Low-Noise Design of Medium-Range Aircraft for Energy Efficient Aviation

Promising low-noise aircraft architectures have been identified over the last few years at DLR. A set of DLR aircraft concepts was selected for further assessment in the context of sustainable and energy-efficient aviation and was established at the TU Braunschweig in 2019, the Cluster of Excellence for Sustainable and Energy-Efficient Aviation (SE2A). Specific Top-Level aircraft requirements were defined by the cluster and the selected DLR aircraft designs were improved with focus on aircraft noise, emissions, and contrail generation. The presented paper specifically addresses the reduction of aviation noise with focus on noise shielding and modifications to the flight performance. This article presents the state of the art of the simulation process at DLR and demonstrates that the novel aircraft concepts can reduce the noise impact by up to 50% in terms of sound exposure level isocontour area while reducing the fuel burn by 6%, respective to a conventional aircraft for the same mission. The study shows that a tube-wing architecture with a top-mounted, forward-swept wing and low fan pressure ratio propulsors installed above the fuselage at the wing junction can yield significant noise shielding at improved low-speed performance and reduce critical fuel burn and emissions.

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Photo detector IC for Blu-ray-Disc applications: a realization applying efficient design methodologies

Advances in Radio Science ◽

10.5194/ars-9-219-2011 ◽

2011 ◽

Vol 9 ◽

pp. 219-223

Author(s):

S. Lange ◽

T. Reich ◽

J. Nowak ◽

B. Dimov ◽

M. Meister ◽

...

Keyword(s):

High Speed ◽

Low Noise ◽

Noise Power ◽

The Novel ◽

Efficient Design ◽

Design Methodologies ◽

Low Power Dissipation ◽

Speed Performance ◽

Performance Results ◽

Novel Design

Abstract. A high-speed photo detector IC for application in Blu-ray/DVD/CD drives is presented. Bandwidths for the highest gain of 254 MHz and 221 MHz for 405 nm (Blu-ray) and 635 nm (DVD) wavelengths, respectively, were achieved by applying novel design methodologies. The combination of this outstanding speed performance with its low power dissipation of 192 mW at 5V supply and the low noise power of −72 dBm at 300 MHz makes it the best in literature reported optical transceiver IC for Blu-ray and Blu-ray/DVD/CD multi drives. Beside the excellent performance results, the usage of the novel design methodologies gave us an increased design efficiency with 25% compared to earlier similar design processes.

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Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

Applied Sciences ◽

10.3390/app11010028 ◽

2020 ◽

Vol 11 (1) ◽

pp. 28

Author(s):

Emmanuel O. Osigwe ◽

Arnold Gad-Briggs ◽

Theoklis Nikolaidis

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Pressure Ratio ◽

Low Noise ◽

Closed Cycle ◽

Propulsion Systems ◽

Component Design ◽

Readiness Level ◽

Aerial Vehicle ◽

Turbine Design

When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.

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The Energy-Efficient Processing of Fine Materials by the Micropyretic Synthesis Route

Journal of Nanomaterials ◽

10.1155/2012/727656 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

H. P. Li

Keyword(s):

Energy Efficient ◽

Processing Time ◽

Combustion Temperature ◽

Processing Parameters ◽

The Novel ◽

Diffusion Controlled ◽

Efficient Processing ◽

The One ◽

Processing Techniques ◽

Diffusion Controlled Reaction

Energy-efficient processing of TiB compound with nanowhiskers by micropyretic synthesis is investigated in this paper. Micropyretic synthesis not only offers shorter processing time but also excludes the requirement for high-temperature sintering and it is considered as the one of the novel energy-saving processing techniques. Experimental study and numerical simulation are both carried out to investigate the correlation of the processing parameters on the microstructures of the micropyretically synthesized products. The diffusion-controlled reaction mechanism is proposed in this study. It is noted that nanosize TiB whiskers only occurred when the combustion temperature is lower than the melting point of TiB but higher than the extinguished temperature. The results generated in the numerical calculation can be used as a helpful reference to select the proper route of processing nanosize materials. The Arrhenius-type plot of size and temperature is used to calculate the activation energy of TiB reaction. In addition to verifying the accuracy of the experimental measures, the reaction temperature for producing the micropyretically synthesized products with nanofeatures can be predicted.

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Energy-efficient low-noise 16-channel analog-front-end circuit for bio-potential acquisition

Technical Papers of 2014 International Symposium on VLSI Design, Automation and Test ◽

10.1109/vlsi-dat.2014.6834893 ◽

2014 ◽

Cited By ~ 2

Author(s):

Shang-Lin Wu ◽

Po-Tsang Huang ◽

Teng-Chieh Huang ◽

Kuan-Neng Chen ◽

Jin-Chern Chiou ◽

...

Keyword(s):

Energy Efficient ◽

Low Noise ◽

Front End ◽

Analog Front End

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Ultra High Bypass Ratio Engine Sizing and Cycle Selection Study for a Subsonic Commercial Aircraft in the N+2 Timeframe

Volume 1: Aircraft Engine; Ceramics; Coal, Biomass and Alternative Fuels; Wind Turbine Technology ◽

10.1115/gt2011-45370 ◽

2011 ◽

Cited By ~ 18

Author(s):

Brian K. Kestner ◽

Jeff S. Schutte ◽

Jonathan C. Gladin ◽

Dimitri N. Mavris

Keyword(s):

Pressure Ratio ◽

Important Variable ◽

Direct Drive ◽

Commercial Aircraft ◽

Low Pressure Turbine ◽

Fuel Burn ◽

Technology Transition ◽

Fundamental Research ◽

Bypass Ratio ◽

Engine Cycle

This paper presents an engine sizing and cycle selection study of ultra high bypass ratio engines applied to a subsonic commercial aircraft in the N+2 (2020) timeframe. NASA has created the Environmentally Responsible Aviation (ERA) project to serve as a technology transition bridge between fundamental research (TRL 1–4) and potential users (TRL 7). Specifically, ERA is focused on subsonic transport technologies that could reach TRL 6 by 2020 and are capable of integration into an advanced vehicle concept that simultaneously meets the ERA project metrics for noise, emissions, and fuel burn. An important variable in exploring the trade space is the selection of the optimal engine cycle for use on the advanced aircraft. In this paper, two specific ultra high bypass engine cycle options will be explored: advanced direct drive and geared turbofan. The advanced direct drive turbofan is an improved version of conventional turbofans. In terms of both bypass ratio and overall pressure ratio, the advanced direct turbofan benefits from improvements in aerodynamic design of its components, as well as material stress and temperature properties. By putting a gear between the fan and the low pressure turbine, a geared turbo fan allows both components to operate at optimal speeds, thus further improving overall cycle efficiency relative to a conventional turbofan. In this study, sensitivity of cycle design with level of technology will be explored, in terms of both cycle parameters (such as specific thrust consumption (TSFC) and bypass ratio) and aircraft mission parameters (such as fuel burn and noise). To demonstrate this sensitivity, engines will be sized for optimal performance on a 300 passenger class aircraft for a 2010 level technology tube and wing airframe, a N+2 level technology tube and wing air-frame, and finally on a N+2 level technology blended wing body airframe with and without boundary layer ingestion (BLI) engines.

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Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

Revista de Saúde Pública ◽

10.1590/s1518-8787.2016050006431 ◽

2016 ◽

Vol 50 (0) ◽

Author(s):

Fabio Scatolini ◽

Cláudio Jorge Pinto Alves

Keyword(s):

Traffic Control ◽

Background Noise ◽

Noise Analysis ◽

Exposure Level ◽

Noise Levels ◽

Sound Exposure ◽

Operational Characteristics ◽

Data Compilation ◽

Noise Measurements ◽

Noise Data

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures.

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Understanding Screaming Channels: From a Detailed Analysis to Improved Attacks

IACR Transactions on Cryptographic Hardware and Embedded Systems ◽

10.46586/tches.v2020.i3.358-401 ◽

2020 ◽

pp. 358-401

Author(s):

Giovanni Camurati ◽

Aurélien Francillon ◽

François-Xavier Standaert

Keyword(s):

Spatial Diversity ◽

Low Noise ◽

Security Evaluation ◽

The Novel ◽

Proof Of Concept ◽

Wireless Devices ◽

Side Channels ◽

Security Evaluations ◽

The One

Recently, some wireless devices have been found vulnerable to a novel class of side-channel attacks, called Screaming Channels. These leaks might appear if the sensitive leaks from the processor are unintentionally broadcast by a radio transmitter placed on the same chip. Previous work focuses on identifying the root causes, and on mounting an attack at a distance considerably larger than the one achievable with conventional electromagnetic side channels, which was demonstrated in the low-noise environment of an anechoic chamber. However, a detailed understanding of the leak, attacks that take full advantage of the novel vector, and security evaluations in more practical scenarios are still missing. In this paper, we conduct a thorough experimental analysis of the peculiar properties of Screaming Channels. For example, we learn about the coexistence of intended and unintended data, the role of distance and other parameters on the strength of the leak, the distortion of the leakmodel, and the portability of the profiles. With such insights, we build better attacks. We profile a device connected via cable with 10000·500 traces. Then, 5 months later, we attack a different instance at 15m in an office environment. We recover the AES-128 key with 5000·1000 traces and key enumeration up to 223. Leveraging spatial diversity, we mount some attacks in the presence of obstacles. As a first example of application to a real system, we show a proof-of-concept attack against the authentication method of Google Eddystone beacons. On the one side, this work lowers the bar for more realistic attacks, highlighting the importance of the novel attack vector. On the other side, it provides a broader security evaluation of the leaks, helping the defender and radio designers to evaluate risk, and the need of countermeasures.

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