- #1
Bob584
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Hello everyone. Recently I have had a lingering need to (in a loose sense) conceptualize the aerodynamic resistance of an object traveling at high supersonic velocity. However it has been a long time and I am rusty on my physics. I am looking for a ballpark figure on the Newtons and Joules (1 hour of travel) required at velocity and do not have a specific physical aircraft design so I am neglecting skin friction, induced drag, wing properties etc...
So, cheating and using wiki...
https://en.wikipedia.org/wiki/Drag_(physics)
The power required to overcome the aerodynamic drag is given by:
the p value (100,000 feet = 0.0183 [p metric]) I got from this chart
https://user.engineering.uiowa.edu/~cfd/pdfs/tables/7-2B.pdf
For the theoretical values I set A (cross sectional area) to 7.0 square feet and the Coefficient of drag to 0.03. Velocity is 1020.86 m/s.
So plugging in the numbers I get... 2,044,273.27 N?
This is where I get confused, its always been a unit issue with me. I assume that the number above is in Newtons but when I try to figure out the energy required to keep up 1020.86m/s for 1 hour (3,675,096 m) W=FD I get this huge number of 7.51 x 10^12 J? of energy.
This doesn't seem right and its probably something simple I am missing that is compounding but I cannot see it; the energy given in my conclusion feels much too high.
Any help is greatly appreciated, thank you for your time.
So, cheating and using wiki...
https://en.wikipedia.org/wiki/Drag_(physics)
The power required to overcome the aerodynamic drag is given by:
the p value (100,000 feet = 0.0183 [p metric]) I got from this chart
https://user.engineering.uiowa.edu/~cfd/pdfs/tables/7-2B.pdf
For the theoretical values I set A (cross sectional area) to 7.0 square feet and the Coefficient of drag to 0.03. Velocity is 1020.86 m/s.
So plugging in the numbers I get... 2,044,273.27 N?
This is where I get confused, its always been a unit issue with me. I assume that the number above is in Newtons but when I try to figure out the energy required to keep up 1020.86m/s for 1 hour (3,675,096 m) W=FD I get this huge number of 7.51 x 10^12 J? of energy.
This doesn't seem right and its probably something simple I am missing that is compounding but I cannot see it; the energy given in my conclusion feels much too high.
Any help is greatly appreciated, thank you for your time.