An Update on Sizing and Performance Analysis of a Hybrid Turboelectric Regional Jet for the NASA ULI Program

Abstract

Under the NASA University Leadership Initiative (ULI) program, a team of universities are collaborating on the advancement of technologies a hybrid turboelectric regional jet, with an intent to enter service in the 2030 timeframe. In the previous studies of the ULI program, the in-service benefits of the technologies under development were analyzed by integrating the technologies of interest to a 2030 regional jet with a hybrid turbo-electric distributed propulsion system. As the program has progressed, the projected performances for each technology and subsystem have been updated. This paper presents an update in the sizing and performance analysis of the regional jet with the hybrid turbo-electric distributed propulsion system, by integrating the updated values of the technologies and subsystems to the vehicle. The updates in this paper include the DC/AC conversion links, efficiency of generator and cabling losses, weight of the wires, the battery cooling through the environmental control system, motor and inverter cooling by the thermal management system, and the redundancy strategy of the propulsion system. The updates of the results from the integrated model include the overall efficiency of the propulsion system, mission fuel savings, mission energy flow distribution, and the optimal hybridization rate in climb and cruise. The overall fuel saving benefit for the target 600-nmi mission is 19.9% compared to the baseline aircraft.

A Systematic Methodology for Populating the Aircraft Thermal Management System Architecture Space

“…For TeDP configuration, the selected local cooling loads are cabin, avionics, hydraulics, fuel, oil, battery, generator and motor. One generated global TMS is found to be similar to the one in an existing study [17], where motor is cooled by oil loop, and battery is cooled by ECS parallel to the cabin. This generated global architecture is shown in Fig.…”

“…One generated TMS cools the motor by oil, and then the oil is cooled by fan case air, as shown in Fig. 23, which corresponds to the architecture shown in Perullo's work [17]. The other generated TMS cools the motor by oil, and then the oil is cooled firstly by fan case air and fuel, as presented in Fig.…”

“…The design specifications of the TeDP concepts are shown in Table 4, of which the model was constructed by the authors in the previous work [17] for the ULI program. This configuration has eight electric fans to produce the thrust.…”

“…Such heat load is significantly larger than the usual cooling requirement in a conventional aircraft. For example, the heat generation for a 78-pax TeDP aircraft (20 MW propulsive power) is at the level of 880 kW as shown by the University Leadership Initiative (ULI) program [17], while the common ECS load is only around 160 kW for a conventional 350-pax aircraft. SSBJ is a class of business jets that performs civil supersonic transportation.…”

Design and Analysis of the Thermal Management System of a Hybrid Turboelectric Regional Jet for the NASA ULI Program

“…A number of technologies and aircraft concepts have been proposed and studied to meet such goals, and the turboelectric aircraft is one of the concepts of interest. Under the NASA University Leadership Initiative (ULI) program, teams from The Ohio State University (OSU), Georgia Tech (GT), University of Wisconsin-Madison (UW), University of Maryland (UMD), and North Carolina A&T (NCA&T) are collaborating to demonstrate the concept of Hybrid Turboelectric Distributed Propulsion (HTeDP) with corresponding technologies for a 2030 regional jet, of which the previous work has been summarized in authors' previous paper [3] and the update is summarized in the accompanying paper this year [4].…”