Power available vs Power required ?

[SonOfGod]

Hello everyone,

I am new here, came here to meet some experts and solve my problems :)

I am working on a project, as performance and propulsion engineer of the team (undergraduate). I have done everything that is there to do, but now stuck, i just hit a brick wall that will make my first class degree a second/third class :(

I am calculating the power available or thrust available at range of altitude starting from sea level up to 20,000 feet. I know how much horsepower or power my engine supplies me at a given altitude. But that seems to be extremely huge figure compared to the amount i need.

Example:
AT 20,000 feet altitude
Engine power available = 2000 watts, power required = 200 watts
The propeller that I am using , is it the source of the problem ? Will it scale down the engine power by huge amounts when converting it to thrust ? How do i find it out ?

Any help will be appreciated a lot since my whole degree depends on this report :(

THANKS

 

[dtango]

Hmm, you're missing some info. What's the maximum level airspeed you want the plane to fly at altitude? Parasite drag increases with the square of velocity which means power required increases the faster you go. 2ndly if this is a prop aircraft propeller efficiency also varies with velocity topping out at about 80% typically meaning you get a max of about 80% of your engine power output at peak prop efficiency.