Re-Numbers
Re = v * l * 70.000Geschwindigkeit v[m/s]
Profiltiefe l[m]
Example: v=10 m/s, l=20cm = 0.2m
==> Re = 140000
Ncrit Parameters
situation Ncrit ----------------- ----- sailplane 12-14 motorglider 11-13 clean wind tunnel 10-12 average wind tunnel 9 <= standard "e^9 method" dirty wind tunnel 4-8
Calculate Power for steady flight
Very, simple calculation for an estimate result.minimal_Sink_rate [m/s] * g [m/s^2] * mass [kg] = ideal_power [W] required_electric_power [W] = ideal_power [W] / drive_efficency (~0.9) / prop_eff (~0.6) Example: sink rate: 0.5m/s mass: 0.5kg g: 9.81 m/s ideal_power = 2.4525 W required_power = 4.54 W