A new approach to calculating endurance in electric flight and comparing fuel cells and batteries

Contingency path planning for hybrid-electric UAS

“…The total propulsion efficiency through the generator (η pg ) is assumed to be invariable at 28.5% while the specific fuel The direct electric propulsion efficiency (η pe ) is assumed to be invariable at 50%. These values lie within range of experimental data found in [9], [14] and [15]. At the initiation of the cruise phase the aircraft is modelled to carry 5.5 liters of on board fuel, and to have a fully charged battery with a usable nominal capacity of 10 Ampere-hours at 44.4 Volt.…”

“…The adopted method in that study is an extension on the classical determination of battery-powered aircraft range, by including the Peukert effect on the battery capacity. This allows for a more accurate determination of the aircraft's battery range [9] [10]. When assuming no wind and a parabolic drag polar, the maximum range (R bp , in kilometers) for battery-powered sUAS in level and unaccelerated flight, without the influence of wind, is expressed by:…”

Mission performance trade-offs of battery-powered sUAS

“…Due to a lack of data the Peukert-constant n of the battery is therefore assumed to have a value of 1.05, corresponding to the typical value for a lithiumpolymer battery pack found in [3]. This observation corresponds to a 2012 study by Omar [16] where it was found that the Peukert-constant for Lithiumion based batteries typically vary between 1 and 1.09.…”

“…By considering the total battery capacity to be invariant, and instead modelling the effective power consumption to be increased, the range and endurance can be determined by solving Eq. 10 for different airspeeds [2] [3]. Consequently, the aircraft's maximum endurance (E max , in hours) and maximum range (R max , in kilometers) can be determined through:…”

“…However, the proposed theoretical model (and limitations) are applicable to any electric sUAS in similar configuration. The theoretical framework of this article builds upon the work of Traub [2] and Donateo et al [3] who studied the effects of the Peukert-constant and battery discharge rate on the in-flight performance of sUAS. Currently the P31015 is a conceptual aircraft, with an aerodynamic model that was approximated through simulations using the AVL software package [4].…”