Hotel26

Here's an idle question. Can a wing produce more lift than 14.7 lbs / square inch? (Atmospheric pressure at sea level, STP).

Well, on reflection overnight, I'll yield on Bernoulli due to the following in the Wikipedia article itself on Bernoulli: An impediment to understanding is that Bernoulli's principle is said to be based on Newton's Second Law whereas action/reaction is the Third Law -- one might think they are independent and separate. In fluid dynamics with numerous molecules in action, a treatment with the Second Law might be much more tractable, but the Third Law still applies overall. And thus Bernoulli and Newton III can be interchangeably employed; the implication of which is that air is deflected as a reaction to the action of the wing. Hmm, one other thing, I think, was an impediment. The conservation of momentum may have been mentioned along the way. At first glance, thinking particularly of an airplane in level, un-accelerated flight, its momentum is constant. However, it is harnessing lift to counteract gravity. So for this force (under the circumstances which it is generated), some (less visible) reaction ought to be incurred. In 2003, I started a new job and a new colleague opined that science did not have a full explanation for modern flight and, in particular, Bernoulli wasn't particularly any explanation. I thought he was nuts, actually, because we know how to fly. The open question above is whether we do now understand the "why [it works]" well enough to have a complete consensus. But in any case, Bernoulli seems very restricted. And maybe that colleague was not nuts, either? (Thanks to those above who offered reasoned explanations.)

@wizzlebippi Thanks for the citation. Of note for me, is this: and also the distinction about camber vs angle of attack. I actually don't know which side this comes down on (and you can annotate that for me), but it does give me the opportunity to elucidate my "in some flight regimes" qualification. Passengers today spend the great majority of their time airborne at cruise altitude/speed in a regime optimized for very low angle of attack. At that speed, lots of lift can be produced but little (comparatively) is needed. (The article I cited in the other thread was criticized for being wrong in one point but it made the point quite well that a small pressure differential over a large wing area can easily generate the required lift for level flight at high speed.) At the same time, drag at high speed is a killer and the design effort needs to absolutely minimize it, which means eliminate turbulence and minimize any net deflection of the air. In this regime, if Bernoulli's effect actually exists at all, it may be that it is completely sufficient in and of itself to provide the required lift. (The reason this is particularly interesting to me can be given by example: I build a twin Panther machine that cannot break the sound barrier and @swjr-swis reworks the machine and it does Mach 2.5. He's done this enough times now that I fly the result and see that he has made small changes and the machine flies with some discernible inefficiencies in certain regimes, but by the time it has reached its top speed, the angle of attack is Zero and the drag penalty is as low as it can go.)

And this is what I think causes the endless debate about either Bernoulli or Newton as the cause for flight; that, in some flight regimes, there are a chain of "causes" and any can be cited even though none can be dispensed with.

A couple of observations: this debate has been going on (heatedly) in aviation/aeronautic circles for decades which ought to be a clear signal to the alert that this is not a black-or-white proposition. therefore being "correct" does not mean the other guy is entirely incorrect -- unless all you care about is "being correct". Newton's Third Law predates powered flight by quite some time. It is certainly true that momentum will be conserved, but perhaps that was not enough knowledge for Man to fly? Wilbur Wright uttered the metaphor, "a propeller is nothing but a twisted wing", which was a novel idea then to be communicated but it may be more helpful these days to think that both are just airfoils -- similar as airfoils but different in other ways. I personally guess that it is probable that you cannot deflect air efficiently (without undue turbulence) without understanding less obvious effects such as Bernoulli's and I wouldn't be at all surprised if a modern aeronautics 4-year program starts with 3 days to verify a student is sufficiently familiar with Newton's Laws and their implications and then spends the rest of the time on fluid dynamics and more. When the definition of a wing includes rubber-band powered balsa wings you can see that deflection of air is the purpose but when you look at the particular shape of a modern wing (an airfoil) and you ask "well, what makes this an airfoil and not a plank?", you get the first glimmer that what is going on on the way to producing the final result (including displacement of air) is quite a bit more subtle. (If you don't think this is important in modern aeronautics then consider that some of the first prototype parachutes were made of balsa wood -- and they did not work...) Being "correct" is fine but not so much fun when you have to accept that you are also being simplistic -- and dating yourself back in a pre-flight era. Finally, if you don't think there isn't something a bit more surprising going on than simply sticking your hand out of a car's open window, then think about a sailing dinghy tacking upwind. You might be certain that the sail is somehow deflecting air but you will have little hope of explaining how it does it unless you know[*] a lot more than Newton's Third. This is where "a propeller is nothing but a twisted wing" (in the 21st) equals a closed mind. * Thought experiment: predict what happens if you place spoiling devices on the windward side of the sail and then on the leeward and measure the respective differences in performance of the yacht??

Swallow Craftyard Description: A stock aircraft called Swallow. Built with 48 of the finest parts, its root part is Mark1Cockpit. Transports a command post to site for aerial deployment. Can be flown from the lander can. swjr-swis took an interest in the first version of this aircraft, which was a Break-Apart model, or maybe it was the test pilot's verdict, "flies like a cow", that caught his eye…? In any case, he has done a full work-over and we now present his rendition verbatim which is a thorough pleasure to fly and operate. Grazie, @swjr-swis ! Built in the SPH in KSP version 1.6.1.

Me too, actually. https://www.aopa.org/news-and-media/all-news/1998/november/flight-training-magazine/bernoulli-or-newton

They're having too much fun, posting a list of Top Suckers (like me) on their cafeteria noticeboard. That's OK, I moved the air intake forward to re-expose the top hatch. All my Pacemaker kerbals know how to F - Climb over the Mk2 cockpit nose to get to where they are going. That's another thing. Mk2 parts and ladders. Fageddaboudit...

I actually agree, in general terms, with both of you (i.e. and Geschosskopf), because I think you both have some reason and because the disagreement, if any, is only due to the subtlety of the aerodynamics. So you could say my intent is only to facilitate the communication and avoid simplistic renditions. "It's better to seek understanding than correctness"

An airfoil generates lift via Bernoulli's effect, creating a pressure differential between the upper and lower surfaces of the airfoil. An efficient wing deflects the airflow as little as possible to avoid drag, especially induced by turbulence. Propellers usually operate as airfoils, but aim to deflect the airflow (using Bernoulli's effect). The result is a vortex followed by eddying (turbulence). (Some of the same with wings, from the wingtips.) A car and a truck are the same, both using an internal combustion engine, but quite different in purpose. Similarly, wings and propellers are both airfoils but one used to produce 'lift' and the other to produce 'thrust'.

Truman is mightily pleased to announce an update to the Pacemaker... Update 2019-06-22: Pacemaker is now optionally powered by twin Junos and this package also includes a Pterodactyl delivery vehicle. At high speed, Truman drives with CAPS LOCK on, SAS off but to be engaged while airborne once the attitude is close to that predicted for ‘landing’. Pacemaker is considered ‘safe’ up to 60 m/s, after which it may begin to body-surf. All bets off in the mountains. 1/3 throttle is good for roughly 60 m/s. Do note that access to Pacemaker is via F- Climb over the nose... If you want to open it out to see what it will do, fly it out to Gilligan’s Island (6 21N 61 31W) – and have fun! (And don't forget to Quick Save before engaging Drive.) Work in progress to tune the suspension for safest performance at the top end...

Has anyone been able to do this? Or is it just not possible? The rear hatch of the Mk2 cabin is exposed but one does not get the Board prompt when a kerbal climbs the rungs into proximity with that hatch, no matter how the rungs are adjusted (by me). What is the secret? [KSP 1.6.1] UPDATE: well, it appears that the end hatches are not real hatches; just appear to be. Only the top hatch is really a hatch.

I guess everybody sooner or later goes this route: Thinking about the logistics of providing OX as well as LF to remote stations to keep rover fuel cells operational... This is an eXperimental version of Pacemaker[*] undergoing trials. Twin Junos... Can run without OX. I'm running a Pacemaker crew around a circumnavigation of Kerbin at the moment and know from experience that it can do 50 m/s safely as long as one stays out of the mountains... ...runs quick check on the KSC Green: 110+ m/s (before Green turned blue)... Running known routes (with known speed limits), I think this could be operated efficiently...? (While I'm here, why the heck is it that rungs under the hatch on the rear of an exposed Mk2 cabin do not under any circumstances allow a kerbal to board?) * credit to @Atkara for the base design of Pacemaker

Penguin Craftyard Description 1:engines 2:taxi 3:land/take-off A stock aircraft called Penguin. Built with 53 of the finest parts, its root part is Mark1Cockpit. Penguin is another in my Break-Apart series of transporter airplanes. Upon jettison, it deposits 1x Mk3 crew cabin + 1x Mk3 short fuel fuselage (2,500 kallons LF) + 1x pilot on the ground. The Penguin / Mk3 crew cabin combination is the Township cog in my global aviation network. It works in tandem with Swallow [the House cog] and the soon-to-be-published Eclipse [City]. Penguin takes off and lands on a sturdy but non-steerable LY-60 nose gear. An auxilliary LY-35 is provided for taxi operations. Depending upon the range to your final destination, the large 2,500 kallon fuel tank onboard is likely to remain fully charged until arrival. After jettison, it will come down on chutes to provide a stock of LF [but no OX to run rover fuel cells]. Built in the SPH in KSP version 1.6.1.

Penguin is another break-apart transporter that aerially deploys a Mk3 cabin: It has the beneficial property of arriving at the destination with as much as 8,000 kallons of fuel, which can be siphoned into the reservoir tanks of an existing base leaving just enough for Penguin to take to its natural habitat one last time before breaking apart to hatch the Mk3 cabin. Penguin can't break Mach 1 but that's about what you'd expect... And I've been doing a little kaizen on the RCS translators on Peregrine, my passenger SSTO: It's still pretty ugly, like a wart, but very effective. Two of these bracketing the CoM... The core is an octa strut. Two Vernors on in symmetry mode; then rotate the strut 90 degrees to put two more Vernors on. Top it off with one on top and then slide it down flush with the roof. Shift-click the octa to copy the whole assembly to go under the belly and all 3 axes are covered.

This is Swallow (which the test pilots say flies more like a cow) -- continuing High Kommand's complete obsession with aerial deployment -- depositing a 6-kerbal kommand post at Kamp David, 300 klicks north of KSC: Lanke neglected to transfer back to the Lander Can (SOP) before final cut-away and is somewhat lucky to be alive.

Ladybug Craftyard Isn't this nice? This is Ladybug and it has now been refurbished and repackaged to include a Zephyr lifter and a Sparrow tug. It's a complete set of 6 Ladybug munar explorers with everything you need to get it to the Mun or perhaps even further afield! If I'm not exaggerating(?), each Ladybug has 4.3 km/s dV. It can de-orbit/re-orbit easily on a single tank of gas. It's great for surface exploration on the Mun or for personal travel (economy class). Ladybug has VERT/HORZ control plus Pulse/Continuous mode switch. And to refuel -- new with this version -- a base docking ring for landing on top of a Goblin mining rig or to dock with a space station. Ladybug will completely revolutionize your exploration and knowledge of the Mun!

I'm using this mod in 1.6.1 and enjoying it, but am learning not to attempt to transfer kerbals from External Command Seats to anywhere else in a craft. The kerbal gets transferred but its body appears to remain as a ghost (fully opaque) and some part of the ship seems to get replicated around the general location of the "vacated" command seat. It's seems really easy to reproduce and in all cases I've had to ship a replacement ship from the KSC (by deploying the replacement on the runway and then editing the .sfs file to replace the bogus original (after getting all crew off) with the new one (not a lot of fun)). My question is whether this is a known problem? I can live with it now that I know not to do it...

Mule Craftyard Description 0:gimbal A stock tug called Mule. Built with 90 of the finest parts, its root part is mk3FuselageLF.50. Mule is a multi-role utility serving as: a tug in the orbital lanes, attached to a space station a munar crane for transporting equipment or fuel to/from the surface a mid-stage booster on interplanetary missions It is closely related to Atkara’s Drone Tug Mk1 and somewhat to my own HMS Beagle. Built in the VAB in KSP version 1.6.0.

I had thought about this and I don't think there's any way KSP can handle real rotor blades at that speed; so, no: I am perfectly happy the way it is! It's beautiful. And so much fun to fly on air-sea rescue... I'm glad (or hope) you're not mad at me for posting that (on the spur of the moment)! I like it just the way it is, particularly without the tail rotor!

I've started dabbling with BG. Naturally I'm starting with a Rev-Eng project: putting tilt servos onto Bloojay's magnificent V-Wasp Mk1 Servos seem pretty easy. Just ironing out some kinks... And..... it works! It's very easy and swift to land because the stubby little wings tilt up with the engines and you can wash off excess energy. You don't have to worry about it weather-vaning on the descent when the wings are fully feathered, so you can come down hard. And then BOOST the Panthers at the last moment to get those jackboots on the ground PRONTO... Hats off to Bloojay for his original, but this is now so much better with Breaking Ground. (The wings on his had to be flipped from one position to the other like flicking a hand-gun shut, had only the two positions, and -- there was a 1-in-6 chance the thing would explode or get jammed...) https://kerbalx.com/Hotel26/Wasp-H6

Dash 8K Craftyard Description 1:Wheesleys 2:reversers 3:flaps 4:ladder; 7.5km Vr:60 +2 inspired by Cavscout74 A stock aircraft called Dash 8K. Built with 40 of the finest parts, its root part is Mark1Cockpit. 545 m/s @ 7.5 km on 0.14 k/s Built in the SPH in KSP version 1.6.1.

It's raining here today and too cold to open the Lab SPH doors; so I've been rummaging around through some old stock and came across Cavscout74's Dash-8... My hat off to @Cavscout74 -- I am always impressed/inspired by his work. So I gave it a stretch and reworked the tail. I don't usually have the patience (or imagination) to work with RL, but I'm happy with this: the Dash 8K. It cruises 545 m/s @ 7.5km drawing 0.14 k/s. With a 4-cabin Mk1 meTro (1-engine) and an 8-cabin Mk1 Trident (3 engines), Dash 8K slots right into my Mk1 Wheesley fleet.

I took a Nerfjet mounted on an Escort escape accelerator for a ride out to my new Outpost observatory, which is positioned in kerbolar orbit trailing Kerbin, just outside its SOI but still within visual range. For no particular reason, I decided to dock the Nerfjet and Escort separately. Unloaded all the pax into the Outpost and undocked the Nerfjet, still brim full of fuel. It's something like 9d travel out to the SOI edge from Kerbin -- the Outpost is only another 5d traversal... If you put your monocle into your good eye, and peer deeply into the second shot (click to enlarge), you should be able to pick out Kerbin, its Mun on the left and also Minmus equidistant on the right. What a nice evening for space flight!

Outpost Craftyard Description: A stock observatory called Outpost. Built with 95 of the finest parts, its root part is crewCabin. Outpost is intended to be put into a Kerbolar orbit either just trailing Kerbin or just leading. It facilitates the easy "spread-sheeting" of trial maneuver nodes for plotting proposed interplanetary transfers. It’s also the ideal assignment for your indolent or inept space cadets! To position: raise Ap to 84 megameters (just inside Kerbin’s SOI) reaching Ap, raise Ap (on the opposite side of the orbit) slightly further to just exceed Kerbin’s SOI just after escape, zero velocity relative to target:Kerbin adjust orbital period to match 426d 0h 32m 24.6s fudge slightly as necessary The objective is to place Outpost at a Kerbin-stationary position just outside Kerbin’s SOI in order to make trips between Kerbin and the Outpost as rapid/efficient as possible. Built in the VAB in KSP version 1.6.1.