Propulsion Scaling Methods in the Era of Electric Flight

摘要

An initial survey of commercial off-the-shelf motors, inverters and propellers was performed to determine torque vs weight, power vs. weight and thrust vs. weight, respectively. The data is from commercial sources and should be used with caution since the manufacturers are not required by law to provide accurate data. These authors feel this is a starting point for understanding which motors, inverters and propellers are best suited for eVTOL configurations, but further work will include proprietary test data, which will validate each manufactures claims. To highlight the value of this data, a quick study of motor weight for various 'types' of motors was done. Only the motor trends were used for this initial study; however, given power and thrust, we can determine the lowest weight inverter and propeller for initial aircraft sizing studies. An 8 rotor, one passenger and four passenger all electric eVTOL configuration (shown in Figure 1) was scaled using the methodology outlined in reference 2. These exemplary vehicles required a per-motor torque of 50 NM and 350 NM respectively. These torque values were then put into the weight equations found in section II from this paper to determine weight for various motor types. It can be observed from Figure 19 that for a given motor torque requirement, weight can be determined by motor type and used for aircraft design and sizing. This is just one example of how these trends can be used for optimization of weight for motors, inverters and propellers.