appreciate clarity on certain issues concerning wind loads on the tower. My aim is to isolate the wind forces on the tower and apply them based on "Eurocode 1. Action on structures, part 1-4: Wind load" to my 3d FE model of the tower. The following are the approa...

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