Re: Appendages in resistance calcs

DELFTship forum Hull modeling Appendages in resistance calcs Re: Appendages in resistance calcs


Hi Marven.

I guess I must’ve misunderstood “waves” vs. static/still water. So, is this more about plunging and emerging from flat water that doesn’t respond the the ship’s presence? I should have looked closer at the animation on the web page to note the absense of disturbed, choppy, seas-like water.

As for frame-by-frame or non-dynamic presentation, i’m fine with that, as it seems to be less resources-intensive.

As to DELFT series numbers not being suitable for vessels of 500 feet, how unsuitable? Marketly/drastically, or on the order of 10% mis-calculation/underestimation of resistance? Currently, i get ~7,100 KN resistance for my hull, and if i recall correctly, that isn’t too far off of from a student paper regarding a stretched 5415 hull model taking the DDG-51 out to some 540 feet LPP/LBP. If i private send you my model would you like to use it for internal comparisons? I haven’t auto-faired it because i want to retain certain curves, and it’s not fully-marinized because my skeg is not quited right, and my sonar dome is just a place holder since any given navy would shape it according to the chosen sonar suite.

Roughly, my model is 177m LPP, 21m beam at waterline, cb ~.48 at 6m draft, and cb around ~.53 or so around 7.1.

Marven/Martjin, I don’t know how to profusely thank you/your team for the features and pricing. Now that i’ve figured out that i can import IGES models of my engine and shaftlines i can vastly easier fine-tune my hull earlier in the fairing process. I failed to appreciate it when it was possible in Free 3.x to export/import IGES. I guess i can try to continue helping by way of constant use and periodic feedback.

I hope I didn’t split the thread too many ways…