T is thrust in Newtons P is power of motor in Watts η is propeller efficiency, 1 is perfect Η is motor efficiency, 1 is perfect d is propeller diameter in meters ρ is air density in kg/m³
Known numbers:
P = 350 W, or 175 W per rotor (a simplification, but close enough) d = 1.2 m ρ = 0.013 kg/m³ at Mars' surface
Using typical efficiencies for propellers and motors:
η = 0.75 Η = 0.9
Mass of helicopter in Mars' gravity is 0.68 kg.
Using these numbers for one rotor:
T = ³√(30625 ✕ 0.56 ✕ 0.81 ✕ 3.14 ✕ 0.72 ✕ 0.013) ≈ 7.4 N
7.4 N is around 0.75 kg of thrust for a single rotor - more than the helicopter's weight on Mars. So with both rotors it'll have more than enough thrust to fly there.
dominus_stercae 0 points 3 years ago
Can you provide some calculation supporting your assertion?
ETA: Here's a thrust calculation for this case.
Static propeller thrust T = ³√(P² ✕ η² ✕ Η² ✕ π ✕ (d²/2) ✕ ρ)
Where:
T is thrust in Newtons
P is power of motor in Watts
η is propeller efficiency, 1 is perfect
Η is motor efficiency, 1 is perfect
d is propeller diameter in meters
ρ is air density in kg/m³
Known numbers:
P = 350 W, or 175 W per rotor (a simplification, but close enough)
d = 1.2 m
ρ = 0.013 kg/m³ at Mars' surface
Using typical efficiencies for propellers and motors:
η = 0.75
Η = 0.9
Mass of helicopter in Mars' gravity is 0.68 kg.
Using these numbers for one rotor:
T = ³√(30625 ✕ 0.56 ✕ 0.81 ✕ 3.14 ✕ 0.72 ✕ 0.013) ≈ 7.4 N
7.4 N is around 0.75 kg of thrust for a single rotor - more than the helicopter's weight on Mars. So with both rotors it'll have more than enough thrust to fly there.