CONTRIBUTIONS OF CABIN RELATED AND GROUND OPERATION TECHNOLOGIES TOWARDS FLIGHTPATH 2050

Abstract The vision of the European Commission (EC) for 2050 is a 75% reduction in carbon dioxide (CO2) emissions per passenger kilometer relative to the capabilities of conventional aircraft in 2000. This paper focuses on airframe related contributions to a reduction of CO2 emissions in terms of structural changes of the cabin and fuselage design. Furthermore, thus far disregarded emissions during the on-block time at the airport are considered and ground operation enhancements are presented to reduce these. For the methodical approach several separate sensitivity analyses were performed to assess the CO2 impact of cabin and fuselage modifications, in terms of higher passenger density, reduced interior weight or usage of Carbon Fiber Reinforced Plastic (CFRP) for the fuselage structure, on the basis of a narrow-body medium-to-short haul reference aircraft. Moreover, the impact of electric taxiing and reduced onblock Auxiliary Power Unit (APU) running time are investigated. The result of the investigated airframe related technologies is a 6.5% CO2 emission reduction compared to the reference aircraft and a 6.2% reduction for the ATM and ground operation. However, the reduction potential of the presented strategies is insufficient to reach to target Flightpath 2050 goals solely from the investigated areas. Hence, further studies have to be conducted to improve cabin related designs and ground operation based processes to ensure the fulfillment of the released targets

Comparison of Multi-Fidelity Rotor Analysis Tools for Transitional and Low Speed Flight Regimes

Urban and regional air mobility is a new mode of transportation currently attracting a lot of attention. Much effort is being put into preliminary design studies for various electric vertical takeoff and landing (eVTOL) concepts. Especially the aerodynamic modeling poses major challenges to both applications, the preliminary design and the control design of eVTOLs. One main factor affecting aerodynamic complexity is rotor aerodynamics and the respective couplings with other rotors, wings, and airframe. Thus, both applications share the need for a fast and user-friendly, yet sufficiently accurate analysis tool. This study provides an overview of four different rotor aerodynamic tools suitable for the preliminary and control design task of eVTOLs and a respective tool-selection for different applications. A cross-method comparison is performed for the tools DUST, FLOWLab, SARF and OpenVSP/VSPAero, with a focus on capturing complex rotor, rotor-rotor and rotor-wing aerodynamics. The Caradonna-Tung rotor, for which experimental data is available, represents the benchmark case. Subsequently, the Airbus A3 Vahana is used to extend the analysis to an aerodynamically complex eVTOL configuration for which a main wing rotor is analyzed. There, the rotor aerodynamics is analyzed in different flight phases, i.e., different phases of the transition. The comparison of the two cases shows possibilities and limitations with respect to the quality of the computational results and handling aspects of the respective tools. The results suggest that DUST provides accurate results and covers most relevant effects at the cost of higher computational complexity. Both, the FLOWLab tools as well as SARF provide sufficiently accurate results in a short time. Though, SARF does not cover friction drag and thus underestimates the rotor torque. OpenVSP often shows convergence issues, but otherwise shows comparable results to the previous two tools

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Vertiport Operations Modeling, Agent-Based Simulation and Parameter Value Specification

Urban air mobility (UAM) is the idea of creating a future mobility market through the introduction of a new mode of aerial transport with substantial travel time advantages. A key factor diminishing travel time savings is vertiport processes. So far, vertiport throughput capacity has only been studied in a static manner using analytical methods, which has been found to be insufficient. This paper wants to increase the level of understanding of operational dynamics on vertiport airfields by being the first to apply agent-based simulation. For this purpose, an existing vertiport model consisting of pads, gates and stands was refined through two means. First, a sensitivity study with over 100 simulations was executed shedding light on the driving processes on a vertiport airfield. Second, an expert interview series with 17 participants was conducted, letting the experts evaluate the model and specify relevant parameter values. Three main results should find mention here: (1) Pad operations were identified to be most impactful on passenger delays. (2) Pad and gate processes have a threshold capacity beyond which delays increase exponentially. (3) A refined vertiport model is presented, including the 27 most relevant parameters and their value specification. In conclusion, this paper finds that optimized vertiport airfield design is crucial to UAM operations, and dynamic passenger and vehicle interactions cannot be neglected

A Vertiport Design Heuristic to Ensure Efficient Ground Operations for Urban Air Mobility

Urban Air Mobility is a novel concept of transportation with unknown market potential. Even in conservative estimates, thousands of operations could be expected on a single vertiport. This exceeds known heliport operations, which is the most comparable existing mode of transport—by far. Vertiport operations, in particular the dynamics on the airfield, are not well understood; in the following article, we want to address this research gap. By using means of agent-based simulation, the following design drivers were identified: peaks in demand, imbalance between arrivals and departures, pad operations and gate operations. We calculate a practical hourly capacity of 264 movements for our baseline scenario consisting of 4 pads, 12 gates and 20 stand. We are further able to shown that avoiding this peak and staying below a maximum imbalance between arrivals and departures of less than 33 ensures an average passenger delay of less than 3 min. Lastly, we present a parameter study varying the number of pads and gates, the length of approach/departure and boarding/de-boarding and the level of demand. The results of this study are aggregated into a graphical design heuristic displaying the interchangeability of the mentioned aspects

A Mission Performance Evaluation Approach for Civil UAS Applications

The Unmanned Aircraft Systems (UAS) mission fulfilment grade is determined by performance capabilities of the system elements, such as UAV flight performance, sensor parameters, energy consumption and communication abilities. The mission simulation and evaluation tool chain developed at the Institute of Aircraft Design allows to assess the system effectiveness in terms of civil and commercial UAS applications and by this to evaluate trade off studies regarding the compatibility between the air vehicle, the sensor payload and the mission. The presented approach for mission performance evaluation is based on the calculation of an overall mission performance index implemented in the UAS design and optimization processes

A Mission Performance Evaluation Approach for Civil UAS Applications

The Unmanned Aircraft Systems (UAS) mission fulfilment grade is determined by performance capabilities of the system elements, such as UAV flight performance, sensor parameters, energy consumption and communication abilities. The mission simulation and evaluation tool chain developed at the Institute of Aircraft Design allows to assess the system effectiveness in terms of civil and commercial UAS applications and by this to evaluate trade off studies regarding the compatibility between the air vehicle, the sensor payload and the mission. The presented approach for mission performance evaluation is based on the calculation of an overall mission performance index implemented in the UAS design and optimization processes

Advanced Passenger Movement Model Depending On the Aircraft Cabin Geometry

The aircraft cabin and boarding procedures are steadily increasing focus points for both aircraft manufacturers and airlines, as they play a key part in the customer experience. In the German research project AVACON (AdVAnced Aircraft CONcepts), the boarding procedure is assessed using the PAXelerate boarding simulation. As the project demands an increased level of detail concerning the passenger movement model, this publication introduces an improved methodology. Additions to the model include the development of a method capable of describing the passenger walking speed in dependence of the surrounding objects, their proximity as well as the location of other passengers within the cabin. The validation of the model is performed using the AVACON research baseline and an Airbus A320. The model is then applied to an altered version of the Airbus A320 with an extended aisle and to a COVID-19 safe distance scenario. Regarding the results, an extended aisle width delivers boarding times reduced by up to 3%, whereas the COVID-19 assessment delivers a 67% increase in boarding times. Concluding, the integration of the newly developed model empowers PAXelerate to simulate a more detailed boarding process and enables a better understanding of the influence of cabin layout changes to an aircraft&rsquo;s boarding performance