Nah man this video is lying to you it’s actually a group of guys under water pushing it around

@@chrisrobles824 fax

@@chrisrobles824 strenght:100

What was your rank Sir

Which rate? If ESWS qual’d, you would have certainly had to spend time down in aft steering learning the basics!

Holy shit no

@@user-lr6ce1mw4k yes

M now coming to Houston from.mexico

I second the flanking rudder video idea

i kinda feel the same way. shows again how anything can be appealing and interesting, if it's communicated properly. maybe teacher could take note.

Same here. One of these videos just kind of appeared in my Recommended out of nowhere and I watched and now I'm hooked.

@@borntochill bro I hate teachers, even an interesting thing becomes boring😵😵😵

Odlicni su mu uploadovi!

Heretic!

I'd guess ships aren't that common of an interest. I feel like most people wouldn't expect them to be interesting and would never really give them much thought.

It's quality stuff. Good, useful information. No glitz, no shouting idiot, no irrelevant shots. Excellent. Thank you.

236K is alot dude

Daniel Kaitel reading are so boring

Because not everyone is into ships? were you really not able to think of that?

I get so irritated whenever people use the 'speed' explanation as it is so inaccurate. I'm glad someone else knows about it! I wish this comment was higher up, or if Casual Navigation didn't make the mistake in the first place!

The Angle of Attack is an extremely important concept in aerodynamics. It's basically "how much angled the wing is in relation to the incoming airflow and so how big the chunk of redirected air is". Without this angle a wing will not work.

@@kramrle Dead link.

@@TimothyChapman Thx for the hint. Link is updated. docshare01.docshare.tips/files/3422/34223648.pdf

Both answer are good and are in fact needed. If you use only displaced air to get your lift, then how do you explain stall? Stall is the lost of the low pressure pocket of air above the wing, which is easier to explain with Bernoulli. The balance between the 2 depend on the shape of the wing, fighter goes too fast to really need Bernoulli, they would generate too much lift, so their wings are mostly symmetrical. If you look at a glider it's the opposite. At the end you can use both, if I was building a plane with a known wing, I won't need Bernoulli, but if I was building a wing, I would use it.

Thanks for further insight! Now that I think about it, what about the "portside" though...

@@jehoiakimelidoronila5450 since the rudder was on the right side, a ship could dock at a port on its left (or port) side. I am not that well versed in nautical terminology and history though, so if anyone knows their stuff better, please feel free to correct me

@@jehoiakimelidoronila5450 almost all ports required large ships to dock on their left side so the left side is called port sode

@@jehoiakimelidoronila5450 also, in German the starboard side is still called Steuerbord, and port side is Backbord, because most people the dominant hand is the right hand so the left is called Backhand, hence Backbord

@@mariebcfhs9491 the port side of a ship in English used to be called "larboard." it was changed in like the 16th century or so to reduce confusion for obvious reasons.

Thanks Matinalii

I race sailboats. On a friends boat, he had a NACA 0012 foil, but his photocopy of the leading edge came to a point, so he made it that way. It stalled so easily, it was difficult to get around the course. My own rudder is proper NACA 0012, with a circular leading edge, as it should be. I chose a non- elipically loaded planform, so that when the rudder starts to stall, it warns me, so I can correct it before I lose control of the boat. Also, appraoching stall at speed on my 19 ft boat can load up the hinge to around a 2000 lb load. I've had to replace bent 3/16" thick welded stainless steel hinges (gudgeons). You do know that sails work as foils, so that the generated low pressure allows us to go into the wind?

The Bernoulli effect not only effects our wings, rudder, and elevators in the air but also effects other things in a fluid environment. I was shocked to learn helicopters could stall to but when I thought about for a bit it made sense. This has also made how submarines glide underwater more interesting since those wings on the sides actually serve a purpose. Submarines can be controlled like aircraft underwater and can stall, but of course the ballast tanks cause it to behave like an airship.

In smaller boats that have an unbalanced rudder (so the center of friction is away from the rotation axis) a stall is not an issue, because the boat will still turn because of the friction, although it will lose more momentum.

Same as any control surface on an airplane can stall as well. They are usually designed to make that impossible as long as the aircraft remains within its design envelope, but either by external factors (icing for example) or flying outside the envelope (transonic speeds) can lead to stalled surfaces. Usually not an issue on the rudder, but it can happen to ailerons and the elevator, recovery from that issue can be very counterintuitive.

@@drewthompson7457 A concept I have to teach newbies on my boat. Don't stall the keel or rudder. Funny about your friend's photocopy. I should make a template and check the profile of my rudder ad keel. Rudder looks like NACA 0012 but might not be. Keel is not but is a compromise like most things.

Right? I didn't quite expect that.

It would have been more helpful to point out which specific concepts have been misrepresented here, as opposed to just giving an unhelpful and quite frankly lazy critique.

Robin Marquardt what makes you think that there is no speed differential across an airfoil? Every advanced textbook on fluid mechanics I have studied in both undergraduate and graduate school has dealt extensively with airfoils and there is speed differential. Granted the mechanics of an airfoil are extremely complicated (entire PhD dissertations have been written on the subject) so there is no way it can be described in a few sentences, but the basics can be understood by reading a good textbook in introductory physics if you want more information.

@@GregKittle aor does not flow faster or slower across an airfoil because there is a longer way. If corrected for Bernoulli's principle, there is no difference. I actually did experiments and in addition real life applications suggest otherwise. I spend 120.000$+ on this stuff btw. The fact is that what is taught is not what's actually true. Those are theories. As of now there are 3 accepted theories on how lift is actually created.

@@GregKittle air above an airfoil has no intention to end up next to the molecule it parted ways with before hotting the leading edge.

@Agamemnon1002 yes

@Agamemnon1002 the air above the wing is not faster because it has a longer way to the trailing edge than the bottom. It is a common misconception. For one air wouldn't have to or want to end up at the same time at the end of the wing(top and bottom) and in experiments it's seen that it doesn't.

I would agree except YT hid the counter for some BS reason.

So you're saying you're better than everyone else watching this video?

KurryCane he was implying that airfoils are not interesting to most people but even I love this

Thanks Shayan. Glad you liked it!

Yes please!

Yeah, it's a bit off

what part of the video are you talking about? This part 2:45?

He's correct - he wrote slower water flow is higher pressure, which is true from Bernoulli's equation?

Ya, lp=high speed, hp=low speed fr airfoil to create lift

FOOL ! Airfoils operate in air , think about it , there is a clue in the name . Backwards is a single word . The man was correct and unlike you did not make a fool out of himself .

Thanks Talking Human. Glad you found it interesting.

The Casual Navigator I thank you that it is interesting.

so the rudder is so big, it has its own rudder?

I heard that and I thought I was losing my mind.

Thanks Anup. Those are good ideas for future topics

f12mnb A rudder at the forward end is not a new concept. There are a handful of ships with them already, but these generally only have a bow rudder when the ship is designed to be run astern for a prolonged period of time such as some icebreakers and ferries. A rudder at the bow for a ship moving ahead would not be able to steer. This is due to the vessels pivot point. A pivot point is quite difficult to explain here because of the complicated hydrodynamics involved. But, in simple terms a pivot point is a point about which a vessel turns. When a vessel is moving ahead, the pivot point is near the bow....so when a rudder angle is applied the vessel turns easily because the force of the thrust acting on the rudder has a long lever to push on and will be very effective. Imagine trying to undo a very tight bolt with a spanner.....if you use a short spanner you only have a short lever and will use a lot of effort to undo the bolt. If you use a longer spanner, you don’t need to use as much power as the lever is longer. The bolt in this case is the pivot point and the other end of the spanner is the rudder. The shorter the distance between the rudder and the pivot point means the ship is harder to turn, the further away from each other they are, the easier it is to turn. Chris - Marine Pilot

@@marinepilotchris3048 Thanks - like the analogy.

@@marinepilotchris3048 Thanks for the reply. I've been thinking over your answer and analogy and quite like the spanner/wrench analogy. Which makes me wonder, if instead of just a rear (standard) rudder, a vessel has two sets - a main rear one and an auxillary one in the front. I'm thinking of the land analogy of very long vehicles that have a front and rear steerable wheels (older long ladder fire trucks had this arrangement). Since you are trying to pivot around what sounds like the center of mass of the ship, this is like have a large two armed tool - like some drill taps or tire irons where there are two arms from a center pivot point. It would add to the complexity of the ship but might make it easier to turn or dock some vessels.

f12mnb in order to achieve the manoeuvrability of vessels about the centre of mass bow thrusters are used. A bow thruster takes many forms and designs, but by far the most common is the tunnel thruster where a prop is placed in a tunnel athwartships through the bow of a ship. When the prop turns it sucks water from one side of the tunnel and ejects it from the other side. This will provide a turning force much greater than any bow rudder could produce. Don’t forget that a rudder needs water flow over it to have any effect. This would mean that if the ship was stationary and wanting to swing about the centre of mass, then you’d also need a bow propeller to provide that flow. The expense of installing a bow rudder would not be cost effective when a simple bow thruster does the job much more effectively and doesn’t require the ship to be moving ahead/astern to give its full turning power.

@@marinepilotchris3048 Thanks - that makes sense. Forgot about thrusters. Much easier to control and no need to have flowing water over the surfaces.

The reason extreme designs fail is due to flow detachment, not because the principle is flawed

To be fair it is a rather common and easy to visualize explanation and I think for the purpose of this video it's more than sufficient.

Most of the lift is generated through Newtonian vector physics but some lift is generated by streamlined fluid flow around the airfoil allowing for less drag for same amount of lift.

Keep in mind who your target audience is. Sometimes a more accurate model isn't better at explaining stuff than a more intuitive one.

David Szeto conservation principles are more intuitive as well. The whole idea of “molecules on one side have to flow faster on the other side to keep up” is bologna!!! How do the molecules on one side of the foil know they have to keep up with the molecules on the other side??? They don’t. I understand your point, and I’m not trying to be over critical of this video, it’s interesting and well made. All I am saying is for anyone interested in the physics of aerofoils learn the momentum approach. The pressure/velocity approach is a bunch of hand waving mumbo jumbo and it pains me that they still teach this in high school physics. Thanks for your response!!

I have not covered acts and publications yet, as I don't find them as interesting as navigation itself. That's why navigation is the main focus of this channel.

I think it is probably negligible compared to the ship itself. I guess drag is only really a consideration when the rudder is straight anyway. As soon as it turns, the drag helps with the turn. Would be interesting to see the different fuel consumption with different rudders though

@@CasualNavigation Probably also has less of an effect for the ship as the rudder is tiny in comparison to the hull of the ship and being centre mounted doesn't really add to the hulls cross section in the water and of course it's contained within the slipsteam of the ship. Aircraft on the other hand have a minimum of two giant aerofoils sticking off the side of the aircraft, most of course also have two smaller upside down aerofoils (horizontal stabiliser) and the vertical stabiliser at the rear too none of these really get any slipstream benefit from the main fuselage so that probably adds to the much greater significance on the total drag. Plus the aerofoil design of the wings means they constantly produce induced drag as a side effect of developing lift too so anything that can be done to optimise this to a minimum especially for a craft that operates at such high speeds has massive effects on efficiency, thus such as the use of winglets to reduce the amount of vortex shedding which significantly increases induced drag.

(rudder x fuselage)

I read that the generic term was damned by President Hoover.