Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Posted (8 years 1 month 1 day 20 hours ago) and read 6420 times:
Vorticies are something I view as a problem and I wanted to know if I could prove the boom issue via ground effect for slower planes. I didn't want to start another ground effect thread, just that was my original intent for the other.
Noting that during sonic compression lift, the shockwave cuts off the induced flow from vortexing over the top of sonic wings, I thought that was a form of "highspeed ground effect" by itself and that the reflected energy that pronounces the lift on planes close to the ground resulted in more intense sonic booms. The wave cushons the plane but the reaction is pushing that air down (like downwash) directly into the ground, all the way down, though it looses intensity on the way.
That's all, a simple thought to a simple theory: That the waverider/compression concepts pronounce boom intensity. I figured that if that energy was allowed to spill over the top, the boom's intensity would not be as strong. A majority of Concorde's wing lies within this compresion, only it's 70-degree inboard leading edge can allow induced flow to escape.
That sonic induced flow has to go somewhere, for subsonics it is called downwash for a reason, it goes mainly down and back. But in a shock wave it has no choice, can't go sideways. It is to me likely dynamically based, that it is increases with speed (I figure again it is similar to slower planes or even ground effect machines like Ekranoplanes).
I always believed that speed, size, shape and stationary (altitude) can all vary the boom's intensity.
A sonic downwwash may contribute greatly to the sonic boom PROVIDEDthe wing of the aircraft was the majority airplane top view profile planform surface. For example Concorde's wing is 3700 sq.ft. and the total is 5400 sq.ft, that's 78% boom contribution.
Which poses a question, would a smaller wing create a smaller boom? No, it would be larger. How do I figure? Wing-loading is related to boom pressure, IMO it is obvious, by a greater dynamic downwash (well, kinda). Pick any sonic plane, doesn't really matter. If you vary the wing area, you vary the boom carpet; yes but, if the weight remains the same, it ain't good. A larger displacement pressure is exerted as the planes pushes that air aside, the wing just forces it up or down.
CONCLUSION: In addition to non-compression lift wing, give them a high dihedral.
ADVANTAGE: That would force the up-and-down shock wave reflection somewhat sideways where it doesn't matter. This would further spread out the boom intensity carpet. Let's take Concorde, tilt her wings up by 20-degrees and her 80-mile wide carpet become closer to 500 miles. I estimate the boom intesity will reduce by 4 times to a half-pound per square foot, at least.
DISADVANTAGE: Yanking up the wings means the lift vectors are not just lifting, they are also bending the wing inwards -- this is a structure stress issue. I still see it as a stability or control issue. Secondly, an non-compression lift or non-waveriding wing will force a plane like Concorde to fly slower to allow for vortex lift to occur. This results in serious engine inefficiency. By looking at it's outboard 50-degree wing sweep, M1.65 would be the limit, I wonder if she'll stall at that speed at FL600...
In other words, the design of that type of plane under these circumstances would have been flawed. And since a very large majority of transport designs are based around that common shape, it is why I believe not all designs have been tried. Was there any reason to? It would be nice to make the plane lighter, but considering the square-cube theory, a larger plane will have had a higher loading and thus higher boom. I read in an aviationweek magazine one time that the estimated boom pressure for the late-HSCT would have been a whopping 3 lbs/sq.ft!
It make perfect sense to either aim for a regional sonicjet less that 120 seats or a business sonicjet. Those type of planes in the commercial field would beneft greatly from neo-seni-radical designs.
This was the basic premise of AntiShock V8.x, to only consider aircraft profile and reactionary pressures.
The meaning of life is curiosity; we were put on this planet to explore opportunities.
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 1, posted (8 years 1 month 1 day 13 hours ago) and read 6219 times:
Here is a basic model to describe what I'm talking about. I hope it is not to difficult to understand, it's in 3D. Coordinate below on the right side, there is no scale, its just a model shape.
length is about equal to width,
AR=1.0,
it is a flying wing technically with dihedral wing canted @26-degrees upwards.
Model satifies area rule, has no tail or engine, for clairity of wing-body structure. Twin jets would be placed in the back on top (noise reduction) and twin fins at wing tips (control & stability)
Target velocity must be less than leading edge Mach equivalent of wing for this quick sketch to allow spilling of vortex, in this case, less than M2.0.
For perception, I guess you can assume a 1:120 scale per XYZ coordinate segment, so the whole thing is just shy of a 100ft x 100ft plane. Even if it weighed as much as similar planes to it's dimensions, the loading would be dramatically smaller and hence a less intense boom results.
For this project I have devoted all attention to the shape of the aircraft and none to the engine.
Please ask questions or comment, I'm taking a risk by showing you guys what I mean, your input is important to me.
BTW, that shape originated from AntiShock V4.0, it was inspired by a potato chip at my school cafeteria in November 2002.
[Edited 2004-04-27 03:17:01]
The meaning of life is curiosity; we were put on this planet to explore opportunities.
Wilcharl From United States of America, joined Jun 2000, 1158 posts, RR: 3 Reply 4, posted (8 years 1 month 1 day 9 hours ago) and read 6146 times:
Sure glad i went to daytona instead of prescott.. but then again i might have come up with something brilliant having nothing to do but figure these ideas up sitting out in the desert.
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 6, posted (8 years 1 month 20 hours ago) and read 6016 times:
I donno about that Backfire, I have a slow modem and I'd have to go to school to check it out, I have no class today.
Edit: I did read the abstract, they were discussing methods of boom testing from the 1980's and such. yeah, uh, I don't go to the nasa's website anymore, i'm kinda angry with them since all they normally do is space shit. 'cept x-43, but then their intent is to replace the space shuttle, so there you go. they should change their name to NSA, national space agency.
I'll be ignorant for now...For what I remember of the ex-HCST that NASA and Boeing were trying to create, all bets were on laminar flow, from what I remember, to reduce drag. Maybe they had something up their sleves, but the fact they did not communicate via any [media] publication -- which is the only real way to advertise this product to market -- is that they might not have had to give much of a darn for the sonic boom. Like their always, it was designed for supersonic overwater and subsonic overland, that is just how it was. That's still how people think.
Since it's cancellation in 1999, Boeing secret studied what was revealed to be the Sonic Cruiser a year later; by cancelling that it did not help the idea of sonics in general very much. NASA then switched gears to focus on the X-43's R&D project that was proposed/started back in 1996; that first crsh did not help the aerospace community very much. Also in 2000 or 2001, the Pentagon issues a competition between defense contractors Lockheed-Martin and Northrop-Grumman called QSP (Quiet Supersonic Planform) in which some of the result were publicized in Fall 2002. Of course the news was over shadowed by the JFS competition winner, X-35. Which is why some kingpins on this site have their mentalities like they observed Concorde's run and made a decision.
I've looked at Nothrop's concept, it doesn't look like thier pelican nosed F-5, whci is where their data of "7 times less than Concorde" came from, an increase in size will lower that number. But then it was a defense competition, it would not have standards like the commercial industry. Furthermore, they wouldn't share those ideas, i.e. they are not helping the idea of bringing one into commercial service.
I've seen a lot of concepts and proposals, though a sonic bizjet might be 'revolutionary', its shapes are not. Same shape = same sonic boom, just less intense by size.
[Edited 2004-04-27 20:02:22]
The meaning of life is curiosity; we were put on this planet to explore opportunities.
QantasA332 From Australia, joined Dec 2003, 1500 posts, RR: 41 Reply 7, posted (8 years 1 month 14 hours ago) and read 5952 times:
In addition to non-compression lift wing, give them a high dihedral.
One fairly big problem with that has to do with lateral stability. Most transonic/supersonic/hypersonic aircraft (obviously including the one you're proposing, Lehpron) have a quite large amount of wing sweep, for obvious reasons. One side-effect of sweep is that it increases effective dihedral by virtue of the altered alignment of the wing's chord, thus increasing side-slip stability. The combination of large sweep and dihedral means the aircraft would more than likely be overly stable, a condition almost as (if not as) undesirable as instability...
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 8, posted (8 years 1 month 4 hours ago) and read 5880 times:
Well, yeah, i figured it would have stability issues, just kinda figured that is what fly-by-wire is for. If it may seem overly stable, imagine the stall characteristics...
AUAE, that edge does appear to me at around the 50-degree region, that means it has a slightly smaller aspect ratio and it Mach max would drop to 1.7 or 1.6.
I saw those concepts on that NASA link: absolutely hideous. Shape says it all, wasn't too interested in their data. For one, I thought the 80 x 80 meter box limit for airports applied to all planes, why are those NASA boys insisting on a 330-foot plane?! The wing planforms (top wise) passes with me, but the overall setup fails, I would never place engines underneath. Not only are they loud(er) under there (sound reflects off wing too), but shockwaves come off of them naturally as well.
I'd push for designs having the entire underside of the planes are CLEAN so that no other waves are created in addition. I'm not talking about expansion waves. Anything on the plane will give off their own "bow and tail waves", fuselage, wings, fins, engines, etc; with each own's intensity varying on area. Unless the engine was buried in the fuselage or wing, forget placing them there.
As for this proposal, i might be able to come up with a 3-view concept for those of you who are interested, let me know what you'd like to see first. I was thinkin of posting that follow-up in the Civ forum and let this thread be the technical part... I sincerely thank those of you who have responded. It's good to know my risks are being appreciated.
For disbelievers, if you're gonna make a fair comparison, make sure the wing loadings are the same. Please ask a lot of questions too, by the number of views against number of responses, I feel a bunch of folks are just confused.
[Edited 2004-04-28 12:09:00]
The meaning of life is curiosity; we were put on this planet to explore opportunities.
AUAE From United States of America, joined Apr 2004, 296 posts, RR: 5 Reply 9, posted (8 years 1 month 1 hour ago) and read 5849 times:
Not confused, just a bit busy right now. Unfortunately I haven't done much work in Supersonics. I skipped that class in undergrad and went for one on hypersonics. Doesn't mean I know much there either! But at least I have a good book on that.
I was asking about the degree of sweep so I could start picturing everything. For instance, thinking about a simple cone or wedge of the same degree, ect.
Since I can see you are a visual reference type of person, here is one thing I am wondering about. The sweep is pretty steep, so the oblique shock angle should end up pretty steep. Your dihedral is pretty steep also, could you possibly end up with the tips getting close to the shock on the upper side?
Second thought, your design to me looks more like a lifting body. Is the intended design route that you are taking, or do you mean for it to look more purely like a flying wing?
Shawn
Air transport is just a glorified bus operation. -Michael O'Leary, Ryanair's chief executive
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 10, posted (8 years 4 weeks 1 day 13 hours ago) and read 5736 times:
Don't worry dude, I'm not harping on you, just that with so many views, so few responses and that I revealed something I thought I never would, I'm kind of anxious.
>> " Your dihedral is pretty steep also, could you possibly end up with the tips getting close to the shock on the upper side? " <<
Definitely not. Imagine that the wings could rotate up and down from the root of the fuselage like the wingtips of an XB-70. As they rotate, their position with respect to the shockwave stays the same. In this case, the wings are fixed upwards. The wing-body leading edge is in reference to the shockwave angle nearest to. Remember, the idea is NOT to wave ride. Lemme tell ya, it's damn hard to draw in 3D in MS paintbrush, I'm glad the pic looks okay.
>> "For instance, thinking about a simple cone or wedge of the same degree, etc. " <<
Take a 3x5 card and cut out a shape similar to that, basically 53-degrees back in front and about 13-degrees forward in the back (like a funky diamond), it should total to a length = width. Then bend it centerline.
>> "Second thought, your design to me looks more like a lifting body. Is the intended design route that you are taking, or do you mean for it to look more purely like a flying wing? " <<
To be perfectly honest, I do not know where a flying-wing ends and a lifting body begins. Traditionally, as long as it was of low wing sweep and standard airfoil cross section, it was a flying wing. Wing sweep wise, that seems to me like a ridiculous discrimination. I do not make that differentiation, except with lifting bodies, don't know why though. Their cross sections do not always have to be airfoil-ish. The ones I'm accustomed to are the wedge shapes like X-30, Aurora, Hypersoar and X-43 and I've used them in my older hypersonic concepts. I discovered that these wedge shapes displace their own downwashes, definitely not boom friendly. I've changed them and there is no way in hell I'm showing them off. Nevertheless, they are beautiful and efficient, the speed freak version off the flying wing. Damn costly to build cuz it's an integrated set. You cannot use even traditional X-15 or X-23/24 era knowledge on these. Well, materials from X-15 and stability & control from X-24 yes, but not elsewhere.
You are aiming for the hypersonic field. Good for you; would that be low hypersonic (M5-12), mach teens (M13-19), or high hypersonic (M19+)? That is just how I've categorized it, over the years I see too many folks making assumptions here and there about hypersonics that I have had to straighten them out. Many I know assume the space shuttle for any hypersonic, you cannot lump all that speed into one idea! I actually want to pursue hypersonics, but I'm starting to see less of that available in graduate programs for any affordable college. In addition, there are so many naysayers in the supersonic arena that I felt it was necessary to research this.
Trivia: My username is named after a hypersonic concept project that I've officially started in September of 2000, though initial sketch was in April.
The meaning of life is curiosity; we were put on this planet to explore opportunities.
AUAE From United States of America, joined Apr 2004, 296 posts, RR: 5 Reply 12, posted (8 years 4 weeks 1 day 11 hours ago) and read 5712 times:
Well I wouldn't say I am aiming for the hypersonic field since I work for an airline now. I just had more interest in taking the class in undergrad than I did in supersonics. Turned out to be a good thing, the equations were much easier to understand. My favorite: L/D = cot(a) Now that is a beatiful equation, and a perfect for a flat plate flying really really fast. The book we used was "Hypersonic and High Temperature Gas Dynamics" by John Anderson. Add it to your collection.
I think I see a flaw in reasoning before. The shock angle is going to be much greater than I was thinking. (from above, I am assuming your target velocity to be between 1.6 and 1.8 Mach) Assuming weak shock, at M 1.6 the smallest shock angle is about 39 degrees for no turning flow, and for M1.8 the smallest shock angle is about 34 degrees for no turning flow. I was thinking the shock was going to "lay down" a lot more, but you need a lot more speed for that to happen.
Anyway, to continue on, using your geometry, b=100 feet, and length = 100 feet, and dihedral of 26 degrees.....
I get a height of app. 24 feet to the wing tip. The angle from the nose to the wing tip (strictly viewing from the side, not talking a 3d measurement here)would be about 13.5 degrees. (Man, hope I did that math right!). Assuming this 13 degrees is the turning (flow, or deflection) angle, and assuming a wedge shape, the shock would attach and be at about a 58 degree angle for M1.6. Similarly, for M1.8 it would be around 48 degrees. No where near as close to the aircraft as I was thinking. But then again, I never really think about shock waves. If we assumed a conical shape, the shock angle looks like it would be less, around 35 to 38 degrees or so. Still though, not close to the body like I was thinking.
So you can see what all I was thinking about, just basic ideas about the shape. What if it was a wedge. What if it was a cone. Does the shock attach. Leads into the other question I had. Lifting body or more flying wing...guess that is ambiguous, but I was thinking lifting body, big and fat profile; flying wing slinder profile. If you were thinking along the lines of lifting body, you could start with crude approximations using basic shapes: cone, wedge, half cone, half wedge, ect. Given your comments on the past x-planes I can see this not your idea. Then it looks as though most the work revolves around how the wing reacts in supersonic flow. Not as easy for me to visualize.
Anyway, have to leave on those half finished thoughts. Got to get my butt to bed.
shawn
Air transport is just a glorified bus operation. -Michael O'Leary, Ryanair's chief executive
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 13, posted (8 years 3 weeks 6 days 14 hours ago) and read 5569 times:
>> "My question would be relative to actually getting enough lift out of that wing shape. A lot of the lift vector is being lost." <<
That was what I meant by wings bending inwards due to lift. The result is to either travel faster, increase lift area, decrease density or increase coeff of lift to compensate. Like I said its a structure issue.
>> "I think I see a flaw in reasoning before." <<
Who's reasoning, your's or mine?
When I sketched that lil'pix up I did not figure scaled values, those numbers I gave were on the spot and not calculated. Your reasoning was not in vain, I learned something from your inforants. My laptop died yesterday and little has been recovered, so I lost a lot of info that I could have posted among other things.
Like I said I'll try to get a detailed one (plane and technicals that you were trying to figure out) up for everyone to criticize by late next week. I think I will stick that in the civ forum as it would be their problem too.
Hey, some of those folks are part of my target market, go figure.
[Edited 2004-05-01 02:12:35]
The meaning of life is curiosity; we were put on this planet to explore opportunities.
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 14, posted (8 years 3 days 13 hours ago) and read 5062 times:
Slight update or an after thought:
I see conflicts in the one of my theories above. Over-pressure due to sonic downwash may not be the only variable. From a drag perspective, there are three types of drag acting on a sonic plane: parasite, lift induced and wave drag. The sonic downwash may be the version of lift-induced boom. From the way, it was worded and from the way, I now perceived it, sonic compression may yield from at least two different sources. One is the mass of the plane over the total surface planform. All factors held even, the only thing that changes behind the shockwave where the plane exists is dynamic air pressure, varied by static density of air multiplied by velocity squared.
Quite technically, this pressure must drop as the plane passes from that instantaneous point where it was measured. This pressure must be reflected (or absorbed then reflected) off the plane. This pressure over area results in a force, which is not the drag force; it is the force of the boom, due to bow, expansion and tail shockwaves.
Think of a boat on the water and we are floating in a stationary spot. Up front, everything is calm, and then the boat arrives. Whoa, suddenly there is a bow wave, a bunch of uneven expansion waves coming off the boat's hull and lastly the trailing wave. As it passes, were in the wake and eventually the water it calm again.
Well let us examine this. 1) It has it is displacement in the water, being its weight against the area it has over the water, its footprint if you will. 2) The dynamic pressure is, like air, density of water multiplied by its velocity squared being multiplied by whatever surface area exists in the medium, in this case water, which results in a force flowing away from the boat. 3) The shape of the bow. Considering that just behind the wave has the highest pressure gradient, think of Newtonian wedges; not only is there a reaction to the boat (it terms of drag) but there is a reaction of water being thrown off to the side and underneath. If you were floating next to it and it passed, you would be tossed, slightly. In terms of an airplane wing, the underneath would be downwash. The airplane's fuselage however should be displacing air regardless of the wing, in this case, outward in all directions.
Shockwaves on a plane do not just go up and down on an airplane, they go outwards in all directions (like water ripples, but in spheres), except that because we live under a flight path, we care for what happens under a plane.
The meaning of life is curiosity; we were put on this planet to explore opportunities.
Dl021 From United States of America, joined May 2004, 11372 posts, RR: 88 Reply 16, posted (7 years 12 months 19 hours ago) and read 4749 times:
Lehpron....I don't understand 70% (in other words the math and the acronyms are pretty much Greek) of what you said, but I do know that invention and advancement come from unflagging effort, optimism, and occasionally desperation. Please continue with your work. At some point enough data will be gathered in this field and somebody like you will figure out how to get us flying faster, economically and safely. THanks for the work and vision. Good Luck!
IMissPiedmont From United States of America, joined May 2001, 6050 posts, RR: 50 Reply 17, posted (7 years 12 months 11 hours ago) and read 4697 times:
You, Lehpron, can solve a probelm that's been vexing engineers for 60 years? Yet you cannot explain why tires get hot.
Would you then be some sort of Einstein? He did come up with amazing theories but was hard pressed to explain simple things like internal combustion.
I think a test for people to live in the southwest US should be no A/C in the car for a summer.
Starlionblue From Greenland, joined Feb 2004, 15104 posts, RR: 69 Reply 18, posted (7 years 11 months 6 days 13 hours ago) and read 4484 times:
Wanted to bump this topic since the current issue od "Popular Mechanics" (I'm pretty sure it was PM, but I didn't have time to stop and look) features "Quiet Supersonic Aircraft" on the cover. The wings of the pictured plane have a very pronounced dihedral.
Just thought that this might interest some of you
Tact Is For People Who Aren't Witty Enough To Be Sarcastic
MNeo From Bulgaria, joined Mar 2004, 776 posts, RR: 1 Reply 19, posted (7 years 11 months 5 days 23 hours ago) and read 4425 times:
call me stupid (because i only have very basic knolege of physics yet) but if thne wing is in a diomond shape (if thats even possible) then wouldnt the sound boom be smaller because the last part thats breaking the barries has a small SA.
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 20, posted (7 years 10 months 4 weeks 11 hours ago) and read 4269 times:
Starlionblue, I noticed the magazine and I am kind of in awe you remembered this thread, thanx dude. Sooner or later I will update my website with info on my concept, or one of them. I already began to work on another; a bigger, faster sonic.
Mneo, you're not stupid, you're ignorant for not knowing yet going ahead. But that is a way to learn so I'll let it pass.
Second, the above pictured wing is not a diamond, it is more a delta closer to Concorde without the S-curve. Why did you think a diamond shape would not be possible, would it be because you have not seen it [as often]? The YF-23 by Northrop that competed with Lockheed's YF-22 in the ATF program had a diamond wing with both leading and trailling egdes @ 41-degrees sweep. But then it was not designed specifically for dealing with the boom so no conclusion should be made on it.
>> then wouldnt the sound boom be smaller because the last part thats breaking the barries has a small SA." <<
Before I get really complex answering that, I'll say that it doesn't matter what each individual SA is, it is the total top-view footprint that matters, including the fuselage and engines. One boom characteristic is the effect of load, which is the instantaneous mass over total area. Which means the boom is actually louder after departure than across the whole flight. But it is just a piece, overall shape changes it a whole lot more -- the plane itself is after all the source of the sonic waves. It should stand to reason that its shape will change the boom. Just what and how much has yet to be determined.
That said, there are not many designs/tests that investigate the effects of trailing edge wing sweep, say nothing of the fact that there have not been many tests have been done with regards to sonic boom manipulation and here I am with these theories. That is all they are until tested or proven one way or the other. My bias is that I believe in them.
The meaning of life is curiosity; we were put on this planet to explore opportunities.
DAL7e7 From United States of America, joined Jun 2004, 357 posts, RR: 4 Reply 21, posted (7 years 10 months 4 weeks 9 hours ago) and read 4263 times:
Alright,
So what you're saying is that if you increase the wing size and dihedral, then you would reduce the sonic booms intensity. But, if you have too much dihedral, then the wing would be angled up too far, thus increasing stall speed, the space needed for T/O, and the lift/thrust needed for T/O. If you increased the amount of thrust, then you would need to be refueled in mid-air/have larger gas tanks. It would also be less noise efficient because you would need more thrust, requiring more/bigger engines. It would also be another fuel guzzler, and the airlines are looking for ways to reduce fuel, not use more of it.
Not trying to shoot you down, just my $0.02
See Ya'll Later!
DAL7e7 is wondering... Do pilots take crash courses?
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 25 Reply 22, posted (7 years 10 months 4 weeks 7 hours ago) and read 4261 times:
The picture above is the simplest concept, IT is not designed to do anything but show itself off. That said, I did make a conceptual airliner but have yet to show off the deatils. I initially planned to post them, I may still.
From my calulations, it is a twin engined plane with by-pass ratio of 1.5. Oddly enough, if one engine went out, at it's max speed of M0.894 it would go the same range as going supersonic M1.592 with both engines, but it would go about 10 % farther at about M1.3 overland supersonic. Either way I think that is spectacular. I did consider all the lift and all the drag. It's (L/D)max was like 8 with an aspect ratio of 5.35.
DAL7e7, you began with assuming 'too much' of something would then throw off the balance and make the plane useless; isn't that obvious? Don't worry, I got a bunch of ideas that have superceeded this one, you'll never rain in on my parade.
We know how airlines are now, what about 20 years from now when this thing should enter service? All trends show an constantly increasing number of pax anually at a rate of 4% and without more bigger planes and/or higher speeds; I see a gridlock. These people will slowly experience more and more waiting and later flights until they will have no where to go. I'm sure someone will realize by then, IMO, it will be too late. We will have a period of the worst commerical aviation experience on record because we think we are at the peak of it all now.
It is like you know you have a lot of money and you make a bunch of big purchases without checking your bank account. Willing to gamble just because you think your purchases are worth while?
We have to start either a supergiant to succeed the A380 (BWB) or a large STOVL airliner or a supersonic within 5-7 years to enter service by 2025 or we are screwed. I vote for sonics as it may be the easiest.
The meaning of life is curiosity; we were put on this planet to explore opportunities.
Kalakaua From United States of America, joined Jan 2004, 1516 posts, RR: 6 Reply 23, posted (7 years 10 months 4 weeks 5 hours ago) and read 4245 times:
Did you know if you crack a whip, you're breaking the sound barrier? Just a little 'fun' fact.
Gravity explains the motions of the planets, but it cannot explain who set the planets in motion.
Klaus From Germany, joined Jul 2001, 20146 posts, RR: 57 Reply 24, posted (7 years 10 months 4 weeks ago) and read 4214 times:
Lehpron: We have to start either a supergiant to succeed the A380 (BWB) or a large STOVL airliner or a supersonic within 5-7 years to enter service by 2025 or we are screwed. I vote for sonics as it may be the easiest.
No, it´s not. It would be difficult, expensive and would make the problems worse on top of that.
Congestion both on the ground and in the air would be much worsened by a larger number of smaller supersonic flights instead of fewer larger planes, even if those are slower. The primary potential for efficiency gains with increasing traffic would be in more efficient airports and in larger planes.
I guess a significant part of Concorde´s speed advantage in practice was in the extra spacious and more highly staffed Concorde gates/lounges when compared to the cheaper mass-transit gates...
Apart from that, supersonic planes only reduce the pure flight time for the passengers; They do nothing against congestion or delays. Quite the opposite (unless they´re jumbo-sized themselves).
I agree that we need further progress, and higher speeds would surely be nice to have. But it´s not an automatic solution by itself.
25 Lehpron: What do you suggest, a 400-500 pax sonic? So merge BWB with this proposed technology, that would become an 80m long x 50 m wide flying wing. Like this
26 DfwRevolution: Cool looking picture... what program did you say you were using? As for a 400 passenger sonic, slow down turbo I'd concentrate on a 70-80 passenger su
27 Greg: Check out this months Popular Science (I think)...the cover story in on 'boomless' supersonic flight.
28 Klaus: Lehpron: What do you suggest, a 400-500 pax sonic? If you really want to address congestion issues, that would probably be a necessity... Lehpron: So
29 DAL7e7: Hey, Also, if you increased dihedral wouldn't the flaps be harder to move, require more oil, and need to be fixed/checked frequently? Plus, would you
30 QantasA332: Also, if you made this plane with a T-tail, then wouldn't that create better lift? I mean, look at the MD-80 series. Don't they get pretty good lift?
31 Lehpron: Thanks Klaus, I might take an interest in "jumbo-sized" sonics even though I see square-cube as an interference in thought. >> "Also, if you increased
32 Auae: ** And second, t-tail designs don't necessarily, in your words, "create better lift." In fact, tail design doesn't really have an effect on the lift o
33 Kalakaua: Hey Lephron. I was wondering if Prof. Doryland and Dr. Felton still teaches at ERAU...
34 DAL7e7: Hey again, In reference to the delta wing, how do those elevators work? Also, wouldn't the dihedral make the elevators less efficient? Also, couldn't
35 QantasA332: But it is important to note that tail position weighs heavily on tail design and performance. For instance, T-tails are not in the downwash of the win
36 Lehpron: Just answering older questions. Cancidas: >>"by the way, are you still at riddle in PRC""Hey Lephron. I was wondering if Prof. Doryland and Dr. Felton
37 DAL7e7: First off, don't steal my phrase Lehpron.*wink wink* I also think I can answer my own question about moving parts. If you used spoilers, like the beec
38 QantasA332: Plus, wingtip fences. Would that work on a supersonic aircraft? Sure it would work - after all, there's no realistic situation where effective aspect
39 777lover: With regards to the very first reply.... The Great Lephron is a little bit of both. I know him personally and he can draw both by hand and on microsof
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