Boats and foils comparison

Mozzy Sails

Super Anarchist
1,150
931
United Kingdom
You talking at hydraulic pressure versus surface pressure?

I think they will have sensors for flap rotation a several points along the foil. Then probably some fibre optics giving wing deflection. 

Nathan said in that interview about measuring when the load was zero, to raise the foil. I guess you could use pressure on either surface or the deflection of the span... but probably just a load cell within the arm would be the most direct way. 

 

The Advocate

Super Anarchist
You talking at hydraulic pressure versus surface pressure?

I think they will have sensors for flap rotation a several points along the foil. Then probably some fibre optics giving wing deflection. 

Nathan said in that interview about measuring when the load was zero, to raise the foil. I guess you could use pressure on either surface or the deflection of the span... but probably just a load cell within the arm would be the most direct way. 
Was unclear what Max was referring to initially.

Why would they measure deflection during racing? Testing possibly.

Which Nathan? If it is the parameter I think is being referred to, that would also be measured inside the boat.

 

Mozzy Sails

Super Anarchist
1,150
931
United Kingdom
Was unclear what Max was referring to initially.

Why would they measure deflection during racing? Testing possibly.

Which Nathan? If it is the parameter I think is being referred to, that would also be measured inside the boat.
I'm not sure what you would do with deflection along the wing during racing. But, I think it could be very useful for post sailing analysis. And if they're using fibre optics or something similar then it will be baked in to the foil. They're so light and low volume that I can't imagine you'd gain anything from having them be removable (even if it could be done non-destructively). 

Nathan Outteridge in his interview on PlanetSail. He was talking about making sure the foil was neutral (i.e no lifts or sucking down) before trying to raise it, to make a smooth lift. 

 
Rhino at USD 995 is way way beyond my budget, but I'll scout around for an alternative CAD app that can maybe do the same.  Thanks for outlining the procedure.  :)
The important thing is not Rhino itself, but the workflow.  I think just about any CAD package would have similar capabilities.  You might look into Fusion360 fro Autodesk.  It has a free version.

 

The Advocate

Super Anarchist
I'm not sure what you would do with deflection along the wing during racing. But, I think it could be very useful for post sailing analysis. And if they're using fibre optics or something similar then it will be baked in to the foil. They're so light and low volume that I can't imagine you'd gain anything from having them be removable (even if it could be done non-destructively). 

Nathan Outteridge in his interview on PlanetSail. He was talking about making sure the foil was neutral (i.e no lifts or sucking down) before trying to raise it, to make a smooth lift. 
Yes they could defiantly have some thin film tech or something like that I guess..

Sounds like NO is taking about tacking.

 

erdb

Anarchist
752
557
Hey @MaxHugen and @Basiliscus , check out ImageJ - a free image analysis software developed at the NIH. It has a line graph analysis tool that does exactly what you want. Long long time ago, I used it to digitalize paper recordings from physiology experiments. Just tested it in the current version and it works like a charm.

Converts a line drawing straight into a csv file or copy to excel. You will have to do the top and the bottom separately, because it's looking for a line graph, you can't have two Y values for the same X.

Download Fiji (Fiji is just ImageJ - literally  :D ), it has all the plugins already packaged in the download file:

https://imagej.net/Fiji/Downloads

Follow instructions under Analyze Line Graph: https://imagej.nih.gov/ij/docs/menus/analyze.html#graph

 

Kiwing

Super Anarchist
3,308
512
Bay of Islands
This thread is amazing!
While I don't contribute I still read avidly, not always following, until maybe a few days and bouncing around I catch up with the over all ideas.

Thank you all for your contributions!

 
Hey @MaxHugen and @Basiliscus , check out ImageJ - a free image analysis software developed at the NIH. ...
Thanks for the tip - I installed Fiji.  The thresholding tool is very powerful.  However, I think it may be expecting a cleaner image than is often the case.  This drawing is not AC or hydrofoil related, but it is typical of the kinds of things I'd like to convert to CAD.  I'll play around with it some more, and actually import something into CAD to see how that works.

SM55X_ SCALE_WING_CENTER_COCKPIT_DETAIL.jpg

 

MaxHugen

Super Anarchist
Hey @MaxHugen and @Basiliscus , check out ImageJ - a free image analysis software developed at the NIH. It has a line graph analysis tool that does exactly what you want. Long long time ago, I used it to digitalize paper recordings from physiology experiments. Just tested it in the current version and it works like a charm.

Converts a line drawing straight into a csv file or copy to excel. You will have to do the top and the bottom separately, because it's looking for a line graph, you can't have two Y values for the same X.

Download Fiji (Fiji is just ImageJ - literally  :D ), it has all the plugins already packaged in the download file:

https://imagej.net/Fiji/Downloads

Follow instructions under Analyze Line Graph: https://imagej.nih.gov/ij/docs/menus/analyze.html#graph
Thanks erdb, I'll check it out!

 

MaxHugen

Super Anarchist
Thanks for the tip - I installed Fiji.  The thresholding tool is very powerful.  However, I think it may be expecting a cleaner image than is often the case.  This drawing is not AC or hydrofoil related, but it is typical of the kinds of things I'd like to convert to CAD.  I'll play around with it some more, and actually import something into CAD to see how that works.

View attachment 435959
That's a pretty hefty looking profile, what is it for?

 

Xlot

Super Anarchist
8,690
1,129
Rome
SM.55.  I'm working on the design of a 1/12 scale model.
You might then want to check against the real thing - in the Italian Air Force’s excellent museum in Vigna di Valle, near Rome

I saw the only other surviving plane in the Bandeirantes Museum, São Paulo

 

MaxHugen

Super Anarchist
Thanks for the tip - I installed Fiji.  The thresholding tool is very powerful.  However, I think it may be expecting a cleaner image than is often the case.  This drawing is not AC or hydrofoil related, but it is typical of the kinds of things I'd like to convert to CAD.  I'll play around with it some more, and actually import something into CAD to see how that works.

View attachment 435959
I created a foil profile from this img in XFLR5, although I did not tidy it up using inverse design:

View attachment SM.55.dat

 
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