Temp Vs Mach no & Tas
Thread Starter
Join Date: May 2007
Location: In a tube
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Temp Vs Mach no & Tas
Can someone, help me with an easy way to remember what the relationship between TAS, Mach, and Temp is. For example; if you are cruising at a constant mach number and the temperature increases, what happens to the TAS - and vica verca.
Thanks in advance
Thanks in advance
Join Date: Jun 2004
Location: Australia
Posts: 1,843
Likes: 0
Received 0 Likes
on
0 Posts
Rainboe, Interesting linear formula for the normally expected temperature range, it seems reasonably accurate for day to day purposes
The exact formula, dirka, which is not linera, is -
TAS = 38.975 X SQR SAT X Mach Number,
Where, TAS is in Knots, and SAT (Static Air Temperature) is Degrees Absolute in Kelvin, i.e. °C + 273.15
The constant of 38.975 does suffer from a bit of Rounding Up/Down, depending upon the source of information, NASA's formulae work for me
If you look at both of the posts following your question, dirka, Hotter = Faster; Colder = Slower.
Regards,
Old Smokey
The exact formula, dirka, which is not linera, is -
TAS = 38.975 X SQR SAT X Mach Number,
Where, TAS is in Knots, and SAT (Static Air Temperature) is Degrees Absolute in Kelvin, i.e. °C + 273.15
The constant of 38.975 does suffer from a bit of Rounding Up/Down, depending upon the source of information, NASA's formulae work for me
If you look at both of the posts following your question, dirka, Hotter = Faster; Colder = Slower.
Regards,
Old Smokey
Join Date: May 2000
Location: australia
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
I've probably misread the last post, but for interest sake kelvin is not expressed as degrees kelvin, it is simply kelvin.
(ie water boils at 373 kelvin, not water boils at 373 degrees kelvin)
K
PS - and it is not spelt with a capital K
(ie water boils at 373 kelvin, not water boils at 373 degrees kelvin)
K
PS - and it is not spelt with a capital K