Obtaining heeled waterlines in Freeship

simple as pressing the Alt key to get those flowlines in but getting old i guess
here, -and hope jeff has enough terrabytes- the freeship 2.6 manual (again?) delftship manual is fatter and can be downloaded from delftship
look at page 39 for flowlines, almost fluid dynamics, gave it a try under heel but dont work in 5 min and probably wont, pitty, back to study the rest

 

Well, playing with it this morning I was able to get everything I was looking for...even flow lines. The hydrostatics adjusted themselves with the angle of heel too. All I did was turn on faces, selected all and mirrored, making sure that the little box that says connect to existing points is checked and voila...a sealed hull that can be tilted at will. Don't be confused by the body plan view...this will show what looks like two hulls...it is only the view from one end on one side and the other end on the other side...I thought I had messed up for a moment before I realized what I did. Tried it first on a symmetrical hull then something a little more like a cat boat hull...worked fine both ways

Here is the assym one:



Oh...if you have other layers that are deselected so you can see the waterlines...make sure when you rotate it that you check the little box about including points that are shared or you will lose some of your hull...or else rotate with everything visible then deselect your excess layers.

 

knew its a tough puppy from delft and good to see succes beyond the manual
your not saying you got the flowlines flowing a heeled flow too do you ?

 

would you explain what flow lines are please.

Now for kicks I think you can rotate 180 and get the rear view heeled .
I also tried to rotate 90 and fool the program a little , it did not work .
but I am thinking that it might work with a section of the mid ship .
make the section 6" thick for start , heel, then rotate 90 , set left edge to 0
and add buttock lines . Probable only work for balanced DE hulls

 

Yes...got flow lines because you can only get the lines to work below the waterline...so anywhere on the hull that is submerged will be able to display flow lines. You can get rear view heeled by using the perspective window and rotating the hull to the correct position...it is almost there in the upper left window in the above screen capture.

Flow lines are the lines the water will supposedly take as it flows across the hull...not counting for leeway or any other effect...so useful in only a small way but useful still. Heeled buttock lines might give a better indication (yes they are available too, along with heeled everything else).

 

Great tool for the visualisation of heeled waterlines!
Too bad that Freeship goes nuts when you ask him to calculate the hydrostatics the hull heeled like that...

 

Where does it go nuts and please explain why it is nuts. I am especially curious about the negatives...for instance the entrance angle.

Here are the heeled hydros:

and here are the unheeled hydros:

And finally the unadulterated unmirrored unheeled hull specs:

 

Looking at them I can state that the unmirrored original hull's weight numbers are half what the mirrored hull's are...because the panels' surfaces are doubled...code error. If you halved the weight of the panel material it might just give the correct #s. Notice the COG Z did shift between the heeled hull and the unheeled hull. I will have to play with this a bit more to see if I can get around the obstacles. At a glance I see 3 problems with negative numbers...one of which, the entrance angle, has me baffled. Once mirrored the entrance angle goes to negative numbers but I can't figure out why.

 

Got better results by assigning each of the panels on the mirrored side to new layers, then excluding the layers from the hydrostatics but leaving the Symmetrical on. All numbers are back in on the positive side and in reasonable ranges. I halved the weights for each panel so the CGs should come out right too.

Here is the heeled version with the extra layers

 

Notice the displacement went up... so to get an accurate reflection of the heeled hull...you would need to reduce the draft to get it back to the correct displacement...which would change your numbers significantly.

Here the draft was reduced from .75 feet to .596 to obtain the same displacement. Compare the numbers to the original unadulterated hull whilst I go beddy bye. I have to work in 4.5 hours. (they are pretty darn close IMHO)!

 

Well, you've asked a question and you gave the answer immediately afterwards.
That's why I said that he FS goes nuts with heeled hull hydrostatics.
I hope Viktor is reading this thread, he can probably figure out why does it behave in such way...
I will PM him and ask if can take a look at that stuff. Though I'm aware that he is doing it for free (in his spare time?), so we cannot pretend an immediate reply...

 

If freeships works on half hull measurements then the position of the cob is going to throw it off if not over the center line . btw when rotating the boat what is the location of the axis?

frank

 

0 on location of axis and Freeship only lists the Longitudinal center of buoyancy not the transverse one so the position should only move along the Longitudinal axis which it apparently does.

 

so how will you know what the transverse cob location would be? Would'nt this
effect most of the calculations of heeled disp. and the like ?

 

Don't know...I'm still just working all this out...give me a bit of a chance. I'm just popping into the house between jobs. I'll have to wait until morning until I can do more exploring. Hopefully Martjin will pop in and give us some words of wisdom