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3D Enlightenment
Canada
เข้าร่วมเมื่อ 21 เม.ย. 2021
Explanations using, Blender, 3D opensource software
Into the windsurfing footstraps - Physics explained
Explanation of the physics behind getting into the windsurfing footstraps and practical tips
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Change the way you think about windsurfing
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Using 3D software (Blender) this video will explain the physics behind windsurfing. This will cover the following: 1. Does the wind push or pull the sail? 2. What is the sail angle which provides the greatest lift force It goes over Bernoulli's theorem and Newton's Laws of motion and how they relate to sailing and flight.
Physics of Windsurfing
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Using 3D software (Blender) this video will explain the physics behind windsurfing. This will cover the following: 1. The force of the wind on the sail 2. Why the board doesn't get blown downwind 3. How you are able to sail faster than the wind 4. Does the shape of the sail provide lift 5. How to steer the board NOTE on Lift discussion: There is a point of confusion in the discussion of LIFT (5...
Thanks a lot!!!
You're welcome
👍🏻
Physics. It's the thing that makes sense of it all and life interesting. Thanks.
Bravo! Very useful and clear👏👏👏👏👏👏👍👍👍
The most serous and well done video on the topic !! Congrats for that model you made, deserves a separate video!
Thanks 😊
just saying, i think is coanda effect + newton 3law to generate lift, not bernoulli
Agree
Бред какой-то
Be specific (будьте конкретны)
As the board planes and picks up speed, apparent wind is much diminished and there is a significant change in the forces the sail experiences. This is why modern Windsurf sails are shaped so differently (and so differently compared to large, fundamentally non-planing sailboats). The mast is inclined towards the stern, closing the gap between the sail and the water surface (and the board). I'm quite convinced that lift has to be very significant there and the main difference in performance between older (70s to 80s) and newer sails. Check out race sails with cambers, too, and how they differ in performance compared to wave sails when it comes to top speed, the difference is drastic.
This is a great explanation. I've heard so many confused people suggest that it's all Bernoulli's law that matters. But the simplest way to understand lift is the best.
Use a spell checker. Spelling mistakes everywhere make your words hard to believe
Be specific please.
@@3denlightenment don’t ask me to do your job. Transcribe your captions and run them through a spell check
Thank you very much! Just the information I needed and didn't find before!😊
Glad you liked it!
love this!
Glad to hear it!
Slightly inaccurate but does the job.
Check out my second video for more detailed technical discussion th-cam.com/video/jHCXTiepjKY/w-d-xo.htmlsi=GW8uQ2IevY4HiaS8
windsurf community is lucky for these videos
6:10 if the wing wasn't shown upside down, the lift force would not be negative...
The simulation admittedly is a bit confusing, I would recommend watching the second video for additional clarity: th-cam.com/video/jHCXTiepjKY/w-d-xo.htmlsi=lb2o3YsrPcRZB_tj
You put a lot of effort into providing poor or misleading information. When did people start using cambered wings instead of flat plates? Well done.
Check out my second video for additional clarity on the science behind lift and forces on the sail. th-cam.com/video/jHCXTiepjKY/w-d-xo.htmlsi=ZtNHVwr3rOmgybMN
Good graphics, wrong info. No the wind does not behave like a billiard balls ona sail. Rather wing effect. And no, the apparent wind does not generally hit a windsurf at 90° angle, since a windsurf is fast, it comes from the front, even at angles of the board 120° off true wind.
Thanks for your comments. Please check out my second video which explains, through visual simulation and experimentation, the forces on the sail. th-cam.com/video/jHCXTiepjKY/w-d-xo.htmlsi=jcvjX1JSKw4ms-QX
Excellent. Why Spin outs happen, would have been a great addition to this video
This is an incredible video. So much work went into this. Great job 👏🏻 incredible illustrations. Love it
Glad you liked it!
Von Karman Vortex street would be a fascinating topic as it applies to Hove-To in sailing vessels.
Maybe. Something to think about. Thanks for the suggestion
thank you, looking forward for more
did your sailor's bikini shrink in the wash?
Must have...
i taught windsurfing for 4 years, if i were to do this kind of explanation to these newbies i would have lost all the students, of course we taught on dagger board style bords
Other instructors have found this video helpful. Admittedly some of it may be over the heads of a newbie, but nonetheless helpful. Regards.
Dear Mark top videos! Thank you for sharing your wisdom and passion with us! :D Would you kindly help us (me and my son) - as we are pondering on the science of how harness lines' length affects the forces on a windsurfer? Andrea Cucchi from Point-7 and some other Pro racers had noted that shorter lines result in more power while longer lines in more control. How come that shorter lines help the rider generate more power? When sailing 32 inch lines I noticed that am putting a lot of lateral pressure on the fin(s) but have a lot of control in waves and gusty winds, the sail is more upright or exposed to the wind. On the other side shorter lines might incline the sail more windward and 'hide' it from the wind as well as the angle of the force through the mast, feet and thus fin changes and/as the rider might be more on 'top' of the board. These are the types of questions I am bothered with at night :D So would be great to have a piece of your wisdom even be it just a comment if you'd care :) Much appreciated, Theodore and Andrey :)
@todomikolov9520 Glad you liked the videos. When it comes to harness length, I think it is easy to speak about power vs control, but I don’t believe harness line length has much to do with power, but would have some influence on control. Harness line length may have an influence on whether the sail is more “hidden” or exposed to the wind, but I would say that the greater influence on harness line length is the size of the individual, the height of the boom, and the type and position of the harness. The selection of length will depend largely on arm length allowing for a comfortable grip on the boom and enough control to allow rapid response in gusty conditions. Harness type, seat vs waist, will also influence the length as you will want to be able to get in and out of the harness quickly when needed. Of course, the boom height relative to the height of the harness hook is also an important factor. The power comes more from sheeting out or in the sail and not from the harness line length. The harness length may be able to be adjusted at most by 5 inches, and since it is a loop, this is only a maximum difference of 2.5 inches which is not very great. I hope that helps a bit.
@@3denlightenment Thank you so much! Surely it helps :)
It took me longer than I'd care to admit to notice he was green screened onto the beach. 😂😂
Thanks bro. I am about to start windsurfing this summer and this is exactly what I needed. Unlike other videos, this really helped in clarifying some basic mechanics. Cant wait to start
Great Video, great explanation 👍 Maybe you could turn the volume of the music down or the volume of you voice up a bit? 😉
Thanks. Good to know.
excellent ! Thanks
You're welcome
Sails, airfoils, barn doors etc do not make force in a moving airstream because the air strikes them. Very little air actually touches the sail. Sails make force because they create a pressure field in the moving air that deflects a huge amount of air most of which is pretty far from the sail. That pressure field does the Newton's 3rd law thing and pushes & pulls on the sail in the opposite direction.
True. Thanks.
Thank you so much.
You're welcome!
Thanks thanks thanks ❤❤❤❤
You're welcome 🙂
Davvero un video pessimo. Perlopiù arte grafica, ma pessima Fisica. Dovreste migliorare questo video. What a shameful English spoken video. Please, improve this video Physics informations and correct it.
I would appreciate specific areas you feel need corrected. It has been reviewed and substantiated by hundreds of thousands of people and supported by science.
@@3denlightenment Oh no, I don't review all its passages. Let's say that for windsurf - to go upwind: depitcing/visualizing wind particles impacts on sail and its component is almost useless in realizing how it works. Same so in scomposing those forces (in upwind direction)! In the video it is used the word "dynamic forces", the meaning? That it depends on velocity? That may be informative about module, not on DIRECTION of forces! So It doesn't help much in understanding HOW the windsurf can go upwind, too. The fact the windsurf can go upwind (45 degree o something like that... from wind's direction) lays in aerodynamics, so it is ABOUT THE PRESSURE between the sides of the sail, that is given by the FORM of the sail. It is right some parallelism with wings, that are present in the video. But I find that the video loses its direction after that. Then, how feet are "solid" or press ON the surf surface. No... that is almost about equilibrium of windsurfer against sail. The steer is about MOMENT of forces. Does the video use the word "moment"? Moment derives by feet pushing the surfboard (so involving some "direction", so no merely press down) or handling the sail, or both. I'm not an expert but these are my 2 cents :)
Thanks for the explanation. If I understand correctly you believe that the wind flowing over the surface of the sail profile will cause a low pressure on the sail i.e. Bernoulli's pressure and this low pressure will cause lift pulling the sail...however this is incorrect. If you watch my second video I conduct an experiment showing that basically it is newtons forces on the sail from direct pressures from the moving particles (dynamic forces) which provides the pressure on the sail allowing the board to move forward and upwind if needed. You speak about 'moment' which comes from momentum which is defined as mass x velocity. The foot pressures on the board would not be considered moments since they virtually have no velocity. You lean back against the sail with your body and legs at a certain angle and they, through gravitational and wind pressure, provide force on the board which translates to force on the fin allowing you to steer. Watch all three of my videos which should clarify somethings. All the best.
@@3denlightenment First: it is wrong to simulate a sail with a wing with double profile. Ok? And it is correct my issue about PRESSURE: in fact you see it when you blow OVER a sheet of soft paper (NO DIRECT NEWTONIAN IMPACT or "hits") that you hold by your hands from ONLY one side: the paper LIFTS because of velocity of the air over the paper is greater than velocity of the air under the paper. So different pressure on the faces of paper. Idem on a sail you have two sides, and different pressures on the two sides. You could define a "difference pressure" that you see it definitively "forges" the soft sail surface shape. You FEEL it on windsurf when going in upwind direction: the curvature of the sail (which is not rigid like a rigid WING, but it is more like the soft PAPER), bloats and pushing the sailing mast "ahead", so direct toward the semispace where the wind comes FROM. Ahead! About moment: NO! A moment is a "Newton* Meter" entity. You mistankely wrote about momentum (another and different entity involving velocity). Moment (in italian "momento") is about lever, couple or torque. It may involve rotations: its numerical value is a module of force multiplied by the distance between application point (of force) and the point where you calculate the so "referred" moment. So, on windsurf, you could push your feet downward in many way. But as on ship where you could walk on its bridge without change shilp-gait-stability, also like that on a surfboard: so the application point/s of feet may be changed WITHOUT involving new directions. But as rigid bodies, windsurf has a center of mass, so you can calculate MOMENT about that point. And also defilne "DIRECTION" by barycenter and board nose. Suppose a windsurf moves along an upwind direction, and it is stable in that. if you move the sail-mast leaning it nearer the nose (of windsurf), then it happens that there is more wind hitting the sail in a REGION between barycenter (center of gravity) and bow of windsurf, causing a change; image schematically this REGION force and its APPLICATION POINT, so a moment, a rotation from the previous stability, and in that case the windsurf obvously bears away. It works the other way about luffing. But again, (not starting by handling the sail, but BY your FEET), you could impress on the windsurfboard a moment (so a force with its application point and direction, and considering the distance of center of gravity of windsurf) , that involves a "rotation" around that center of gravity on the plane that is imposed by water surface, and so you have steering or change of direction! In the end: when you bear away from wind provenience, your body weight moving upward and nearer the sailing mast, all of this is involved: in your new equilibrium to react to sail force: but it is not merely pushing perpendicular over the board like walking on a bridge on a ship that changes direction. YOU MAY (or may not) impress a moment (referring to windsurf barycenter). IT IS in the way (pushing direction/s) of HOW you push your feet downward: so you have an entire vectorial semispace of (many) directions to choose from. Some of these previous explained things are ALMOST automatic by just the resisting to the sail-force while windsurfer body moving toward board's nose: so even if the MERELY moving of the windsurfer weight/body upward/downward along the windsurfboard (while contrasting the sail's force) seems to do the "trick", it is NOT the ultimate RECIPE, and it is NOT the ultimate reason of "steer", but really it almost MATCHES steering as a "side effect" by changing previous equilibrium forces, the EXACTLY-case given by the resulting of impressing a MOMENT (remember, the center of gravity of windsurf). Moment is the ultimate reason of steering.
@@3denlightenment Why have you deleted my definitive LAST explanation? Now it is lost. So let me just write that this video of yours is WRONG in many ways, as REAL Aerodynamics scientits should recognize after seeing it. 🙂
Fantastic! Thank you. I’m looking forward to seeing your next one
Your welcome!
Awesome video thanks so much! 🔥 One thing, the music is a little too loud in my opinion
Thanks! and thanks for the comment on the audio...I'll take note for the next one.
I also agree on this point as it distracts from the content imo. New to the channel. Excellent stuff & subscribed.
Love your content ! Always interesting to figure out the physics behind to understand windsurfing and hopefully increase performance. When talking about the "light wind" issue, wouldn't be more accurate to talk about "low speed" (board relative to the water) which would cause less pressure on the fin ? I think that the pressure that a rider is allowed to transfer to the fin through the back foot (without spin out or without drifting) increases with rider speed rather than wind speed.
True, the two are significantly correlated. I was just thinking that people generally experience low wind conditions when learning and don't necessarily consider speed as a factor but just look at the straps and give it a try. Thanks for the comment.
I can remember when starting windsurfing, i was looking at the fast guys that were sailing with a close sail. So I would close my sail with no speed and couldn't figure out why I was drifting. Apparent wind is unfair with beginners 😂
Great video thanks! I'm still struggling with the footstraps. It feels much more natural to me to get into the back strap first but then I fail to get the front foot in.
Thanks. Yes, that second foot, no matter which one, can be troublesome. You'll have to point the board downwind a little bit before you get that front foot in
5:15 In waves I put the back foot in first, to avoid standing so close with the feet. A wide stance makes it easier to keep the balance in the chop imo.
Good point. Thanks for bringing that up.
I really loved your 1st video that helped me a lot improve my windsurfing when I started a few years ago. (The second one too). Understanding the physics behind really helps a lot, especially for people learning by themselves… So many TH-cam videos with people giving advices which can be true but cannot be effectively implemented without understanding some prior concepts that most of these TH-camrs do not provide. So it’s really great to get information about the physics behind, which provides objective clues to understanding what one does wrong. Looking forward for your next video! I guess I speak for everyone saying we are all waiting for a video about the Graal of windsurfing, the Gybe /The laying down Gybe physics 😂 Your videos are really great so, thank you ! W
Thanks, and yes the Gybe would be a great one. I've been thinking about that too. Gotta feel like I've mastered it first LOL...but it's on the list!
wow
awesome
Great video. I wonder if you can provide a similar analysis for foiling ;-)
Thanks! I've never foiled before, but the physics wouldn't be that hard to figure out. I'll put it on the list.
@@3denlightenment that would be so good! Thank you
All these videos are very interesting. How does someone dig into this? Do you transfer knowledge from fundamental physics or are there resources on the physics of sailing or even windsurfing specifically?
I've not found anything as comprehensive on this so I worked it out based on my physics background
Very interessing video, thank you for your work sir!
You're welcome!
Great. Please consider similar videos on the physics of windsurf foiling. TIA
Thanks. Will do!
It's good to visualize these mechanics for an even better and faster understanding of windsurfing.
Glad you liked it...there are more coming
Great explanation. Well done for your research. Definately gives me a new appreciation. I'm just starting to windsurf. This is very helpful. Thank-you.
You're very welcome. Glad you liked it. There'll be more coming
Excellent ! Finally a video that explains this simply and clearly from first principles !
Thanks. Glad you liked it ☺️
5:00 this is NOT a sail, it's a WING. One side is longer then the other, it has a chamber. A Sail does NOT have a chamber. This whole video is completely false, sorry, as fance as it has been produced.
The model is a sail. You are right, it is not a wing. There is not a flat side on the underside of the model. It is hollow like a sail. It has a thin membrane over 3 struts simulating the thin shape of a SAIL. There are SO many videos where a sail is described as a wing. I am constantly showing the differences in the video. Your scientific discussion is appreciated.
3:30 is incorrect. The opposite has been shown, the air is flowing at the same speed and actually reaces the end on the downside first. Which makes sense because - where would the air take the energy to suddenly fly faster over one side and why would it do it? It doesn'T "know" it has to be faster to catch up.
Sorry. Watch this video here th-cam.com/video/UqBmdZ-BNig/w-d-xo.htmlsi=smeaY7Av6tCWbI2H
no, it does not have the profile of a wing. It has the profile of a sail. The air is flowing around it at the same speed, reaching the end of the äquidistant points at the same time, creating no pressure difference and thus no lift. It's all about the reaction force of bending the air into a curve. Basically the same as if the sail was completely straight, just more efficient because it produces less turbulences.
I agree, but so many explanations center around the curve of the sail and the wind flowing over it. The explanation of lift is often given as a function of air flowing over the leaward side ...which makes it like a wing. Newtons explanation is the air moving and striking the windward side. The windward side of a sail is curved as you state, but the wing has a straight flat bottom, but both provide surfaces for receiving the Newtonian force.