DLR Magazin 167: Beflügelnde Aussichten

Zukünftige Luftfahrzeuge müssen möglichst klimafreundlich und leise sein – trotzdem sollte der Komfort während der Reise nicht auf der Strecke bleiben. Neue Kabinenkonzepte könnten diese Anforderungen erfüllen. Am DLR-Institut für Systemarchitekturen in der Luftfahrt in Hamburg-Finkenwerder untersucht ein Team von Industriedesignerinnen und -designern, wie Menschen in Zukunft unterwegs sein möchten, wie sich ihr Reiseverhalten aufgrund der Pandemie ändern könnte und welche Auswirkungen dies auf die Gestaltung von Flugzeugen hat. Das Team erarbeitet neue Konzepte für eine modulare Flugzeugkabine, die an die Bedürfnisse der Menschen angepasst ist, und bezieht dafür auch die Passagiere in den Designprozess mit ein

Simulative Bewertung von Personenbewegungen in der Flugzeugkabine unter Berücksichtigung einer pandemischen Lage

Es ist davon auszugehen, dass die Covid-19 Pandemie den Luftverkehr weiterhin noch nachhaltig beeinflussen wird. Die Anzahl der angebotenen Sitzkapazitäten ist seit Pandemiebeginn um 50% eingebrochen und die ICAO-Prognose zeigt, dass vorpandemische Kapazitäten auch dieses Jahr noch nicht wieder erreicht werden, sondern etwa 20% darunter liegen. Weiterhin ist die Wiederaufnahme der Flugverbindungen stark von pandemischen Restriktionen geprägt. Neben der Vorlage von Impfzertifikaten oder Genesenennachweisen ist das Tragen von Masken und das Einhalten von Abständen erforderlich beziehungsweise wird empfohlen. In der Flugzeugkabine selber ist allerdings nur das Tragen einer Maske notwendig, andere Maßnahmen zur Ansteckungsreduzierung wie das Einhalten von Abständen werden für die Passagiere in der Regel nicht angewendet. Mit der vorliegenden Arbeit wird der Einfluss unterschiedlicher Konzepte beim Boarding und Deplaning der Passagiere auf ein mögliches Ansteckungsrisiko simulativ untersucht und bewertet, mit dem Ziel, ein leistungsfähiges Boardingkonzept zur Reduktion von Risiko-Begegnungen zu entwickeln. Durch die Modellierung und Simulation von Personenbewegungen kann wirksam untersucht werden, wie leistungsfähig frühe, neuartige und auch unkonventionelle Designkonzepte bezüglich der Schnittstellenprozesse des Boarding und Deplaning sind. Im Rahmen der Weiterentwicklung der Kabinenmodellierung und der dortigen Personenbewegungen wurde ein Bemessungswerkzeug zur Bewertung des Ansteckungsrisikos beim Boarding und Deplaning für die Passagiere in eine bestehende Simulationsumgebung integriert. Zur Anwendung kommt dabei der Algorithmus zur Bestimmung von Risikobegegnungen aus der Kombination von zu geringem Abstand und Dauer der Abstandsunterschreitung wie in der Corona-Warn-App angewendet

POST-PANDEMIC FLIGHT: ESTABLISHING THE MISSION OF THE AIRCRAFT CABIN OF THE FUTURE FROM THE PASSENGER’S POINT OF VIEW

As this paper is written, the world has been struck with a global pandemic, difficult to contain and very easy to spread. The most effective countermeasure so far is social distancing, to ensure no aerosols are exchanged. This poses a vast challenge in small, enclosed spaces, like an aircraft cabin. Unfortunately, such a countermeasure has had a great impact on the airlines and their business all over the globe. As the pandemic is not subsiding and scientists are predicting that similar situations will emerge more often in the future, it is highly necessary to take a look at the current state of the air travel and what it will have to offer to the passengers of the future. In the scope of InDiCaD (Innovative Digital Cabin Design), an internal project at German Aerospace Center (DLR), research has been done on the impact of the Covid-19 on the willingness of the passengers to fly under the given circumstances. The results of the research are threefold; firstly, a scenario where Covid-19 has left no traces, then a scenario where the consequences are enormous and the last one where the passengers are still willing to travel, albeit with an extra set of demands concerning health. These scenarios were used as a base to form mission definition for the cabin of the future as well as the fictive persona’s, depicting the passengers of the future. Through a series of workshops, there requirements have been used as foundation for building the morphological chart, consisting of partial design solutions. In this paper, the method of gathering and analysing the data will be shown as well as the resulting mission definition. The forth flowing list of requirements for designing an innovative cabin from a passenger’s point of view, able to cope with these unpreceded circumstances, will also be presented. The results of the workshop series will be shown, as well as an example of possible design outcome. To wrap up, an outlook into the future work during the project will be depicted, including the in-depth research as well as conceptual design solutions for the posed challenges

Urban Mobility: Airtaxi Cabin from a Passengers Point of View

Within German Aerospace Center (DLR), a project called HorizonUAM was launched in July 2020. Its main goal is to develop and design an aerial vehicle which would support the infrastructure of the ever-growing cities. The vehicle will be designed for the four different scenarios: airport shuttle, intracity transport, intercity transport and suburban connection. This paper shows the research concerning the potential users of the vehicle including their requirements and shows a possible design solution for an airtaxi cabin. The process has followed the Design Thinking Method, ensuring a central role for the users. To determine whether there are potential passengers willing to use such a vehicle, in-depth research has been done. Data found in previously done research has been compared with results of the in-house research, consisting of a number of workshops with representatives of German population as well as results form questionnaires sent out to a different group of German population. Based on this data, different fictive personas are created, to aid in understanding of the user’s needs. In addition, trend analysis on how the urban mobility is developing, has also been executed. The state-of-the-art solutions available are analyzed and their strengths and weaknesses determined. The entire research has resulted in an extensive list of requirements for the design of the cabin. To address such a complex design challenge, a morphological chart has been created, systematically deconstructing the main function into subfunctions. This has been done by multiple workshops with a constant team. This paper will show how the different scenarios influence the cabin design and will establish whether it is possible to serve multiple scenarios with a single cabin, from a passenger’s point of view. In addition, it will demonstrate the level of acceptance among alleged passengers and their vision on how a cabin of such a vehicle should look like and what it should focus on. Furthermore, it will display how the results of previously committed research are translated into first ideas, sketched as well as 2D as 3D

Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets.

We report on recent experimental results deploying a continuous cryogenic hydrogen jet as a debris-free, renewable laser-driven source of pure proton beams generated at the 150 TW ultrashort pulse laser Draco. Efficient proton acceleration reaching cut-off energies of up to 20 MeV with particle numbers exceeding 109 particles per MeV per steradian is demonstrated, showing for the first time that the acceleration performance is comparable to solid foil targets with thicknesses in the micrometer range. Two different target geometries are presented and their proton beam deliverance characterized: cylindrical (∅ 5 μm) and planar (20 μm × 2 μm). In both cases typical Target Normal Sheath Acceleration emission patterns with exponential proton energy spectra are detected. Significantly higher proton numbers in laser-forward direction are observed when deploying the planar jet as compared to the cylindrical jet case. This is confirmed by two-dimensional Particle-in-Cell (2D3V PIC) simulations, which demonstrate that the planar jet proves favorable as its geometry leads to more optimized acceleration conditions

Non-instantaneous polarization dynamics in dielectric media

Third-order optical nonlinearities play a vital role for generation and characterization of some of the shortest optical pulses to date, for optical switching applications, and for spectroscopy. In many cases, nonlinear optical effects are used far off resonance, and then an instantaneous temporal response is expected. Here, we show for the first time resonant frequency-resolved optical gating measurements that indicate substantial nonlinear polarization relaxation times up to 6.5\,fs in dielectric media, i.e., significantly beyond the shortest pulses directly available from commercial lasers. These effects are among the fastest effects observed in ultrafast spectroscopy. Numerical solutions of the time-dependent Schr\"odinger equation are in excellent agreement with experimental observations. The simulations indicate that pulse generation and characterization in the ultraviolet may be severely affected by this previously unreported effect. Moreover, our approach opens an avenue for application of frequency-resolved optical gating as a highly selective spectroscopic probe in high-field physics

Non-instantaneous polarization dynamics in dielectric media

Third-order optical nonlinearities play a vital role for generation1,2 and characterization 3-5 of some of the shortest optical pulses to date, for optical switching applications6,7, and for spectroscopy8,9. In many cases, nonlinear optical effects are used far off resonance, and then an instantaneous temporal response is expected. Here, we show for the first time resonant frequency-resolved optical gating measurements1012 that indicate substantial nonlinear polarization relaxation times up to 6.5 fs in dielectric media, i.e., significantly beyond the shortest pulses directly available from commercial lasers. These effects are among the fastest effects observed in ultrafast spectroscopy. Numerical solutions of the time-dependent Schrödinger equation13,14 are in excellent agreement with experimental observations. The simulations indicate that pulse generation and characterization in the ultraviolet may be severely affected by this previously unreported effect. Moreover, our approach opens an avenue for application of frequency-resolved optical gating as a highly selective spectroscopic probe in high-field physics

Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets

We report on recent experimental results deploying a continuous cryogenic hydrogen jet as a debris-free, renewable laser-driven source of pure proton beams generated at the 150 TW ultrashort pulse laser Draco. Efficient proton acceleration reaching cut-off energies of up to 20 MeV with particle numbers exceeding 109 particles per MeV per steradian is demonstrated, showing for the first time that the acceleration performance is comparable to solid foil targets with thicknesses in the micrometer range. Two different target geometries are presented and their proton beam deliverance characterized: cylindrical (∅ 5 μm) and planar (20 μm × 2 μm). In both cases typical Target Normal Sheath Acceleration emission patterns with exponential proton energy spectra are detected. Significantly higher proton numbers in laser-forward direction are observed when deploying the planar jet as compared to the cylindrical jet case. This is confirmed by two-dimensional Particle-in-Cell (2D3V PIC) simulations, which demonstrate that the planar jet proves favorable as its geometry leads to more optimized acceleration conditions

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe