Aeropropulsive Interaction and Thermal System Integration within the ECO-150: A Turboelectric Distributed Propulsion Airliner with Conventional Electric Machines

Abstract

The ECO-150 is a 150 passenger Environmentally COnscious tube-and-wing regional airliner concept which is characterized by a turboelectric distributed propulsion (TeDP) system embedded within the inboard section of the wing. Since 2008, the ECO-150 concept has served to promote a more complete understanding of TeDP performance, integration, design requirements, and system complexities. Early versions of the ECO-150 claimed superconducting electronics cooled by onboard liquid hydrogen (LH 2 ); however, the infrastructure requirements of such a system are far out of reach for near-term technology. In this most recent investigation, the ECO-150R was equipped with conventional electric machines suitable for NASA's N+2 timeframe. A recirculating liquid thermal management system (TMS) with ram air heat exchangers was integrated into the design to support the electric machines. Additionally, three-dimensional CFD analysis of the aircraft guided a redesign of the inboard wing and validated prior lower-order estimates for aero-propulsive efficiency and high lift performance. Component integration exercises within the updated configuration illuminated unexpected yet solvable packaging challenges. Mission performance analysis showed the ECO-150R concept to be at least as efficient as a currently operating airliner despite systematically conservative assumptions for the mass and efficiency of the advanced technologies and several unclaimed opportunities for design optimization. Ultimately, the research discussed in this paper strengthened the credibility of the ECO-150 concept and confirmed the feasibility of TeDP systems with conventional electric machines. Nomenclatureaircraft total drag, lb f L = aircraft total lift, lb f M = Mach number T = aircraft total thrust, lb f TOFL = takeoff field length, ft TSFC = thrust specific fuel consumption, lb m /lb f /hr ∆T = difference in temperature, °R

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

“…The system level benefits and challenges of fully/partially turboelectric configurations were studied under NASA's N3-X [22][23][24], the single-aisle partially turboelectric aircraft with an aft boundary layer propulsor (STARC-ABL) design [25,26], Boeing's Subsonic Ultra Green Aircraft Research (SUGAR) Freeze design [27], and Empirical Systems Aerospace Inc. (ESAero)'s Environmentally Conscious 150 (ECO-150) design [28].…”

“…A large spectrum of aircraft designs has been conceptualized to this effect both on conventional and unconventional airframe designs. Ce-Liner utilizes a C-shape airframe [53], ECO-150 series designs are configured both for tube-and-wing and split-wing airframes s [28]. A blended wing body (BWB) airframe is considered in the N3-X design [23].…”

“…Furthermore, under a Small Business Innovation Research (SBIR) contract to ESAero, research investment was made to explore cryogenic and non-cryogenic technologies in the electrical power system [107]. The ECO-150, design assuming non-cryogenic SOA electrical technology, showed potential for 35% reduction in SFC, because of the benefits from a DEP [28].…”

“…ESAero developed design framework take-off gross weight (TOGW) suitable for studying the hybrid electric sizing and performance study. The tool can optimize a design with consideration from the coupled interaction between the thermal and propulsion system disciplines [28]. The framework has further grown, to be known as Propulsion Airframe Integration for Hybrid Electric Research (PANTHER).…”

NASA’s Magnetic Gearing Research for Electrified Aircraft Propulsion

“…System-level studies have been performed on a number of vehicle concepts that use EAP. These studies have shown the feasibility of achieving system-level benefits to energy consumption, fuel burn, and/or emissions [3][4][5][6][7][8][9].…”