OK, I am following a set of plans for a build but now I am just pondering aircraft design and am trying to understand some things. More or less I am using this forum to think out load and see if anyone can offer their advice as well.
What started this thought was, "How much horsepower does a plane need to fly?" The catch is that I don't have a weight yet, guess I'll say 3000lbs. Goggle says 1hp=500lbs moved 1ft in 1 second which is .68mph. How in the world would I convert that into usable information to appropriately size an engine, or engines, to carry a...3000lb airframe? If 1hp moves 500lbs at .68mph then a 60hp motor would only move that same 500lbs at just over 40mph, correct?
Lets say I have a wingspan of 52' with a width of 6.75' wdith (straight leading and trailing edges) which gives me an area of 351ftsq and a wingload of 8.55lb per ftsq, at 3000lbs. At what speed does this thing fly? Taking my 500lb math from above and doing simple conversions I would need 360hp just to get this thing moving 40mph and that's not including lift and drag. Airfoil shape would be a flat bottom (what I consider standard for subsonic, general aviation aircraft) and an angle of attack of about 14 degrees.
I guess one problem is I don't know how to determine the Coefficient of lift to then use in the equation L=CL*p v2/2*A. Using generic data I could establish a "ceiling" for my hypothetical aircraft at 15,000ft so my p would be 14.96 with cruising altitude no higher than 10,000. I would technically be generating more lift at the cruising altitude. I guess I don't know where to take it from here.
Once again this is just for fun and learning.
What started this thought was, "How much horsepower does a plane need to fly?" The catch is that I don't have a weight yet, guess I'll say 3000lbs. Goggle says 1hp=500lbs moved 1ft in 1 second which is .68mph. How in the world would I convert that into usable information to appropriately size an engine, or engines, to carry a...3000lb airframe? If 1hp moves 500lbs at .68mph then a 60hp motor would only move that same 500lbs at just over 40mph, correct?
Lets say I have a wingspan of 52' with a width of 6.75' wdith (straight leading and trailing edges) which gives me an area of 351ftsq and a wingload of 8.55lb per ftsq, at 3000lbs. At what speed does this thing fly? Taking my 500lb math from above and doing simple conversions I would need 360hp just to get this thing moving 40mph and that's not including lift and drag. Airfoil shape would be a flat bottom (what I consider standard for subsonic, general aviation aircraft) and an angle of attack of about 14 degrees.
I guess one problem is I don't know how to determine the Coefficient of lift to then use in the equation L=CL*p v2/2*A. Using generic data I could establish a "ceiling" for my hypothetical aircraft at 15,000ft so my p would be 14.96 with cruising altitude no higher than 10,000. I would technically be generating more lift at the cruising altitude. I guess I don't know where to take it from here.
Once again this is just for fun and learning.
