Dreolin — Propulsion Calculations
Propulsion sizing summary derived from the eCalc propeller calculator output in Batteries, Motors, ESCs.xlsx for the EirSpace 1 configuration. Results cover two battery configurations for a twin-motor fixed-wing aircraft.
- Wingspan: 1340 mm
- Wing area: 30.418 dm^2
- Chord: 227 mm
- Reference mass input: 3000 g
Power system configuration
- Battery: LiPo 10000 mAh (30/45C)
- ESC: max 40 A, 50 g
- Motor: T-Motor F90-1300 (1300 KV), 47 g
- Propeller: APC Electric E 7 x 4, 2 blades
- Wiring: AWG10 (5.27 mm^2) for battery and motor extensions
Battery and flight time
| Metric |
4S1P |
4S2P |
| Load (C) |
3.13 |
1.58 |
| Voltage (V) |
14.59 |
14.69 |
| Energy (Wh) |
148.0 |
296.0 |
| Total capacity (mAh) |
10000 |
20000 |
| Used capacity (mAh) |
8500 |
17000 |
| Min flight time (min) |
16.3 |
32.2 |
| Mixed flight time (min) |
24.5 |
39.7 |
| Battery weight (g) |
1004 |
2008 |
| Metric |
4S1P |
4S2P |
| Current (A) |
15.65 |
15.85 |
| Voltage (V) |
14.49 |
14.60 |
| RPM |
16551 |
16660 |
| Electric power (W) |
226.8 |
231.3 |
| Mechanical power (W) |
188.6 |
192.4 |
| Efficiency (%) |
83.2 |
83.2 |
| Estimated motor temp (C) |
50 |
51 |
| Metric |
4S1P |
4S2P |
| Static thrust (g) |
1011 |
1025 |
| Thrust at 60 km/h (g) |
666 |
677 |
| Pitch speed (km/h) |
101 |
102 |
| Specific thrust (g/W) |
4.46 |
4.43 |
Total drive metrics
| Metric |
4S1P |
4S2P |
| Drive weight (g) |
1318 |
2422 |
| Power-weight (W/kg) |
207 |
145 |
| Thrust-weight (ratio) |
0.91 |
0.63 |
| Current at max (A) |
31.29 |
31.69 |
| P(in) at max (W) |
463.1 |
469.1 |
| P(out) at max (W) |
377.3 |
384.8 |
| Efficiency at max (%) |
81.5 |
82.0 |
| Metric |
4S1P |
4S2P |
| Motors |
2 |
2 |
| All-up weight (g) |
2234 |
3238 |
| Wing load (g/dm^2) |
73.4 |
106.5 |
| Cubic wing load |
13.3 |
19.3 |
| Estimated stall speed (km/h) |
41 |
49 |
| Estimated level speed (km/h) |
91 |
92 |
| Estimated rate of climb (m/s) |
8.2 |
6.7 |
Notes
- eCalc reports an accuracy of +/-15% for these estimates.
- Both configurations use the same propeller and motor; differences are driven by battery capacity and mass.