Aerodynamics of V/STOL flight , Aerodynamics of V/STOL flight , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Aerodynamics of V/STOL flight

Aircraft noise prediction

Purpose – The purpose of this paper is to describe the pre‐design and sizing of a smart leading edge section which is developed in the project SADE (Smart High Lift Devices for Next Generation Wings), which is part of the seventh framework program of the EU.Design/methodology/approach – The development of morphing technologies in SADE concentrates on the leading and trailing edge high‐lift devices. At the leading edge a smart gap and step‐less droop nose device is developed. For the landing flap a smart trailing edge of the flap is in the focus of the research activities. The main path in SADE follows the development of the leading edge section and the subsequent wind tunnel testing of a five meter span full‐scale section with a chord length of three meters in the wind tunnel T‐101 at the Russian central aero‐hydrodynamic institute (TsAGI) in Moscow.Findings – The presented paper gives an overview over the desired performance and requirements of a smart leading edge device, its aerodynamic design for the ...

Design of a smart leading edge device for low speed wind tunnel tests in the european project sade

A seamless and gapless high lift device at the wing’s leading edge has the potential for reduction of airframe noise as well as for drag. A concept of a smart leading edge device was developed, which, due to systems solutions, delivers an alternative to the droop nose device as used for the A380. The main emphasis of this new device is to realize a structure/system solution for a smooth leading surface, which can be deflected into a typical high lift application. With respect to the fact that laminarity is the only technology which has the potential for step changes in drag reduction within a suitable timeframe, smart seamless and gapless high lift devices are a mandatory enabler for future wings of significantly increased aerodynamic efficiency

Design of a Smart Droop Nose as Leading Edge High Lift System for Transportation Aircrafts

In order to include aircraft noise as an additional constraint in aircraft design, the German Aerospace Center (DLR) is currently developing a prediction tool named PANAM (Parametric Aircraft Noise Analysis Module) to analyse aircraft noise radiation in the preliminary design stage. This necessitates a detailed noise analysis for each iteration in
the design process. As a result, minimal demand in computational time becomes a major requirement and rules out CPU intense Computational Aeroacoustic methods. Instead,
aircraft noise is estimated through semi-empirical source models. The implemented noise source models are parametric, meaning that the effects on noise of individual sources
can be monitored throughout a simulated flight operation. In addition to common noise evaluation methods, new approaches are implemented in PANAM. The variation of noise levels versus time can be captured and animated. This allows for real-time evaluation of the influence of aircraft operating conditions on noise radiation. Thereby, noise related effects can be identfied and analysed. The level time histories for selected locations as well as animated noise footprints can be generated.

Tool Development for Low-Noise Aircraft Design

Aircraft noise in the vicinity of airports and its impact to residents represents a problem that is growing according to the increasing air traffic density. Improved and completely new designed aircraft configurations are promising approaches. But they represent only long-term solutions, whereas the application of newly designed noise abatement flight procedures (NAPs) could be able to contribute to the reduction of noise immission in a near future.
The paper will describe the NAP design process and an evaluation of the results. It is based upon several studies performed in Germany during the last 6 years.
Starting from existing NAPs, new procedures were designed using performance calculations, fast time simulations, full flight simulator studies and flight tests. Assessments of noise reduction as well as assessments of safety, operational feasibility, pilot workload, passenger comfort and economic aspects were carried out.
The newly designed “Segmented Continuous Descent Approach” results in a reduction of the >50 dBA maximum noise level area of about 40% and was investigated in detail by full flight simulator research into pilot workload and flight tests including on ground noise measurements. Analysis of take-off procedures showed advantages and disadvantages of steep departure flight paths and full thrust use.

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Design and evaluation of short-term realizable new noise abatement flight procedures

Short and middle term solutions are necessary to address the problem of aircraft noise in the vicinity of airports Several approach procedures leading to noise abatement were designed based on performance calculations and fast time simulations Two of them, namely the Low-Drag-Low-Power (LDLP) as a reference and the Segmented Continuous Descent Approach (SCDA) with a glide path intercept from above were analyzed on Airbus A320 and A330 full flight simulators with 44 pilots, evaluating pilot workload Via flight tests two further procedures, a Continuous Descent with a late gear extension (LCDA) and an optimized LDLP procedure with a steep final segment (SLDLP), are investigated on an Airbus A319 aircraft Noise measurements on ground were performed at 25 locations inside the departure and approach areas The investigations indicate that consequent practice of flight procedures such as continuous-descent and steep-final-approaches provide adequate noise abatement

Evaluation of Simulator and Flight Tested Noise Abatement Approach Procedures

The paper describes the design process of noise abatement procedures (NAPs) for the landing approach of commercial aircrafts with respect to safety, economy, passenger comfort and pilot workload. The methods of this process vary from basic performance calculation up to flight tests. All steps are conducted to noise calculation or simulation using different software programs. Results from related projects will be shown.

/pdf/aircraft-flight-procedure-design-with-respect-to-noise-psk79k3v4p.pdf

Aircraft Flight Procedure Design with Respect to Noise Abatement as well as Economical and Pilot Workload Aspects

During different investigations the aircraft slats were identified as one of the major sources for airframe noise. This suggests that design modifications of the wing especially the slats could reduce aircraft noise. For this purpose different wing model configurations from a standard to a slatless wing were designed.
Within the German Aerospace Center (DLR) project LEISA these wing configurations will be investigated. The wind tunnel measured lift and drag coefficients can be integrated in the fast time flight simulation tool (NAPSim) developed by DLR. With this tool it is possible to simulate noise abatement flight procedures flown by generic airplanes. The tool has an interface to the DLR noise calculation software SIMUL to compute and compare the different noise impact produced by these configurations. Furthermore the simulation can calculate economical aspects like time and fuel consumption, which are used to evaluate the different configurations, because one constraint is to achieve nearly the same performance that results from a standard wing design. 
In this paper the calculation of flight paths and the flight mechanics of an airplane with different wings and thus resulting noise is described.

Aircraft noise determination of novel wing configurations

Im Rahmen des Forschungsverbundes „Leiser Verkehr“ wurde untersucht, inwieweit ein neues Anflugverfahren hinsichtlich der Flugsicherheit und der Akzeptanz durch die Piloten durchfuhrbar ist. Zu diesem Zweck wurden zwei Verfahren – ein Standardverfahren (LDLP) und ein unter Larmaspekten weiter verbessertes Verfahren (SCDA) – in zwei Full-Flight-Simulatoren (A320 und A330) verglichen. Die Fliegbarkeit wurde mit 40 Piloten bzgl. technischer, psychologischer und physiologischer Parameter untersucht. Jeweils zwei Piloten fuhrten in einer Nacht acht Landeanfluge von jeweils 13 min. Dauer auf den Flughafen Munchen durch. Jede Simulation begann bei 9000 Fus Hohe und endete mit der Landung. Abwechselnd (als „pilot flying“ bzw. als „pilot non-flying“) wurden zwei LDLP und 6 SCDA absolviert. Neben technischen Grosen (z.B. Flughohe, Sinkrate, Geschwindigkeit, Schub, Fahren der Landeklappen und des Fahrwerks) wurden psychologische (z.B. Ermudung, Arbeitsbelastung, Akzeptanz, Aufgabenerfullung) und physiologische Parameter (z.B. EKG, EEG, EOG, Blutdruck, Cortisol) kontinuierlich oder diskret erhoben. Ein Debriefing mit umfangreichen Fragebogen komplettierte jede Versuchsnacht. Die geflogenen Bahnverlaufe zeigten eine Dispersion von der Vorgabe, wenn ein Sinkflug eingeleitet werden sollte. Der SCDA fuhrte zu einer Larmreduktion zwischen 2 und 5 dB im L max -Bereich zwischen 50 und 70 dB, daruber und darunter ergaben sich Erhohungen im Vergleich zum LDLP. Die physiologischen Daten und die regelmasigen Befragungen wahrend der Simulationen ergaben keine relevanten Unterschiede, die auf die unterschiedlichen Anflugverfahren zuruckzufuhren waren. Auch die fliegerische Leistung wurde als gleich gut beurteilt. Dagegen differenzierten die Piloten im Debriefing zwischen den Verfahren, wobei das SCDA haufig als nicht so sicher und arbeitsintensiver bezeichnet wurde sowie die Akzeptanz geringer war. Das SCDA kann als grundsatzlich durchfuhrbar und fliegbar bewertet werden. Einschrankungen ergeben sich z.Z. aus den Randbedingungen der Untersuchung und den technischen Unzulanglichkeiten. Es wird empfohlen, weitere Untersuchungen unter realen Flugbedingungen durchzufuhren, und technische Verbesserungen und Erprobungen zur Pilotenunterstutzung zur weiteren Beurteilung des SCDA vorzunehmen.

Reinhard König

Papers

Design and evaluation of short-term realizable new noise abatement flight procedures

Evaluation of Simulator and Flight Tested Noise Abatement Approach Procedures

Aircraft Flight Procedure Design with Respect to Noise Abatement as well as Economical and Pilot Workload Aspects

Aircraft noise determination of novel wing configurations

Untersuchung der Fliegbarkeit von lärmoptimierten Anflugverfahren durch den Piloten