Hey BR715 this is an interesting topic and hopefully I can give you some good information.
First the difference between horsepower and thrust is that horsepower is work over time meaning that
HP is comprised of three elements, Force, distance and time. One horsepower equals 33,000lbs moved one foot in one minute or 33,000lb-ft of work in one minute.
Thrust on the other hand is just a force in one direction. A jet engines thrust is just how hard it can push forward under a given set of conditions. Now what you need to relate the two, horsepower and thrust is to put thrust in the context of doing useful work and thus you can convert thrust to horsepower. Here is an example:
A given 747 needs a total of 45,000lbs of thrust to cruise at 564 Mph or 49,632 Fpm. The work done in one minute is a force of 45,000lbs over 49,632 feet in one minute or 2,233,440,000 lb-ft per minute. We know that one horsepower equals 33,000 lb-ft of work per minute so simple division 2,233,440,000/33,000 gives us an even 67,680
HP for the equivalent horsepower to move a 747 at cruise.
Typically an aero engineer calculates the power to move an airplane through the air in units of force for a given set of conditions. Using the method above will convert that force to work and
HP. This will not however correlate to engine power required to turn a propeller to generate that thrust as has been said already. 2H4's nifty post tells you the how and why relative to propellers.
Hope that helps some
-widebodyphotog
