HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 25, 2010, 12:49 AM
In Foam We Trust
Aerogance's Avatar
United States, CA, Ventura County
Joined Sep 2008
2,797 Posts
Cool
Mach Calculator

Check this out:

http://exploration.grc.nasa.gov/educ...ket/machu.html

Weldon = 3400 feet altitude.
Speed of sound = 752mph.
John flew 445mph.
Mach = 0.591.

True Air Speed @ Top of hill = 445mph + 55mph gust = 500mph.
Mach = 0.664.

Wave drag is non-negligible @ Mach 0.7+
Assuming 65mph windspeed:
Mach 0.7 = 527mph
527mph - 65mph = 462mph

462mph is a "soft limit" for gliders with non-supercritical airfoils/surfaces/fusulages etc. It is likely that with the K100 this soft limit will be reached this year assuming its airfoil is good to Mach 0.7.

If a suitable supercritical airfoil can be developed that can push this limit up to Mach 0.85:
Mach 0.85 = 640mph
Assumed wind speed = 75mph
640mph - 75mph = 565mph top "radar" speed.

Interesting realm we find ourselves pushing into.
Aerogance is offline Find More Posts by Aerogance
Last edited by Aerogance; May 25, 2010 at 12:59 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old May 25, 2010, 06:28 AM
Mach 0.261 ... Hiccup of Wiggy
Geo420's Avatar
Wiggy Poo, England!
Joined Mar 2006
1,258 Posts
Cool... just worked out my mach speed...
Not very impressive!
But hey, work down the street, stop anyone, ask them for their Mach no...



Regards
George
Geo420 is offline Find More Posts by Geo420
Reply With Quote
Old May 25, 2010, 06:36 AM
Registered User
Joined Jul 2006
119 Posts
Quote:
Originally Posted by Geo420 View Post
Cool... just worked out my mach speed...
Not very impressive!
But hey, work down the street, stop anyone, ask them for their Mach no...



Regards
George
Go on then, Walk down the street and knock on my door and ask me
adam_lambretta is offline Find More Posts by adam_lambretta
Reply With Quote
Old May 25, 2010, 07:09 AM
Mach 0.261 ... Hiccup of Wiggy
Geo420's Avatar
Wiggy Poo, England!
Joined Mar 2006
1,258 Posts
er Adam, whats your mach then doood?
Geo420 is offline Find More Posts by Geo420
Reply With Quote
Old May 16, 2011, 04:25 AM
In Foam We Trust
Aerogance's Avatar
United States, CA, Ventura County
Joined Sep 2008
2,797 Posts
My prediction came true, odd looking back!
Aerogance is offline Find More Posts by Aerogance
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Idea Yet another CG Calculator Montag DP Modeling Science 103 Mar 27, 2014 01:14 AM
Wanted Mach 1 and Mach None kits gavoss Aircraft - Fuel - Airplanes (FS/W) 2 Apr 17, 2010 01:41 PM
Discussion Calculator for pinion, head-speed, motor skyzoid Beginner Training Area (Heli-Electric) 8 Sep 18, 2009 10:31 PM
Discussion Boat set up calculator rcairboater Racing Boats - Electric 7 Sep 18, 2009 12:20 PM