Multidisciplinary Optimization of a Turboelectric Tiltwing Urban Air Mobility Aircraft

Abstract

Urban air taxis, also known as urban air mobility (UAM) vehicles, are anticipated to be an area of significant market growth in the near future. These vehicles are typically vertical takeoff and landing (VTOL) designs which are capable of carrying 1 to 30 passengers in an intra-urban environment with flights of less than 50 nautical miles. Development of UAM vehicles and their integration into the airspace will be enabled by advancements in a number of areas including electrified propulsion systems, structures, acoustics, automation, and controls. However, the strong multidisciplinary interactions for these unique vehicles presents a significant new design challenge. This work describes the development of a multidisciplinary analysis and optimization environment which can be used to support the conceptual design of these UAM vehicles, using efficient gradient based optimization with analytic derivatives. The tools included in this multidisciplinary analysis model the aircraft trajectory, vehicle aerodynamics, structures, and electrified propulsion system. The multidisciplinary environment created in this research is unique in that all the physics tools are tightly integrated together, with the trajectory model directly calling the aerodynamics, structures, and propulsion models. This multidisciplinary analysis environment is then demonstrated in the design optimization of a turboelectric tiltwing UAM vehicle concept.

Preliminary Design of Hybrid-Electric Propulsion Systems for Emerging Urban Air Mobility Rotorcraft Architectures

“…This is achieved with a weight penalty of 25% increase in EW compared to the baseline tilt-rotor. Hendricks et al [9] presented a multidisciplinary approach for the optimization of UAM vehicle propulsion systems applied to a tilt-wing configuration.…”

“…The design space is constrained by the SOC of the battery at the beginning and the end of the mission, corresponding to 95% and 15% SOC, respectively [9]. The minimum SOC (SOC 𝑚𝑖𝑛 ) is selected to avoid severe reduction in battery life.…”

Assessment of Methods for Propeller Performance Calculation at High Incidence Angles

“…Other set of contributions can be found with the UAM and wind turbine design and operations communities, as they are also interested in similar problems.Simmons [13,14] conducted wind tunnel tests and used system identification techniques to model propellers at incidence for a subscale eletric vertical takeoff and landing (EVTOL) vehicle in the context of urban air mobility (UAM). Ning [15] presented a blade element momentum method formulation that is specially suited for gradient based optimization, whose initial version [16] was used by Moore and Ning [17] to evaluate the effect of distributed electric propulsion on traditional aircraft and by Hendricks et al [18] to design a Turboelectric Tiltwing UAM vehicle using multidisciplinary design and optimization (MDO), and by Ning and Petch [19] to design downwind land-based wind turbines.…”

Integration and Flight Test of a 7 kW Turboelectric Vertical Take-Off and Landing Unmanned Aircraft

“…There are a variety of engines that can be utilized for hybrid vehicles, but gas turbine engines generally offer a superior power-to-weight ratio for the aircraft scale typical of UAM systems. There has been research focused on modeling hybrid VTOL UAM systems [11]; however, there is a distinct lack of published work on fabrication and flight testing such systems to address practical issues for safety and effectiveness.…”