napalmboy 0 #26 February 24, 2006 Quote DOESN'T ANYONE TAKE COMPUTATIONAL FLUID DYNAMICS ANYMORE!!!!!????! Are you kidding? I didn't even want to take Itermediate Mechanics...that tensor stuff is scary. Well, the door was open... Quote Share this post Link to post Share on other sites
billvon 2,427 #27 February 24, 2006 >This is assuming no wind. Yes. When there is wind, the jumpers match the horizontal speed of the wind in about the same amount of time (barring tracking, sudden windshears etc.) Quote Share this post Link to post Share on other sites
kelpdiver 2 #28 February 24, 2006 Quote A human weighing 180 lbs traveling at 26.82 meters/sec (60mph) decelerates to zero meters per second in 2 feet. (landing on two mattresses under partial inflated canopy) Force exerted on the body: 43,353.75 lbs, or 5.41 tons. (the force of a 15mph car crash with no seatbelt) Painful yes, but Survivable… This is less than 1/100 the force of going in at full speed with no cushion. hell, if the numbers pan out, Jeb has his answer. Just line the LZ with a bunch of mattresses - that's got to cost less than millions. (or do the wingsuit folk only get that 60mph fall rate when coupled with a substantial horizonal speed component?) Quote Share this post Link to post Share on other sites
ZigZagMarquis 8 #29 February 24, 2006 QuoteQuote DOESN'T ANYONE TAKE COMPUTATIONAL FLUID DYNAMICS ANYMORE!!!!!????! Are you kidding? I didn't even want to take Itermediate Mechanics...that tensor stuff is scary. eh, sorry, its kinda a requirement for us Aeronautical Engineer types... Software Engineer types only need to know that when fluids get into the hardware their software is running on... their software quits at the same time as does the hardware... that's why your computer doesn't work well after spilling a beer on it. Quote Share this post Link to post Share on other sites
dontbounce 0 #30 February 24, 2006 QuoteDOESN'T ANYONE TAKE PHYSICS IN HIGH-SCHOOL ANYMORE!!!!????! Never went to high school.. Dropped out in the 7th grade. 4 yrs U.S. Army, 3 Associates Degrees, Bachelor of Management, Microsoft Certified Systems Engineer, Cisco Certified Network Associate. Need a firewall that will keep out the best hackers in the world while allowing 100,000 users to surf the web? I'm your man. Calculate the area of y=x squared from x=0 to x=1? I remember it is .333 but doing it on paper? Yeah... Not since 1992, jacko. Business Calculus, Matrices and Linear Programming, Chemistry, Programming, Network Engineering, thats all. Doesnt help me much here. Your point is? Quote Share this post Link to post Share on other sites
dontbounce 0 #31 February 24, 2006 QuoteQuote A human weighing 180 lbs traveling at 26.82 meters/sec (60mph) decelerates to zero meters per second in 2 feet. (landing on two mattresses under partial inflated canopy) Force exerted on the body: 43,353.75 lbs, or 5.41 tons. (the force of a 15mph car crash with no seatbelt) Painful yes, but Survivable… This is less than 1/100 the force of going in at full speed with no cushion. hell, if the numbers pan out, Jeb has his answer. Just line the LZ with a bunch of mattresses - that's got to cost less than millions. (or do the wingsuit folk only get that 60mph fall rate when coupled with a substantial horizonal speed component?) The Mattresses arent a good real world example, because for the equation to actually work, deceleration must be constant and uniform, which it wouldnt be on a mattress. On an airbag it would be though... That is the goal of Airbag designers; to design an airbag that creates the most linear deceleration possible (spread the shock uniformly over a 18 inch distance) by allowing it to deflate at a predetermined speed. That way you dont have 10 Gs of deceleration for the first 17.5 inches and then 700 Gs in the last 1/2 inch(no airbag), it is more like 25 Gs for the entire 18 inches (with airbag). The most trauma the body will experience is 25Gs, instead of 700Gs. A mattress is just the first thing that came to my head. I actually did this as a kid (jumped from the roof of my dads toolshed to an old mattress) many many times, thats probably why. I recall that "missing the mattress" and landing in the dirt was a serious problem, because your ankles and feet would hurt for days and you wouldnt be able to jump with the rest of the gang for a week or so. On the mattress, you could jump 10 or 30 times before it was time for dinner. This is how stuntmen can jump from a 10 story building onto a 4 ft thick "airbag". It deflates rapidly, and he lands flat on his back. By the time he hits the bottom of the bag, he is almost completely stopped and he suffers little to no shock. Quote Share this post Link to post Share on other sites
Eule 0 #32 February 24, 2006 QuoteTry my freefall simulator at www.iit.edu/~kallend/skydive/ $ ./freefall.exe -bash: ./freefall.exe: cannot execute binary file $ Dang. EulePLF does not stand for Please Land on Face. Quote Share this post Link to post Share on other sites
phoenixlpr 0 #33 February 24, 2006 You have an almost bulletproof rule. Quote Share this post Link to post Share on other sites
kallend 1,647 #34 February 24, 2006 QuoteQuoteTry my freefall simulator at www.iit.edu/~kallend/skydive/ $ ./freefall.exe -bash: ./freefall.exe: cannot execute binary file $ Dang. Eule Works for me. Try the java version.... 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
