Development of cargo aircrafts with electric power plants

Аuthors

Karasev D. A.^*, Arutyunov A. G.^1**, Zagordan A. A.^2***

1. Volga-Dnepr airlines design center, 35, Usacheva, block 1, Moscow, 119048, Russia
2. Design Bureau «Volga-Dnepr» airlines, 14, Karbysheva str., Ulyanovsk, 432072, Russia

*e-mail: denis.karasev@volga-dnepr.com
**e-mail: artem.arutyunov@volga-dnepr.com
***e-mail: anatoliy.zagordan@volga-dnepr.com

Abstract

We have investigated the levels of specific batteries (AKB) characteristics, which assure both the technical and economic feasibility of a cargo aircraft with electric propulsion system development.

The calculation of the characteristics of electric cargo aircraft was based on the following assumptions:

• The relative weight of the airframe and aircraft systems excluding the engine and propulsion system’s weight, the level of flight aerodynamic quality, and the required take-off power-to-weight ratio, in the first approach, do not depend on the type of the power plant;

• The number of engines and the type of the main propulsion, of the fan of electric aircraft, are the same as of analogues with the traditional power plant.

The dependences of the aircraft takeoff weight from the specific energy density of the battery and the relative masses of the onboard battery for a number of payloads and ranges are shown in tables 1.2.

Table 1. The cost of charging the onboard battery to deliver 20 tons of cargo to a range of 5,500 km electric aircraft

The energy density of the onboard battery, kW·h/kg	4	4,5	5	5,5	6	6,5	7
Aircraft take-off weight ft, t	116,3	98,5	87,7	80,3	75,2	73	68,5
Energy consumed in flight, MW∙ h	131	111	97	90	84	80	77
The cost of energy consumed (at the price of $ 30/MWh), thousand USD	3,93	3,33	2,91	2,7	2,52	2,4	2,31
The cost of aircraft analogue refueling to perform the transport operation (if fuel costs $ 850/t, thousand $	17

Table 2. The cost of charging the onboard battery to deliver 100 tons of cargo to a range of 9000 miles electric aircraft

The energy density of the onboard battery, kW·h/kg	4	4,5	5	5,5	6	6,5	7
Aircraft take-off weight, t	724,6	543,5	454,6	400	365	339	319,5
Energy consumed in flight, MW∙ h	1186	888	743	653	598	555	523
The cost of energy consumed (at the price of $ 30/MWh), thousand USD	35,58	26,64	22,3	19,6	17,94	16,65	15,69
The cost of aircraft analogue refueling to perform this transport operations (if fuel costs $ 850/t, thousand $	85

The development of the mainline aircraft powered with electric power plant based on high-capacity batteries is technically feasible with the level of specific energy of on-board battery at about 4.5 — 5 kWh/kg (the maximum takeoff weight of the aircraft will exceed the takeoff weight of an analogue powered with conventional power plant by not more than 1.5 times, and aircraft performance will be identical). Upon achieving the energy density of on-board batteries over 6-6.5 kW·h/kg, the takeoff weight of the aircraft with electric propulsion system becomes lower than the takeoff weight of the aircraft fueled with hydrocarbon fuels.

Economic efficiency of applying the electric propulsion system in transport aviation primarily depends on the cost of the battery and its service life. By achieving cost-efficient service life utilization of ultra-battery at a level of 1.5-3 times lower than modern lithium-ion batteries demonstrate, the use of all-electric cargo aircraft will be economically feasible.

Keywords:

electric aircraft, cargo aircraft, battery, take-off mass, energy density, specific power

References

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