I am wondering where to start on a project I have taken on for work comparing gas v. electric power. I am going for long range aircraft and so far the best we can do is about 75 miles distance with two 10 Ah five cell batteries connected in parallel. This is not good enough and the plane is getting pretty heavy. The batteries are expensive for this amp rating at about $450 each. I can get a saito fg-14 for $400 and it consumes 8cc per minute (assuming WOT??). In one liter of gas that is 125 minutes of run time. 2 liters would defiantly fit in my plane giving a rough estimate of 250 min or 4.16 hours of flight time. At our nominal speed of 32 miles per hour that would give about 130 miles distance. My question is where do I start in modeling the increase of flight efficiency as fuel is consumed and weight is decreased? My first idea is to simulate the plane at MTOW then simulate it at close to empty fuel weight and estimate it from there. Any help in the right direction would be much appreciated.
Thanks