It's your lucky (or unlucky) day, because I happen to be bored.
Glad I could be helpful. The thing is, the drag on the aircraft is what will tell you how much thrust is required, because for level, unaccelerated flight, the thrust will equal the drag. I don't know how to get the actual thrust from N1 or N2
or EPR or any of that. I'll try to make a decent estimate of the drag here though, just so you can see how it works (these are the basic engineering equations, so they will be good estimates, but not exact).
So there's what's called the parasite drag coefficient for the aircraft, which basically accounts for the friction drag due to the air, and this coefficient basically comes with the aircraft - that is, it depends on the exterior of the plane. So let's assume that the parasite drag coefficient (Cd) is 0.03. This is a dimensionless number, but we'll get the drag from it. I'll also assume the airplane was at a weight of 120,000 lbs. The total drag will be the sum of the parasite drag and induced drag (drag due to lift).
Now, lift and drag coefficients have the same form, which is:
Cd = Drag/(0.5*wingarea*density*velocity^2)
Cl = Lift/(0.5*wingarea*density*velocity^2)
where Lift = Weight
Cl = 120,000/(0.5*wingarea*density*velocity^2) = 0.59
Induced drag coefficient(Cdi) = Cl/(pi*efficiencyfactor*aspectratio)
pi = 3.1415...,
I will assume the efficiency factor is 0.85, though I don't know how good this is,
and the aspect ratio = wingspan^2/wingarea
So...Cdi = 0.59/(3.1415*0.85*10.22) = 0.022
To get the total drag coefficient, add the parasite and induced drag coefficients.
Cdtotal = 0.03+0.022 = 0.052
Total drag(D) = Cdtotal*0.5*wingarea*density*velocity^2
D = 0.052*0.5*1344*(1.7556*10^-3)*416.67^2 = 10,651 lb.
This will be your thrust required, as thrust required equals drag.
= 10,651*416.67 = 4,437,873 lb*ft/s
which equals 8068.9 hp. Wow...I was actually pretty close in my previous post! Didn't expect that.
If you made it through, congrats. I tried to be as clear as I could, but having not gone over this stuff in a long while, it took some time. Comments/corrections welcome.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".