% of max hp of each flight segment

[Lady Heath]

Dear all,
I need some help in estimating some figures for part of my final year project. In order to calculate the range I need to know the specific fuel consumption per flight segment i.e. taxiing, t/o, climb, cruise, descent and landing using the following eqn:

SFC = kg / hp*hr

I have all the info to carry this out per flight segment except the hp. I need to know the % of max hp per flight segment. For example am I correct in thinking that cruise = 75% max hp

I will be doing this for a 90hp engine and a 120 hp engine.

Any help would be much appreciated.

Thank you

[Dupre]

There is a wonderful piece of software called "X-Plane" which is a flight sim that lets you put to the screen in realtime things such as power output, fuel flow etc. It's easy enough to change the power output of the engines so you could choose a plane (perhaps the C-152) and fit the 2 different engines to it.

You could then test-fly the planes (in standardised conditions of course), noting down the power it’s producing at different stages of flight (I think you can output the data as a file, but i'm not sure how that works).

Anyway - that's the best I can come up with. I hope it’s of some use if you can’t find real data.

X-Plane can be found at <A HREF="http://www.x-plane.com" TARGET="_blank">www.x-plane.com</A> but you'll need a fairly beefy computer to run it (demo is free but quite big).

Out of interest, what is the project about - and what is it for? It sounds fascinating!

Feel free to send me an e-mail if there's anything I might be able to help with (rpm settings for a C-152 or if you can’t run x-plane for instance!)

Dupre.

[Horsepower]

Lady Heath,

I’d suggest you get your hands on a Pilot’s Operating Handbook for the aircraft you plan to use as a model: all the accurate figures you require can be extrapolated quite easily from this.

If you are planning to use the C152 (105HP, I think) as a model, I can dig out the Cessna POH from my training days and e-mail the appropriate graphs or post them here.

HP

[Lady Heath]

Thanks guys for your replies,

Dupre, my project is a design study and performance comparison of installing a diesel engines into light aircraft. There are 7 manufacturers at the moment. Wilksch airmotive have successfully test flown a Europa with 120hp diesel. Diesel engines have many advantages over piston engines. I know the range is increased but I need to know by what extent. My two case studies involve:

-The 120hp diesel engine compared to the 80hp Rotax912 installed in the europa

-the zoche diesel engine into the islander.

It is a really interesting project.