Acceleration

[Doug I]

Static thrust to horsepower is easy. It's zero. Doing a static thrust test on our 747 gives a result of 220,000 pounds, but the motion caused is zero (at least we HOPE it's zero) so hence the work done is zero and the hp is zero.

Let's look at the dynamic thrust. Our 747 is cruising at Mach 0.9 at 40,000 feet. To do this it requires ~55,100 pounds of thrust. Taking into account the mass and distance moved and hence the work done that 55,100 pounds equates to ~87,300hp. So from this 1 pound = 1.6hp

Now let's look at a supersonic aircraft. We're at Mach 1.8 at 55,000 feet and are requiring ~11,600 pounds of thrust. Taking into account the mass and distance moved and hence the work done that 11,600 pounds equates to ~36,600hp. So from this 1 pound = 3.1hp

Doug