Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

Abstract

The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft. Nomenclature

Aero-Propulsive Efficiency Requirements for Turboelectric Transport Aircraft

“…While the aerodynamic benefits of novel propulsion-system layouts such as leading-edge distributed propulsion [32], over-the-wing propulsion [33], under-the-wing propulsion [13], boundary-layer ingestion [34], or tip-mounted propulsion [35] have been studied at subsystem level, it is still unclear which of these configurations leads to the greatest benefit at aircraft level. Although such propulsion systems do not necessarily need a hybrid-electric powertrain [36], many radical aircraft configurations with improved propulsion-airframe integration are only viable when combined with HEP, and thus the overall benefit is highly dependent on the maturity of the powertrain components [37].…”

A Review of Concepts, Benefits, and Challenges for Future Electrical Propulsion-Based Aircraft

“…Given a significant reliance on gas turbine technology, these configurations are deemed to be viable with modest beyond state of the art advancement in electrical component technology [18]. Moreover, it is established that successful application of the aircraft based on turboelectric/partially turboelectric configurations has a high reliance on superiority of the electrical drivetrain components' technologies [19][20][21].…”

“…Understanding of the key performance parameters (KPPs) are essential in order to define the parameters necessary for operation and understand the likelihood of technology infusion. Jansen et al [20] identified specific two KPPs in the electrical drivetrain system for a turboelectric configuration: specific power, SP ED and efficiency, η ED . The study performed a break-even analysis with a modified Breguet range equation to identify the minimum allowable value that can preserve the operational empty weight, range, and the energy of the original aircraft.…”

Superconducting AC Homopolar Machines for High-Speed Applications

“…The key objectives are achieving compact and lightweight devices of the highest possible torque/weight and electrical efficiencies [7]. One typical application powers electric aircraft propulsion fans with energy generated from on-board generators directly coupled to high-speed gas turbines [8]. A second application is machines which act as both motor and generator integrated with high-speed flywheels for energy storage [9].…”