kallend 1,648 #1 May 31, 2011 flightaware.com/photos/view/214936-e22ce4ddae476fca6475ffea0e8ad07ff82de937/staffpicksweek/sort/date/page/1 Anyone that doesn't believe there's a region of low pressure above a lifting wing should take a look.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
warpedskydiver 0 #2 May 31, 2011 I have seen the effect from an oncoming B1B that was screaming across a lake. Man did that make some waves. It was high subsonic and not there for long. Quote Share this post Link to post Share on other sites
Calvin19 0 #3 May 31, 2011 that is an example of Prandtl–Glauert singularity, actually it is pretty common. Who does not believe there is low pressure above a flying wing? sounds like something apollo hoaxers and 9/11 truthers would believe. -SPACE- Quote Share this post Link to post Share on other sites
Remster 24 #4 May 31, 2011 Quotesounds like something apollo hoaxers and 9/11 truthers would believe. Good thing there's none of those around here either!Remster Quote Share this post Link to post Share on other sites
popsjumper 2 #5 May 31, 2011 Photographer sucks...all blurry....can't even focus a camera. My reality and yours are quite different. I think we're all Bozos on this bus. Falcon5232, SCS8170, SCSA353, POPS9398, DS239 Quote Share this post Link to post Share on other sites
kallend 1,648 #6 May 31, 2011 Quote Photographer sucks...all blurry....can't even focus a camera. Could be your eyes!... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
popsjumper 2 #7 May 31, 2011 Could be you're right! Then on the other hand, it could be that madly swirling dirty air doesn't hold still for portraits. My reality and yours are quite different. I think we're all Bozos on this bus. Falcon5232, SCS8170, SCSA353, POPS9398, DS239 Quote Share this post Link to post Share on other sites
Calvin19 0 #8 May 31, 2011 Quote Could be you're right! Then on the other hand, it could be that madly swirling dirty air doesn't hold still for portraits. I think it is thermal lensing, or density-gradient lensing. Quote Share this post Link to post Share on other sites
skydiver30960 0 #9 May 31, 2011 Quote Quote Could be you're right! Then on the other hand, it could be that madly swirling dirty air doesn't hold still for portraits. I think it is thermal lensing, or density-gradient lensing. It's an AN-2. Elvisio "hate me, I deserve it" Rodriguez Quote Share this post Link to post Share on other sites
shropshire 0 #10 May 31, 2011 It's a great picture and that's good enough for me.... faith is the way (.)Y(.) Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome Quote Share this post Link to post Share on other sites
popsjumper 2 #11 May 31, 2011 Quote It's a great picture and that's good enough for me.... faith is the way It is and me, too. 'Twas dry American humor, Shroppy.My reality and yours are quite different. I think we're all Bozos on this bus. Falcon5232, SCS8170, SCSA353, POPS9398, DS239 Quote Share this post Link to post Share on other sites
kallend 1,648 #12 June 1, 2011 Quote It's a great picture and that's good enough for me.... faith is the way Actually it's a picture of boobies. It only looks like a B1B on account of thermal lensing and the Prandtl-Glauert effect.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
aeroflyer 0 #13 June 2, 2011 Transonic aerodynamics is a very cool area of study. Did you know that past Mach I the controls in an aircraft can reverse due to a shifting of the aerodynamic center behind the center of gravity? Wrecked havoc on pilots trying to break the barrier because they pulled up and went down Quote Share this post Link to post Share on other sites
kallend 1,648 #14 June 2, 2011 Quote Transonic aerodynamics is a very cool area of study. Did you know that past Mach I the controls in an aircraft can reverse due to a shifting of the aerodynamic center behind the center of gravity? Wrecked havoc on pilots trying to break the barrier because they pulled up and went down As a matter of fact I did know that. It's the kind of thing an engineering professor picks up during the course of a long career.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
warpedskydiver 0 #15 June 2, 2011 Which student told you? Quote Share this post Link to post Share on other sites
JackC1 0 #16 June 2, 2011 Quote Quote Transonic aerodynamics is a very cool area of study. Did you know that past Mach I the controls in an aircraft can reverse due to a shifting of the aerodynamic center behind the center of gravity? Wrecked havoc on pilots trying to break the barrier because they pulled up and went down As a matter of fact I did know that. It's the kind of thing an engineering professor picks up during the course of a long career. I read a book where Chuck Yeager said that was bollocks, made famous by the plot of a 1952 film by David Lean called Breaking the Sound Barrier and somehow making it into urban myth. Quote "Chuck, " he says, "do you mind if I ask you something? Is it true that you broke the sound barrier by reversing the controls? " Yeager is stunned by this. The Secretary—the Secretary! —of the U. S. Air Force! "No, sir, " he says, "that is… not correct. Anyone who reversed the controls going transonic would be dead. " Apparently control reversal is mostly down a lack of torsional rigidity in the wings so that air pressing on the aileron flexes the wing thereby counteracting the input from the pilot. But what do I know. Quote Share this post Link to post Share on other sites
billvon 2,434 #17 June 2, 2011 >Did you know that past Mach I the controls in an aircraft can reverse due >to a shifting of the aerodynamic center behind the center of gravity? > Wrecked havoc on pilots trying to break the barrier because they pulled >up and went down Controls surfaces at transsonic speeds work just like they do at subsonic speeds. But often the shock wave will travel down the wing and park itself over the control surface, and that will make it nearly impossible to move the control surface in the way the pilot wants (or it will flutter and cause all sorts of havoc.) Also, flexible wings will sometimes be so flexible that an aileron deflection downwards will result in the entire wing twisting trailing-edge-down resulting in a roll towards the low elevator. (Note that this is how some aircraft fly to begin with; a small aileron "warps" a larger aileron in the opposite direction, and thus a low elevator on a wing causes that wing to drop. not rise.) However, that's not unique to transsonic flight; the B-47 has such flexible wings that it was a problem well below the speed of sound. Also, I have never heard of a control-reversal problem that affected the horizontal stabilizer/elevator to the degree that "they pulled up and went down." (Other than stalling either the wing or the tailplane.) You may have heard of problems with elevators like the P-38 Lightning had, where turbulence across the tail at very high speeds made it hard to pull out of steep dives. That wasn't control reversal though, it was loss of control due to airflow interference. Quote Share this post Link to post Share on other sites
Calvin19 0 #18 June 2, 2011 Quote Transonic aerodynamics is a very cool area of study. Did you know that past Mach I the controls in an aircraft can reverse due to a shifting of the aerodynamic center behind the center of gravity? Wrecked havoc on pilots trying to break the barrier because they pulled up and went down Kinda... I don't think it is as simple as "reverse". You slipped 'can reverse' in there instead of 'reverse'. The supersonic flow makes a wave that changes the air density so drastically that it can push on different parts of wings and surfaces. I understand trans/supersonic aerodynamics as 'planing' through a fluid, like a boat on a lake. But I'm no aerodynamocologist, just an guy with toys wanting bigger toys. Quote Share this post Link to post Share on other sites
1969912 0 #19 June 3, 2011 Didn't want to start a thread for this, but it's a cool picture from: http://www.nytimes.com/2011/06/02/science/space/02shuttle.html "Once we got to the point where twenty/something's needed a place on the corner that changed the oil in their cars we were doomed . . ." -NickDG Quote Share this post Link to post Share on other sites
shropshire 0 #20 June 3, 2011 Quote Didn't want to start a thread for this, but it's a cool picture from: http://www.nytimes.com/2011/06/02/science/space/02shuttle.html R.I.P (.)Y(.) Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome Quote Share this post Link to post Share on other sites
popsjumper 2 #21 June 3, 2011 I don't think the Wright Bros., and others of their time, had any idea what all that was leading to.My reality and yours are quite different. I think we're all Bozos on this bus. Falcon5232, SCS8170, SCSA353, POPS9398, DS239 Quote Share this post Link to post Share on other sites
shropshire 0 #22 June 3, 2011 It's phenomenal what we've achieved is such a short period (.)Y(.) Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome Quote Share this post Link to post Share on other sites
piisfish 135 #23 June 3, 2011 Quote It's phenomenal what we've achieved is such a short period like sending men to the moon before the first paraglider flight ? scissors beat paper, paper beat rock, rock beat wingsuit - KarlM Quote Share this post Link to post Share on other sites
shropshire 0 #24 June 3, 2011 Quote Quote It's phenomenal what we've achieved is such a short period like sending men to the moon before the first paraglider flight ? Bwhaaaa .... git (p.s - they NEVER wen to the moon) (.)Y(.) Chivalry is not dead; it only sleeps for want of work to do. - Jerome K Jerome Quote Share this post Link to post Share on other sites
aeroflyer 0 #25 June 3, 2011 With regard to the control reversal I'm just repeating what I've been taught obviously I haven't experienced it first hand... Quote Share this post Link to post Share on other sites
