A preliminary sizing method for hybrid-electric aircraft including aero-propulsive interaction effects

The potential benefits of hybrid-electric propulsion (HEP) have led to an increased interest in this topic over the past decade. One promising advantage of HEP is the distribution of power along the airframe, which enables synergistic configurations with improved aerodynamic and propulsive efficiency. The purpose of this paper is to present a generic sizing method suitable for the first stages of the design process of hybrid-electric aircraft, taking into account the powertrain architecture and associated propulsion–airframe integration effects. To this end, the performance equations are modified to account for aero-propulsive interaction. A power-loading constraint-diagram is used for each component in the powertrain to provide a visual representation of the design space. The results of the power-loading diagrams are used in a HEP-compatible mission analysis and weight estimation to compute the wing area, powerplant size, and take-off weight. The resulting method is applicable to a wide range of electric and hybrid-electric aircraft configurations and can be used to estimate the optimal power-control profiles. For demonstration purposes, the method is applied a HEP concept featuring leading-edge distributed-propulsion (DP). Three powertrain architectures are compared, showing how the aero-propulsive effects are inlcuded in the model. The results confirm the method is sensitive to top-level HEP and DP design parameters, and indicate an increase in wing loading and power loading enabled by DP.Flight Performance and Propulsio

Conceptual Design Studies of Boosted Turbofan Configuration for short range

This paper describes the current activities at the German Aerospace Center (DLR) and an associated consortium related to conceptual design studies of an aircraft configuration with hybrid electric propulsion for a typical short range commercial transport mission. The work is implemented in the scope of the European Clean Sky 2 program in the project 'Advanced Engine and Aircraft Configurations' (ADEC) and 'Turbo electric Aircraft Design Environment' (TRADE). The configuration analyzed incorporates parallel hybrid architecture consisting of gas turbines, electric machines, and batteries that adds electric power to the fans of the engines. A conceptual aircraft sizing workflow built in the DLR's 'Remote Component Environment' (RCE) incorporating tools of DLR that are based on semi-empirical and low level physics based methods. The TRADE consortium developed a simulation and optimization design platform with analysis models of higher fidelity for an aircraft with hybrid electric propulsion architecture. An implementation of the TRADE simulation and optimization design platform into the DLR's RCE workflow by replacing the DLR models was carried out. The focus of this paper is on the quantitative evaluation of the 'Boosted Turbofan' configuration utilizing the resulting workflow. In order to understand the cooperation between the DLR and TRADE consortium, a brief overview of the activities is given. Then the multi-disciplinary overall aircraft sizing workflow for hybrid electric aircraft built in RCE is shown. Hereafter, the simulation and optimization models of the TRADE design platform are described. Subsequently, an overview of the aircraft configurations considered in the scope of this work is given. The design space studies of the 'Boosted Turbofan' configuration are presented. Finally, the deviations of the results between the workflows with and without the TRADE modules are discussed

Conceptual Design Studies of “Boosted Turbofan” Configuration for short range

This paper describes the current activities at the German Aerospace Center (DLR) and an associated consortium related to conceptual design studies of an aircraft configuration with hybrid electric propulsion for a typical short range commercial transport mission. The work is implemented in the scope of the European Clean Sky 2 program in the project “Advanced Engine and Aircraft Configurations” (ADEC) and “Turbo electric Aircraft Design Environment” (TRADE). The configuration analyzed incorporates parallel hybrid architecture consisting of gas turbines, electric machines, and batteries that adds electric power to the fans of the engines. A conceptual aircraft sizing workflow built in the DLR’s “Remote Component Environment” (RCE) incorporating tools of DLR that are based on semi-empirical and low level physics based methods. The TRADE consortium developed a simulation and optimization design platform with analysis models of higher fidelity for an aircraft with hybrid electric propulsion architecture. An implementation of the TRADE simulation and optimization design platform into the DLR’s RCE workflow by replacing the DLR models was carried out. The focus of this paper is on the quantitative evaluation of the “Boosted Turbofan” configuration utilizing the resulting workflow. In order to understand the cooperation between the DLR and TRADE consortium, a brief overview of the activities is given. Then the multi-disciplinary overall aircraft sizing workflow for hybrid electric aircraft built in RCE is shown. Hereafter, the simulation and optimization models of the TRADE design platform are described. Subsequently, an overview of the aircraft configuration considered in the scope of this work is given. The design space studies of the “Boosted Turbofan” configuration are presented. Finally, the deviations of the results between the workflows with and without the TRADE modules are discussed