cgross 1 #1 November 20, 2002 I am not sure if anyone knows, but I was wondering how much it cost to build and operate a wind tunnel. In my opinion, there aren't enough of them around. I think it would be great thing to have here in the North east where the winter days are short, cold and snowy. Hey maybe i'll put in for one. I am guessing they can not be too much to build ( a doppler radar is only about 1.5 million), but maybe the cost to operate is high. Any ideas???? Quote Share this post Link to post Share on other sites
ladyskydiver 0 #2 November 20, 2002 From what I heard, the problem with building a tunnel in the wonderful north is the fact that the tunnels pump air in from outside and circulate that air. Don't know how many people would love to have that cold air pumped inside to jump in. I could be wrong, but that's what I heard was the reason a wind tunnel didn't get built in Chicago.Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile. Quote Share this post Link to post Share on other sites
freeflyz 0 #3 November 20, 2002 About 1.5 mil more or less and the cost of the land it's going to be on! Quote Share this post Link to post Share on other sites
cgross 1 #4 November 20, 2002 I can understand that, but; the surface temps in most cases are warmer than the temps at 13.5, so I would do a tunnel in the cold rather than jump in the cold anyday. Maybe it's that wuffo's wouldn't do a tunnel in the cold, and there are not enough jumpers to maintane proffit fo rthe tunnel. Quote Share this post Link to post Share on other sites
PhreeZone 20 #5 November 20, 2002 1.5 mil seems to be the number a lot of places toss around. And there is one now in Orlando, one soon in CA, AZ and possibly other sites. Up north heating the air to make it worthwhile would drive the cost up too much for normal usage.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
weid14 0 #6 November 20, 2002 Quote 1.5 mil seems to be the number a lot of places toss around. And there is one now in Orlando, one soon in CA, AZ and possibly other sites. Up north heating the air to make it worthwhile would drive the cost up too much for normal usage. OK I actaully have looked into putting one in the northeast. There are recircualtion systems, and it actually is not bad because the heating requirements for the building go down, but that is a small cost. You're in the neighborhood of 3.5 million to purchase and install, with a land lease. Prime property is very expensive. Ideally I would build it by six flags in NJ. There are competing companies with ideas in the Trenton area also. The one designed for the UK is a recirculation system. Remeber, there is a lot of air moving, but not much pressure, so the structural design isnt' that much out of the ordinary. Quote Share this post Link to post Share on other sites
DJL 235 #7 November 20, 2002 Recirculating wouldn't be that complicated. I'm bored at work right now and this does appear to be an engineering office I work for so...I'll design one real quick. Ok, I'm not going to go any further than selecting fans, the recirculation, and the chamber... I'm just interested in seeing what kind of hardware is involved. -doug"I encourage all awesome dangerous behavior." - Jeffro Fincher Quote Share this post Link to post Share on other sites
Muenkel 0 #8 November 20, 2002 Wind Tunnels are the creation of the devil. Stay away. _________________________________________ Chris Quote Share this post Link to post Share on other sites
pilotdave 0 #9 November 20, 2002 Recirculating, or "closed return" wind tunnels are more efficient than "open return" tunnels. The momentum of the air helps keep it flowing around the tunnel so the fans don't have to do quite as much work. Most "real" wind tunnels are closed return for this reason (and better air quality, etc). The vertical tunnels don't care nearly as much about air quality (turbulence, debris) as tunnels being used for research, so I guess they all decided to go with a cheaper construction cost. The diffuser (the part of the tunnel above the flying area) would probably have to be pretty tall which could be a problem. For a really efficient tunnel, the largest section, where the fans are, has to be much much bigger than the flying area, which is the smallest part of the tunnel. I think it would be really cool to see a vertical wind tunnel that's really made "right" as far as conventional wind tunnel standards go. Dave Quote Share this post Link to post Share on other sites
cgross 1 #10 November 20, 2002 Why chris???? Why did the devil play a hand in the creation of the tunnel? Quote Share this post Link to post Share on other sites
wmw999 2,560 #11 November 20, 2002 Quote (lotsa stuff) You are an engineer, aren't you? Wendy W.There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown) Quote Share this post Link to post Share on other sites
Muenkel 0 #12 November 20, 2002 Quote Why chris???? Why did the devil play a hand in the creation of the tunnel? Let's just say that the tunnel doesn't like me too much and leave it at that. _________________________________________ Chris Quote Share this post Link to post Share on other sites
cgross 1 #13 November 20, 2002 awww did somebody bump their head? Quote Share this post Link to post Share on other sites
Muenkel 0 #14 November 20, 2002 Quote awww did somebody bump their head? 6 year old girls were doing a better job in there than I was. _________________________________________ Chris Quote Share this post Link to post Share on other sites
cgross 1 #15 November 20, 2002 Well, I can't make fun of you, because I am a Tunnel virgin, but I am sure i will eventually get to one. I will post you on my progress. Stupid Wuffo comment: How hard can it be? You're just falling! Quote Share this post Link to post Share on other sites
pilotdave 0 #16 November 20, 2002 Quote You are and engineer, aren't you? Pretending to be till May. Then I'll graduate and be a real rocket scientist. Eh, it's no brain surgery. Dave Quote Share this post Link to post Share on other sites
DJL 235 #17 November 20, 2002 For a 12 ft Diameter wind tunnel @ 120mph, 1" static pressure for the sake of filling the blank on my little program...need about 1,193,702 cubic ft per minute (cfm) = 15 - propeller fans (6 ft dia) cranking 80,000 cfm each, each fan costs $13,000 (195,000), operating cost 5,632/yr ($84,480/yr). This is a VERY rough estimate but it gives you an idea of what just the fans cost for Harry homeowner to slap one together. I think the best location for the fans is on the recirculation side blowing down. That way you don't have to make the thing so tall and the motors could be easily accessible within the structure for maintenance and repair. -doug"I encourage all awesome dangerous behavior." - Jeffro Fincher Quote Share this post Link to post Share on other sites
freeflir29 0 #18 November 20, 2002 The info I got from Skyventure is anywhere from $950,000 to $2.5M to build the tunnel. Depending on how big you want it. Of course this doesn't include the land and they want about $10,000 per month in "royalties." Now....if I just had $500,000 to get the loan process started I'd be good. Quote Share this post Link to post Share on other sites
Scoby 0 #19 November 20, 2002 Quote operating cost 5,632/yr ($84,480/yr). What kind of duty cycle is that? Or is that for a year of continuous operation? Quote Share this post Link to post Share on other sites
weid14 0 #20 November 20, 2002 Quote For a 12 ft Diameter wind tunnel @ 120mph, 1" static pressure for the sake of filling the blank on my little program...need about 1,193,702 cubic ft per minute (cfm) = 15 - propeller fans (6 ft dia) cranking 80,000 cfm each, each fan costs $13,000 (195,000), operating cost 5,632/yr ($84,480/yr). This is a VERY rough estimate but it gives you an idea of what just the fans cost for Harry homeowner to slap one together. I think the best location for the fans is on the recirculation side blowing down. That way you don't have to make the thing so tall and the motors could be easily accessible within the structure for maintenance and repair. -doug what type of fan? you're going to get more of a pressure loss in the ducting than that (well, unless you want the ducting to be gigundous). the tunnels are basically an upright venturi (you did model it as such, right?). the flying chamber being the throat. the right kind of fans to use are the type that exhaust subways (or similar would be a cooling tower). actully a cooling tower's fan design would be a fairly close approximatino. now, don't forget that you also need to have quick release air dumps on the fan inlet also to keep everyone a little safer in there. Quote Share this post Link to post Share on other sites
cgross 1 #21 November 20, 2002 Well, if you ran that thing 5 days aweek for 6 hrs for 1 yr at a rate of $400 per hour (I don't how much other places charge) That will give you around 600K. A little profit, and some payment on your loan. 1,500,000 purchase 120,000 land lease 85,000 operating cost 100,000 Employees/ insurance etc (Underestimate) ------------- 1.8mil to start. You could pay off the loan in 10yrs Quote Share this post Link to post Share on other sites
weid14 0 #22 November 20, 2002 Quote Well, if you ran that thing 5 days aweek for 6 hrs for 1 yr at a rate of $400 per hour (I don't how much other places charge) That will give you around 600K. I can send you the spreadsheet I have if you would like, those numbers are seriously lowA little profit, and some payment on your loan. 1,500,000 purchase 120,000 land lease 85,000 operating cost 100,000 Employees/ insurance etc (Underestimate) ------------- 1.8mil to start. You could pay off the loan in 10yrs Quote Share this post Link to post Share on other sites
pilotdave 0 #23 November 20, 2002 Quote I think the best location for the fans is on the recirculation side blowing down. That way you don't have to make the thing so tall and the motors could be easily accessible within the structure for maintenance and repair. Yep, thats just how i'd picture it. Exactly like a horizontal wind tunnel on its side. You should see how many i've sketched in the margins of notebooks when i've been bored in class. My school has an 8 x 11 foot horizontal wind tunnel. It uses one very large electric motor and single fan. I think it's somewhere around 20 feet in diameter. It does about 230 mph max. See This for a diagram. Now lets just flip that on it's side and we're set! One of my former profs used to run NASA Ames' huge wind tunnel. 80' by 120' test section, and gets up to about 120 mph. http://windtunnels.arc.nasa.gov/WindTunnels/nfac80120.html Figure out how to build that sideways and you could be doing big ways! Dave Dave Quote Share this post Link to post Share on other sites
DJL 235 #24 November 20, 2002 Cook axial propeller fans. These are right off the shelf. I'm looking at plenum fans now, they have a lower first cost. -doug"I encourage all awesome dangerous behavior." - Jeffro Fincher Quote Share this post Link to post Share on other sites
weid14 0 #25 November 20, 2002 The trouble with one fan is pressure drop along the walls. you actually need to get the velocity along the walls higher than the middle to overcome surface drag. thats why multiple fans with variable frequency drives. Quote Share this post Link to post Share on other sites
