jheadley 0 #1 January 7, 2006 I was at Skyventure Orlando about a week ago, and much to my surprise, it looked like the air actually was sucked into the chamber from the top, rather than blown in from the bottom. Is this correct? Is there any difference in the way the air feels from one that sucks air versus one that blows air? Also, anyone who could hook me up with a job there... you'd be my hero. Quote Share this post Link to post Share on other sites
piisfish 135 #2 January 7, 2006 some suck, some blow.... Just be very careful if you get in tunnels that swallow scissors beat paper, paper beat rock, rock beat wingsuit - KarlM Quote Share this post Link to post Share on other sites
Bodyflight.Net 0 #3 January 7, 2006 there is a definite 'lifting' sensation that I can associate with sucker tunnels.. in a blower.. there is a definite 'push' sensation.. where in say a vertical position, you can certainly feel the loss of air around your face as your lower body blocks it... in the sucker tunnels I've been in it's different, it's as if your being pushed and pulled simultaneously, which can either be attributed to the fact that the walls contain what air should be spilling out over the sides or that the updraft really does create a different environment. either way I feel personally that the blower creates a more realistic 'skydiving freefall' experience for this reason.. I think more will agree with this as well when more familiar vertical references are incorporated and more open air high speed tunnels are created. glad you had fun! Quote Share this post Link to post Share on other sites
Bodyflight.Net 0 #4 January 7, 2006 fish. that's hilarious.. can I turn that into a Tshirt please? Quote Share this post Link to post Share on other sites
VivaHeadDown 0 #5 January 8, 2006 Aerodynamically there is no difference where you place the fan with regaurds to what produces your lift. Either way, the air is rushing up past you, which is what lifts you. However, on the "up" side of the fan, the air is not always as clean because of turbulence caused by the fan blades. So, although the forces are no different, a fan up top creating that flow has the potential to create a more realitic freefall envinonment (because in freefall there is nothing to create bumpy air except your buddy). Many horizontal wind tunnels place the "fan" after the test chamber for the quality of air it produces. The ones that don't typically don't use fans at all, but rather fill up a resevior of high pressure air and then release it into the flight chamber (a blow down tunnel). These are short test periods, but very high speed when enough presure has been built up. A fan placed far enough ahead of the flight chamber has the potential to produce equally clean air as an upper mounted fan, but I don't have any practical experience with those models (just some basic theoretical). In the end I'd recommend not thinking about any of this and just flying your body, you can convince yourself that you feel anything regardless of the actual physics involved. It's been proven that you can learn in a wide variety of environments so have a good time. Quote Share this post Link to post Share on other sites
lisamariewillbe 1 #6 January 8, 2006 QuoteJust be very careful if you get in tunnels that swallow Thats some funny shit... Do any gurgle?Sudsy Fist: i don't think i'd ever say this Sudsy Fist: but you're looking damn sudsydoable in this Quote Share this post Link to post Share on other sites
piisfish 135 #7 January 8, 2006 Quotefish. that's hilarious.. can I turn that into a Tshirt please?only if I get a copy of the T-shirt scissors beat paper, paper beat rock, rock beat wingsuit - KarlM Quote Share this post Link to post Share on other sites
pilotdave 0 #8 January 8, 2006 Blower tunnels used for research usually have a diverging-converging section right before the test section. Expanding the flow then contracting it back down reduces turbulence in it. Screens are also used to reduce turbulence and straighten the flow. "In-draft" (sucker) tunnels are inherently more efficient, but they require long diffusers. When space is limited, blower tunnels can be made much shorter. That's why they make sense for smaller vertical wind tunnels. Tunnels that use pressure resevoirs can also be either "blowers" or "suckers," or even both. I think suckers (using a vacuum chamber) are probably much more common. I got to run a mach 2 tunnel like that once. Only works for about 10 seconds at a time, but it really SUCKED! It was pretty interesting... one end was just open to the room (when the valves were opened). Looked like you could just get sucked right in, but you could just barely feel feel the air in the room moving. The weirdest part was when it'd get shut down, all the noise from the air entering the vacuum chamber would suddenly be able to make it back up through the tunnel. (Sound can't travel backwards through a supersonic flow). Made the strangest sound. Dave Quote Share this post Link to post Share on other sites
Bodyflight.Net 0 #9 January 8, 2006 pm me a shipping address... and I'll do just that.. as soon as I make one anyway Quote Share this post Link to post Share on other sites Shark 0 #10 January 8, 2006 Spoken like a true engineer. Quote Share this post Link to post Share on other sites diablopilot 2 #11 January 8, 2006 Quoteeither way I feel personally that the blower creates a more realistic 'skydiving freefall' experience for this reason.. I think more will agree with this as well when more familiar vertical references are incorporated and more open air high speed tunnels are created. I'd disagree strongly.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites matthewcline 0 #12 January 8, 2006 I think there is a bit of mis-conception with the blowers and suckers (I feel some what like a dirty old man writing that, I mean, I am but, oh never mind back to the point). With the SV designs the intake can be affected by the air flow around the out side of the facility. In the videos this usualy looks like the group is moving up and down in the flight chamber. Gusty wind tends to make the group bob up and down. With the "Blower" designs there appears to be less affect on the flight chamber (as long as it is contained) by the out side air. If the SV models (non-recirculating) had a way of negating the gound wind currents then they would be equal in ability and then cost of design would be the only difference. But I am no designer just a user.An Instructors first concern is student safety. So, start being safe, first!!! Quote Share this post Link to post Share on other sites VivaHeadDown 0 #13 January 9, 2006 The SV design can be affected by outside air in non-recirc ones, but it comes across as turbulence and it takes 30+mph crosswind at the intake before most tunnel rats (sensitive to thier environment as they are) can even notice it. The bobbing up and down is caused by a completely different event (one that newer generation SV tunnels have just about cleaned up and is easily worked around at the older versions if you understand what is causing it). Don't Confuse Me With My Own Words Quote Share this post Link to post Share on other sites diablopilot 2 #14 January 9, 2006 The effects of outside winds on a SV non-recirculating tunnel are not noticable till they exceed 25mph, and then they cause a completly different phenomena than you describe. Most of the vertical movement in the SV -non-recircualting tunnes is flyer induced. Teams often forget about holding levels. Another occurance in the Orlando, and Perris facility (Not sure about AZ) is the ability to "cavitate" a fan. If too large a burble is created against a wall, a fan will loose efficiency, and the over all power drops out. The new facility in the UK and following recirculating designs have elimitated that problem by placing the fan motors at 90 degrees to the airflow in the chamber so flyers burble effects are negated by the time they reach the fans Blower designs will always have the problem of fan burbles in the flight area.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites Bodyflight.Net 0 #15 January 9, 2006 your right about the backpressure I think at one time (SVO pre-upgrade).. the fans when they got backed up would just bog the whole thing down... and everyone in the chamber would drop.. just from the outside wind providing resistance on the exhaust...and I think diablo the mph on the gusts would be relative to the airspeed being used/the speed coming out is fairly slow.. it doesn't take much presure really to inhibit it but the last times I was in SVO they had ample airspeed to make up for it when it would drop..but I'm not a fan of constantly changing speeds..again why I favor an open air blower.. constant speed no fluxuations unless you change them with the controls. I love the idea of one where the cross wind doesn't affect the column.. but isn't wall to wall...maybe like... a huge wind break/fence around the whole thing! certainly would create tons of advertising space still gotta be outside of course Quote Share this post Link to post Share on other sites matthewcline 0 #16 January 9, 2006 Dawn, You could always convince Ben to design the plexi glass walls for the bottom of AAC and maybe 10' above the height of the net out on the outer wall. No outside influence buut still out side. Diablo, Maybe I didn't understand it when it happened, but I was watching Majik in SVO (2002 I think, maybe, I am getting old) and they had the same bobbing up and down issue that us lesser mortals had in the tunnel. It was a bit windy out side (hurricane had broke up to thunderstorm from skydiver hell). that is why I figured it to be the outside air influence and not just the bodies, but I do understand the bodies burble and how they can effect the tunnels lifting ability. But hey, Tunnels are a great tool and toy! It just depends on the mind set I think.An Instructors first concern is student safety. So, start being safe, first!!! Quote Share this post Link to post Share on other sites johng3592 0 #17 February 27, 2006 Quote Another occurance in the Orlando, and Perris facility (Not sure about AZ) is the ability to "cavitate" a fan. If too large a burble is created against a wall, a fan will loose efficiency, and the over all power drops out. The new facility in the UK and following recirculating designs have elimitated that problem by placing the fan motors at 90 degrees to the airflow in the chamber so flyers burble effects are negated by the time they reach the fans Blower designs will always have the problem of fan burbles in the flight area. Actually, if you apply the theory of the first para to the second, you have a solution. Locate the blower fans remotely enough, like around a 90 deg curve, and you don't see 'burble effects'. - And world champion 4-way folks say they feel the difference between suck & blow when doing vertical transitions. Quote Share this post Link to post Share on other sites Bodyflight.Net 0 #18 February 27, 2006 Very impressive! Quote Share this post Link to post Share on other sites diablopilot 2 #19 February 27, 2006 QuoteLocate the blower fans remotely enough, like around a 90 deg curve, and you don't see 'burble effects'. True enough, and tha't what the new SkyVenture recirculating type have done, but the fans are still on the "downstream" side (i.e. after the chamber). Quote- And world champion 4-way folks say they feel the difference between suck & blow when doing vertical transitions. And what tunnels are they doing thes transitions in?---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites Paulipod 0 #20 February 27, 2006 Quotebut the fans are still on the "downstream" side (i.e. after the chamber). That wholly depends on your point of view - stricly speaking they are also upstream of the chamber... Only difference is the number of turning vanes to meet on the way - and an expansion area. In scientific tunnels you will never find a test section (flight chamber in our case) that does not have some kind of filtering/straightening of the air after the fans. Our needs for quality are not quite as high as science facilities obviously. Its all about what you do with the air after it has been chopped and swirled by blades. In skyventures case this is turn it a few times / expand it and contract it. I would hate to use the word 'blower' becuase they suck and blow in a re-circ... so lets just say this could be done the same if the fans were at floor level rather than mounted high Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites peaceskydiver 0 #21 March 3, 2006 that is really funny. spoken like a true engineer- i was thinking that as well b/c i am a mechanical engineer with minor in aerospace. glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. co workers always tell me, you desgin perfectly good airplanes, why are you jumping out of them?? sooo... i bought a shirt from go-wear.com that says "jumps from perfectly good airplanes" -that should really rub it in!!! PEACE!!! christi "From Wings Came Flight" Quote Share this post Link to post Share on other sites airgord 1 #22 March 8, 2006 Geeks, all ya'll. Quote Share this post Link to post Share on other sites Zenister 0 #23 March 8, 2006 Quote glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. wow thats got to be an anomoly.. you cant swing a dead cat (or a live one) at Eloy without hitting an Engineer...____________________________________ Those who fail to learn from the past are simply Doomed. Quote Share this post Link to post Share on other sites SkymonkeyONE 3 #24 March 8, 2006 QuoteQuote glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. wow thats got to be an anomoly.. you cant swing a dead cat (or a live one) at Eloy without hitting an Engineer... Or a convicted felon! Quote Share this post Link to post Share on other sites Zenister 0 #25 March 8, 2006 QuoteQuoteQuote glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. wow thats got to be an anomoly.. you cant swing a dead cat (or a live one) at Eloy without hitting an Engineer... Or a convicted felon! sometimes both with the same cat.. ____________________________________ Those who fail to learn from the past are simply Doomed. Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. 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Shark 0 #10 January 8, 2006 Spoken like a true engineer. Quote Share this post Link to post Share on other sites
diablopilot 2 #11 January 8, 2006 Quoteeither way I feel personally that the blower creates a more realistic 'skydiving freefall' experience for this reason.. I think more will agree with this as well when more familiar vertical references are incorporated and more open air high speed tunnels are created. I'd disagree strongly.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
matthewcline 0 #12 January 8, 2006 I think there is a bit of mis-conception with the blowers and suckers (I feel some what like a dirty old man writing that, I mean, I am but, oh never mind back to the point). With the SV designs the intake can be affected by the air flow around the out side of the facility. In the videos this usualy looks like the group is moving up and down in the flight chamber. Gusty wind tends to make the group bob up and down. With the "Blower" designs there appears to be less affect on the flight chamber (as long as it is contained) by the out side air. If the SV models (non-recirculating) had a way of negating the gound wind currents then they would be equal in ability and then cost of design would be the only difference. But I am no designer just a user.An Instructors first concern is student safety. So, start being safe, first!!! Quote Share this post Link to post Share on other sites
VivaHeadDown 0 #13 January 9, 2006 The SV design can be affected by outside air in non-recirc ones, but it comes across as turbulence and it takes 30+mph crosswind at the intake before most tunnel rats (sensitive to thier environment as they are) can even notice it. The bobbing up and down is caused by a completely different event (one that newer generation SV tunnels have just about cleaned up and is easily worked around at the older versions if you understand what is causing it). Don't Confuse Me With My Own Words Quote Share this post Link to post Share on other sites
diablopilot 2 #14 January 9, 2006 The effects of outside winds on a SV non-recirculating tunnel are not noticable till they exceed 25mph, and then they cause a completly different phenomena than you describe. Most of the vertical movement in the SV -non-recircualting tunnes is flyer induced. Teams often forget about holding levels. Another occurance in the Orlando, and Perris facility (Not sure about AZ) is the ability to "cavitate" a fan. If too large a burble is created against a wall, a fan will loose efficiency, and the over all power drops out. The new facility in the UK and following recirculating designs have elimitated that problem by placing the fan motors at 90 degrees to the airflow in the chamber so flyers burble effects are negated by the time they reach the fans Blower designs will always have the problem of fan burbles in the flight area.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
Bodyflight.Net 0 #15 January 9, 2006 your right about the backpressure I think at one time (SVO pre-upgrade).. the fans when they got backed up would just bog the whole thing down... and everyone in the chamber would drop.. just from the outside wind providing resistance on the exhaust...and I think diablo the mph on the gusts would be relative to the airspeed being used/the speed coming out is fairly slow.. it doesn't take much presure really to inhibit it but the last times I was in SVO they had ample airspeed to make up for it when it would drop..but I'm not a fan of constantly changing speeds..again why I favor an open air blower.. constant speed no fluxuations unless you change them with the controls. I love the idea of one where the cross wind doesn't affect the column.. but isn't wall to wall...maybe like... a huge wind break/fence around the whole thing! certainly would create tons of advertising space still gotta be outside of course Quote Share this post Link to post Share on other sites
matthewcline 0 #16 January 9, 2006 Dawn, You could always convince Ben to design the plexi glass walls for the bottom of AAC and maybe 10' above the height of the net out on the outer wall. No outside influence buut still out side. Diablo, Maybe I didn't understand it when it happened, but I was watching Majik in SVO (2002 I think, maybe, I am getting old) and they had the same bobbing up and down issue that us lesser mortals had in the tunnel. It was a bit windy out side (hurricane had broke up to thunderstorm from skydiver hell). that is why I figured it to be the outside air influence and not just the bodies, but I do understand the bodies burble and how they can effect the tunnels lifting ability. But hey, Tunnels are a great tool and toy! It just depends on the mind set I think.An Instructors first concern is student safety. So, start being safe, first!!! Quote Share this post Link to post Share on other sites
johng3592 0 #17 February 27, 2006 Quote Another occurance in the Orlando, and Perris facility (Not sure about AZ) is the ability to "cavitate" a fan. If too large a burble is created against a wall, a fan will loose efficiency, and the over all power drops out. The new facility in the UK and following recirculating designs have elimitated that problem by placing the fan motors at 90 degrees to the airflow in the chamber so flyers burble effects are negated by the time they reach the fans Blower designs will always have the problem of fan burbles in the flight area. Actually, if you apply the theory of the first para to the second, you have a solution. Locate the blower fans remotely enough, like around a 90 deg curve, and you don't see 'burble effects'. - And world champion 4-way folks say they feel the difference between suck & blow when doing vertical transitions. Quote Share this post Link to post Share on other sites
Bodyflight.Net 0 #18 February 27, 2006 Very impressive! Quote Share this post Link to post Share on other sites
diablopilot 2 #19 February 27, 2006 QuoteLocate the blower fans remotely enough, like around a 90 deg curve, and you don't see 'burble effects'. True enough, and tha't what the new SkyVenture recirculating type have done, but the fans are still on the "downstream" side (i.e. after the chamber). Quote- And world champion 4-way folks say they feel the difference between suck & blow when doing vertical transitions. And what tunnels are they doing thes transitions in?---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
Paulipod 0 #20 February 27, 2006 Quotebut the fans are still on the "downstream" side (i.e. after the chamber). That wholly depends on your point of view - stricly speaking they are also upstream of the chamber... Only difference is the number of turning vanes to meet on the way - and an expansion area. In scientific tunnels you will never find a test section (flight chamber in our case) that does not have some kind of filtering/straightening of the air after the fans. Our needs for quality are not quite as high as science facilities obviously. Its all about what you do with the air after it has been chopped and swirled by blades. In skyventures case this is turn it a few times / expand it and contract it. I would hate to use the word 'blower' becuase they suck and blow in a re-circ... so lets just say this could be done the same if the fans were at floor level rather than mounted high Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
peaceskydiver 0 #21 March 3, 2006 that is really funny. spoken like a true engineer- i was thinking that as well b/c i am a mechanical engineer with minor in aerospace. glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. co workers always tell me, you desgin perfectly good airplanes, why are you jumping out of them?? sooo... i bought a shirt from go-wear.com that says "jumps from perfectly good airplanes" -that should really rub it in!!! PEACE!!! christi "From Wings Came Flight" Quote Share this post Link to post Share on other sites
airgord 1 #22 March 8, 2006 Geeks, all ya'll. Quote Share this post Link to post Share on other sites
Zenister 0 #23 March 8, 2006 Quote glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. wow thats got to be an anomoly.. you cant swing a dead cat (or a live one) at Eloy without hitting an Engineer...____________________________________ Those who fail to learn from the past are simply Doomed. Quote Share this post Link to post Share on other sites
SkymonkeyONE 3 #24 March 8, 2006 QuoteQuote glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. wow thats got to be an anomoly.. you cant swing a dead cat (or a live one) at Eloy without hitting an Engineer... Or a convicted felon! Quote Share this post Link to post Share on other sites
Zenister 0 #25 March 8, 2006 QuoteQuoteQuote glad to see some engineers in the skydiving sport b/c i don't know any of them here in new york. wow thats got to be an anomoly.. you cant swing a dead cat (or a live one) at Eloy without hitting an Engineer... Or a convicted felon! sometimes both with the same cat.. ____________________________________ Those who fail to learn from the past are simply Doomed. Quote Share this post Link to post Share on other sites
