Sir, do you know if there is a standard equation for a given speed/altitude/air density to figure the speed of heat where aircraft surface temperature changes from cold to hot? iirc it was about 500knots at a nominal altitude of 40,000'
thx
Posted on 09/14/2014 8:19:53 PM PDT by rey
How much of a jet engine’s thrust is needed to overcome drag.
Sir, do you know if there is a standard equation for a given speed/altitude/air density to figure the speed of heat where aircraft surface temperature changes from cold to hot? iirc it was about 500knots at a nominal altitude of 40,000'
thx
I like that. For a little variety, have her sometimes do a Conservation of Energy trace (don't worry, it just sounds tough, it's easy).
First recall that energy is the ability to do work.
Conservation of Energy: Energy cannot be created or destroyed, just transferred.
So here's an energy trace example. A plane taxing down a runway has kinetic energy (energy of motion). That energy has to come from somewhere, and go somewhere.
Where did the plane's kinetic energy come from? It came from gasoline in the plane's fuel tanks. Where did the gasoline's energy come from? From the ancient plants that formed oil. Where did those plants get that energy? From the sun. Where the sun got its energy is a religious question!
Now suppose the plane stops. Where did the plane's kinetic energy go? It has to go somewhere! The plane's energy was converted into heat by friction. The plane's tires get hot, and eventually the whole universe will get just a tiny bit warmer.
You can do such energy traces with a person walking, the energy stored in a hamburger, the energy stored in a brick at the top of a building, etc. I think it's quite fascinating.
If you have any questions about this, feel free to FRmail me. The first hundred questions will be free!
There is no cold. Only heat variance.
After that, I could not help you.
Can’t come up with a specific equation, but the effect of engine torque on controlling the aircraft — the Corsair had a lot of torque to overcome.
With the P-38, the effect of dual props turning in the same or different directions.
If you look around, you should be able to find some things that are at least interesting from a historical education perspective, but could give some math or physics education.
Check out Aerodynamics for Students. Looks like there's a fair amount of material that is suitable for algebraic understanding. I'm sure you'll have her in to DiffEq real soon!
true, cold by definition is simply the absence of heat, but if you touched the surface of a plane doing say 400K at 40000' it would feel cold, where the skin of a Blackbird reaches 1000+ i thought there might be a standard formula to determine the crossing point, thx
I wish I could help.
Very inspirational. Great post!
Lots of other math can be demonstrated with a flight computer, which is essentially a circular slide rule. The ASA A6B paper flight computers are CAD $13.95 and the metal version is $32.95 here.
interesting
From tire pressure and flattening try to estimate total weight and center of gravity. Estimate fuel tank capacities and cg locations. Work out trimming needs and fuel management.
much appreciated, thx again...
I think he crossed the wake turbulence of a leading aircraft in a turn Good thread bump.
This is a contradiction in terms, since "a plank with an angle of attack of about 55" is no other thing than an airfoil, however inefficient.
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