View Video Presentation: https://doi.org/10.2514/6.2021-3200.vid Urban Air Mobility (UAM) is increasingly becoming popular for Passenger or Cargo movement in dense smart cities. Several researches so far are focused on individual vehicle architectures such as multirotor or tiltrotor etc., but not much effort in a System of systems point of view where a homogenous fleet of vehicle with different passenger capacity, speed, and propulsive energy concepts are assessed in a framework for a successful UAM operations in a given city. An effort is made in this paper wherein, vehicle architecture is derived from the Concept of Operations (CONOPS) of scenarios such as urban and suburban operations and as well as propulsion subsystem for sustainable UAM. This paper approaches UAM aircraft design driven by System of Systems (SoS) approach and an agent-based simulation supports the vehicle architecture evaluation and fleet definition. The outcome of this study are: multiple aircraft design with subsystem architectures, ideal fleet size for the respective operational scenarios, autonomy and battery technology effectiveness on UAM throughput (to efficiently provide UAM on-demand service maximum passengers within 15 min wait time), and importantly, sustainability metrics such as total fleet energy required. Several System of Systems, system and subsystem level sensitivity research questions are addressed to understand the interlevel coupling.

Hybrid laminar flow control or HLFC design is a complex and multi-disciplinary process, which demands a thorough understanding of all aspects from a global systems viewpoint. The objective of the paper is to present a preliminary design of important components of an HLFC system that helps in quick assessment of conceptual system architectures. This is important to evaluate feasibility, system performance, and overall aircraft benefits at early stages of system development. This paper also discusses the various important system requirements and issues concerning the design of active HLFC systems, and the interfaces between various disciplines are presented. It can be emphasized from the study that the future compressor design for the HLFC system should consider the thermal management aspects and additional mass flow requirements from the aerodynamics-structure design optimization and also from water drain system solutions. A method to calculate the accumulated water content inside the plenum chambers is presented, and the effect of a drain hole on the power consumption is studied. A low order thermal management study of the HLFC compressor motor shows a high temperature rise in the windings for very high speed motors for long duration operation and calls for effective cooling solutions.

The work presented herein has been conducted within the DLR internal research project HorizonUAM, which encompasses research within numerous areas related to urban air mobility. One of the project goals was to develop a safe and certifiable onboard system concept. This paper aims to present the conceptual propulsion system architecture design for an all-electric battery-powered multirotor electric Vertical Takeoff and Landing (eVTOL) vehicle. Therefore, a conceptual design method was developed that provides a structured approach for designing the safe multirotor propulsion architecture. Based on the concept of operation the powertrain system was initially predefined, iteratively refined based on the safety assessment and validated through component sizing and simulations. The analysis was conducted within three system groups that were developed in parallel: the drivetrain, the energy supply and the thermal management system. The design process indicated that a pure quadcopter propulsion system can merely be designed reasonably for meeting the European Union Aviation Safety Agency (EASA) reliability specifications. By adding two push propellers and implementing numerous safety as well as passivation measures the reliability specifications defined by EASA could finally be fulfilled. The subsequent system simulations also verified that the system architecture is capable of meeting the requirements of the vehicle concept of operations. However, further work is required to extend the safety analysis to additional system components as the thermal management system or the battery management system and to reduce propulsion system weight.

This research addresses the increasing electrification of aircraft systems, driven by the need to improve energy efficiency and reduce CO₂ emissions in global aviation. The transition to more-electric aircraft (MEA) is advocated as a promising strategy, as it is expected to improve environmental performance and economic viability. However, this shift significantly increases the demand for on-board electrical power. One alternative to traditional engine generators is novel power supply systems such as fuel cell systems. In order to design these systems effectively, it is essential to determine the electrical power requirements that the fuel cells must supply. Estimating the electrical power consumption of individual aircraft systems is critical given the proprietary nature of manufacturer data. Using existing literature methods, this study aims to identify the essential variables for estimating the magnitude of power consumption. The research focuses on different aircraft models, taking into account their system architectures and electrification trends, in particular for Airbus and Boeing models. The study includes a detailed description of the aircraft systems, calculation methods, and presentation and analysis of the estimated electrical power requirements. Despite a lack of available data for comparison, the calculated results appear to be reasonably consistent with existing literature and provide valuable insights into the electrical power requirements of aircraft systems.

A key component in Hybrid Laminar Flow Control (HLFC) is a turbo-compressor, which requires an inverter. However, a harsh environment in combination with restrictive boundary conditions make the inverter design very challenging. Moreover, aviation certification standards have to be considered. By reason of its growing significance, a Model-Based Systems Engineering (MBSE) approach is described to break the HLFC system requirements down to the lower level of the inverter. Using the acquired set of requirements, the design of an inverter prototype was initiated. For this, the compressor motor, a Permanent Magnet Synchronous Motor (PMSM) running up to 150,000 $$\text {min}^{\text {-1}}$$min -1 at a power of more than 5 kW, was characterized by measurements. Thereafter, a control concept was elaborated and implemented on a preliminary electronics. In the end, feasibility tests were conducted on a testbed, whose results match well with the theory.

Designing an aircraft requires multidisciplinary analysis and data processing abilities, which are often spread over various partners. Effective collaboration across organisational boundaries is difficult, but essential. As the aerospace industry becomes increasingly digitalised, ever larger volumes of data and models must be exchanged. Heterogeneous tools, data formats, and infrastructures make it difficult to exchange data and to trace it. We propose using semantic graphs for data exchange to ensure interoperability, while semantic links between data models facilitate multidisciplinary and cross-organisational collaboration. Furthermore, our approach captures comprehensive metadata that describes the creation and modification of each dataset, thereby establishing a fully traceable data provenance chain. We demonstrate its functionality via a design process for an electromechanical actuator (EMA) given requirements from a different stakeholder (simulated). Having the requirements and the EMA models translated in Resource Description Framework (RDF) graphs, we are able to create links between them. This then enables the EMA model to be automatically re-evaluated when requirements change, ensuring that it complies with them. For the data exchange, we use the DLR SemanticHub, which utilises a graph database. By providing traceability of the data results provided in different data formats and the data origins, we enable transparency and accountability across organisational boundaries, which is important for trusted collaboration and compliance in intercorporational data exchange.