I'm trying to come up with some ballpark ranges for RC electric powered aircraft. The literature I find so far on range, like the Breguet range equation, seems focused on mass change from fuel consumption which is not the case in battery powered electric aircraft. So I thought I would start from scratch for my edification and invite sanity checks. McKay's reference, here, provided guidance. Below I've substituted terms convenient for my design.(adsbygoogle = window.adsbygoogle || []).push({});

Fundamentally, the maximum range is some optimal aircraft velocity x time aloft, and time aloft is the total energy carried divided by the rate at which it is used, i.e. power, corrected for the efficiency of the propulsion system:

R = Vwhere:_{opt}x (E_{batt}/P) x ε

R = maximum range

E_{batt}= energy capacity of the battery

ε = propulsion efficiency

P = power

and since force is power / velocity:

R = (Efor level flight:_{batt}/F_{thrust}) ε

F_{thrust}= Drag

Lift = mg

or

F_{thrust}= mg (D/L)

where:

m = aircraft mass

g = gravity

L/D = well known lift to drag ratio, or the glide ratio.

then

R = Ewhere:_{batt}x ε x (L/D) / mg

E_{batt}= C_{batt}x m_{e}

C_{batt}= battery specific energy

m_{e}= mass of battery

let

f_{batt}= fraction of aircraft mass dedicated to the battery

and

m_{e}= f_{batt}m

then

R = Cfinally:_{batt}x f_{batt}x m x ε x (L/D) / (mg)

R = ( C_{batt}/g ) x f_{batt}x ε x (L/D)

The term f_{batt}x ε x (L/D) is dimensionless. The fundamental range dependent on just carried energy is C/g.

Next up, some numbers.

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# Aerospace Max aircraft range - electric powered

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