| Autor(en) | Bertsch, Lothar | Heinze, Wolfgang | Guérin, Sébastien | Lummer, Markus | Delfs, Jan Werner |
|---|---|
| Titel | 10 Years of Joint Research at DLR and TU Braunschweig toward Low-Noise Aircraft Design - What Did we Achieve? |
| Herausgeber | Aeronautics and Aerospace Open Access Journal |
| Erscheinungsjahr | 2019 |
| Abstract | This review article is based on an invited keynote presentation at the 22ndWorkshop of the Aero acoustics Specialists Committee of the CEAS. The event was held in September 2018 in Amsterdam with the main focus on the relation between aircraft design and noise impact. This article reviews the last years of joint research activities between the German Aerospace Center (DLR) and the Technical University of Braunschweig (TU BS) in the field of low-noise aircraft design. The joint research was initiated around 2008 between the DLR Institute of Aerodynamics and Flow Technology and the Institute of Aircraft Design and Lightweight Structures at TU BS. Around that time, DLR was developing a first version of an aircraft noise prediction tool. This tool has then consequently been implemented as a module into the aircraft design synthesis code of the TU BS. In 2012, for the first time, a fully automated and fully parametric aircraft design process with integrated noise prediction capabilities was established, i.e., including a full approach and departure flight simulation. The main focus lies on conventional tube-and-wing aircraft with turbofan or turboprop engine concepts. Ever since 2012, the tools have been under constant development and the simulation chain for low-noise aircraft design has been applied to various aircraft concepts. This article is comprised of a description of the tool development from 2008 until early 2018 and a selected application example. Some lessons learned and a brief outlook on future developments and applications conclude this review. |
| Autor(en) | Bertsch, Lothar | Wolters, Florian | Heinze, Wolfgang | Pott-Pollenske, Michael | Blinstrub, Jason |
|---|---|
| Titel | System Noise Assessment of a Tube-and-Wing Aircraft with Geared Turbofan Engines |
| Herausgeber | Journal of Aircraft. American Institute of Aeronautics and Astronautics (AIAA) |
| Erscheinungsjahr | 2019 |
| Abstract | A geared turbofan with an increased bypass ratio promises reduced engine noise generation if compared to conventional turbofan engines with lower bypass ratios. As a result, the dominance of other noise sources on an aircraft with geared turbofan engines is emphasized and will become more relevant. Consequently, to get an understanding of the modified noise source ranking due to the new engine concept, a noise assessment of the overall aircraft noise as received on the ground is essential: that is, a so-called system noise assessment. For this study a German Aerospace Center (DLR) and Technical University of Brunswick aircraft design synthesis process with integrated noise prediction capabilities is applied. The noise assessment is not limited to the overall vehicle noise as received on the ground but, moreover, the dominance and ranking of all individual noise sources are discussed. A direct comparison and evaluation of the flight performance and the system noise of the different vehicle variants under consideration are presented. Finally, the geared turbofan engine is also installed on an earlier low-noise aircraft concept featuring engine noise shielding. The influence of low-noise airframe measures in combination with a geared turbofan concept are promising, especially on an airframe architecture dedicated to engine noise shielding. |
| Autor(en) | Bertsch, Lothar | Wolters, Florian | Heinze, Wolfgang | Pott-Pollenske, Stephan-Michael | Blinstrub, Jason |
|---|---|
| Titel | Aeroacoustics research in Europe: The CEAS-ASC report on 2017 highlights, Contribution: System noise assessment of a tube-and-wing aircraft with geared turbofan engines |
| Herausgeber | Journal of Sound and Vibration |
| Erscheinungsjahr | 2019 |
| Abstract | Short review of DLR and TU Braunschweig application of a simulation process for aircraft design synthesis with integrated noise prediction capabilities. An existing process is upgraded in order to process external data from high-fidelity computation and measurements. Dedicated engine simulation data for a GTF engine and experimental findings for selected high-lift systems are incorporated into the study. Aircraft performance, e.g., direct operating costs, can now directly be compared to the predicted ground noise levels for different aircraft/engine combinations under consideration. The geared turbofan engine has been simulated on board of conventional tube-and-wing aircraft as well as on board of dedicated low-noise vehicles. It is demonstrated, that the combination of noise shielding and the geared turbofan concept is most effective. The most promising low-noise vehicle of the study is equipped with GTF engines that are shielded by the fuselage and the main wing. Consequently, the influence of the airframe noise sources is increased for this vehicle and any modification in order to reduce the airframe noise becomes especially effective. Application of low-noise airframe technologies to this vehicle reduce the overall aircraft noise as received on the ground. |
| Autor(en) | Schäffer, Beat | Bertsch, Lothar | Guerin, Sebastien |
|---|---|
| Titel | Aeroacoustics research in Europe: The CEAS-ASC report on 2017 highlights, Contribution: Uncertainty assessment of a parametric aircraft system noise prediction |
| Herausgeber | Journal of Sound and Vibration |
| Erscheinungsjahr | 2019 |
| Abstract | Short review of DLR and TU Empa reserach activities toward uncertainty assessment of aircraft noise predictions. A new approach to assess uncertainties associated with the predicted noise levels was introduced in previous publications. The overall uncertainty is thereby comprised of input data, noise modelling, and sound propagation uncertainties. Obviously, each modeled noise source is associated with different input data and modelling uncertainties. According to the constantly changing noise source ranking along typical flight procedures, the overall uncertainty of the predicted ground noise level is highly variable. The new approach is applied to a DLR simulation process to establish a quality assessment and enable a reliable system noise prediction. It is demonstrated how the prediction results are affected by the underlying and prevailing uncertainty. Noise isocontour areas are subject to significant variations when uncertainties are introduced. Uncertainty analysis reveals that uncertainty associated with input data and propagation effects can even exceed the uncertainties of the noise source models when simulating conventional vehicles. The established uncertainty assessment can readily by applied to conventional tube-and-wing vehicles with turbofan engines. |
| Autor(en) | Bertsch, Lothar | Schäffer, Beat | Guerin, Sebastien |
|---|---|
| Titel | Uncertainty Analysis for Parametric Aircraft System Noise Prediction |
| Herausgeber | AIAA Journal of Aircraft, DOI: 10.2514/1.C034809 |
| Erscheinungsjahr | 2018 |
| Abstract | Parametric noise assessment in the context of low-noise aircraft design and flight procedure optimization has been around for more than 15 years. Yet reliable and comprehensive uncertainty analysis of the overall aircraft noiseprediction process was not available for parametric tools in the past. This paper presents a methodology to assess the overall uncertainty of DLR, German Aerospace Center’s aircraft system noise simulation with the Software Parametric Aircraft Noise Analysis Module (i.e., definition of a general approach to specify uncertainties of the predicted ground noise immission). This allows discussion of the temporal and spatial distribution of the uncertainties. The noise-prediction uncertainties vary between locations along the flight path. The impact on exposure–response relationships due to the variation in uncertainty is discussed (i.e., the influence of varying noise source dominance along simulated flights). Results of this uncertainty assessment along typical flight procedures and their impact on the A-weighted maximum sound pressure level LAmax are presented. |
| Autor(en) | Bertsch, Lothar | Wolters, Florian | Heinze, Wolfgang | Pott-Pollenske, Michael | Blinstrub, Jason |
|---|---|
| Titel | System noise assessment of a tube-and-wing aircraft with geared turbofan engines |
| Herausgeber | AIAA SciTech Forum 2018 |
| Erscheinungsjahr | 2018 |
| Abstract | The Airbus A320neo family and the Bombardier CSeries can come equipped with a geared turbofan of increased bypass ratio. Such an engine concept promises reduced engine noise generation if compared to conventional turbofan engines with lower bypass ratios. As a result, the dominance of other noise sources on-board of an aircraft with geared turbofan engines are emphasized and will become more relevant. Consequently, to get an understanding of the modified noise source ranking due to the new engine concept, a noise assessment of the overall aircraft noise as received on the ground is essential, i.e., a so called system noise assessment. For this study a DLR & TU Braunschweig aircraft design synthesis process with integrated noise prediction capabilities is applied. An interface to process external input data allows the implementation of high-fidelity simulation results for the geared engine concept into the overall simulation process, i.e. including all required engine parameters for the noise prediction. The focus lies on the comparison of existing engine concepts and their impact on the overall vehicle design, flight performance, and ultimately the system noise. The noise assessment is not limited to the overall vehicle noise as received on the ground but moreover the dominance and ranking of all individual noise sources is discussed. A direct comparison and evaluation of the flight Performance and the system noise of the different vehicle variants under consideration is presented. Among the vehicle variants, one aircraft is adapted to better match the engine concept. A geared turbofan engine concept will come with an inherent and advantageous implication on the overall aircraft performance, i.e., reduced specific fuel consumption. Since such beneficial characteristics are identified in the Simulation results, the overall vehicle design is consequently adapted to fully exploit these characteristics. Furthermore, several known measures to reduce the airframe noise contribution are simulated on board of the vehicles under consideration. The system noise assessment will identify the impact of these technologies on the overall aircraft noise for each variant. Finally, the geared turbofan engine is also installed on board of an earlier low-noise aircraft concept featuring engine noise shielding. The impact of the new engine in combination with shielding effects is assessed. It is demonstrated that the influence of low-noise airframe measures in combination with geared turbofan aircraft concept are promising, especially on an airframe architecture dedicated to engine noise shielding. |
| Autor(en) | Blinstrub, Jason | Bertsch, Lothar | Heinze, Wolfgang |
|---|---|
| Titel | Assessment of the Noise Immission along Approach and Departure Flightpaths for Different SFB880 Vehicle Concepts |
| Herausgeber | AIAA AVIATION 2018, Atlanta, Georgia |
| Erscheinungsjahr | 2018 |
| Abstract | The number of flight movements is further increasing in the future and some major airports arealready at their capacity limit. Therefore, it becomes beneficial for short range aircraft tooperate on regional airports as well. Short range aircraft with conventional high-liftsystems, however, are not able to safely operate on the comparatively short runways ofregional airports. Instead, new aircraft concepts are required that are equipped with anactive high-lift system. Such an active high-lift system offers high lift coefficients and thusthe ability for short take-off and landing. In order to ensure a sustainable growth inaviation, such new aircraft concepts also have to offer reduced fuel consumption and lownoise on the ground. The Coordinated Research Center (SFB) 880 focuses on such an active high-lift system. This active high-lift system is comprised of a flexible leading edge device, referred to asDroop nose, and an internally blown flap at the trailing edge, referred to as Coanda flap. Within the SFB880, the active high-lift system is applied to several aircraft concepts. These aircraft concepts are equipped with different propulsion systems, that is, turbofanengines of different bypass ratio or a turbine-driven propeller engine. In this study, the noise prediction methodology for the noise assessment within theSFB880 is summarized and applied to the aircraft concepts. The assessment includes thenoise at the three noise certification points as well as along a line of observers. The studyalso includes a preliminary uncertainty assessment in order to evaluate the reliability ofthe predicted noise on the ground. The results show that the SFB vehicles can providesignificant noise reduction compared to a reference aircraft with a conventional high-liftsystem and turbofan engine. Most noise reduction can be achieved with the aircraft that isequipped with the ultra-high bypass ratio turbofan engine. |
| Autor(en) | Delfs, Jan | Bertsch, Lothar | Zellman, Christoph | Rossian, Lennart | Far, Ehsan Kian | Ring, Tobias | Langer, Sabine C. | Rossian, Lennart | Rossian, Lennart |
|---|---|
| Titel | Aircraft Noise Assessment - From Single Components to Large Scenarios |
| Herausgeber | Energies 2018, 11(2), 429, doi:10.3390/en11020429 |
| Erscheinungsjahr | 2018 |
| Abstract | The strategic European paper “Flightpath 2050” claims dramatic reductions of noise for aviation transport scenarios in 2050: “. . . The perceived noise emission of flying aircraft is reduced by 65%. These are relative to the capabilities of typical new aircraft in 2000. . . ”. There is a consensus among experts that these far reaching objectives cannot be accomplished by application of noise reduction technologies at the level of aircraft components only. Comparably drastic claims simultaneously expressed in Flightpath 2050 for carbon dioxide and NOX reduction underline the need for step changes in aircraft technologies and aircraft configurations. New aircraft concepts with entirely different propulsion concepts will emerge, including unconventional power supplies from renewable energy sources, ranging from electric over hybrid to synthetic fuels. Given this foreseen revolution in aircraft technology the question arises, how the noise impact of these new aircraft may be assessed. Within the present contribution, a multi-level, multi-fidelity approach is proposed which enables aircraft noise assessment. It is composed by coupling noise prediction methods at three different levels of detail. On the first level, high fidelity methods for predicting the aeroacoustic behavior of aircraft components (and installations) are required since in the early stages of the development of innovative noise reduction technology test data is not available. The results are transferred to the second level, where radiation patterns of entire conventional and future aircraft concepts are assembled and noise emissions for single aircraft are computed. In the third level, large scale scenarios with many aircraft are considered to accurately predict the noise exposure for receivers on the ground. It is shown that reasonable predictions of the ground noise exposure level may be obtained. Furthermore, even though simplifications and omissions are introduced, it is shown that the method is capable of transferring all relevant physical aspects through the levels. |
| Autor(en) | Giesecke, Daniel | Lehmler, Marcel | Friedrichs, Jens | Blinstrub, Jason | Bertsch, Lothar | Heinze, Wolfgang |
|---|---|
| Titel | Evaluation of ultra-high bypass ratio engines for an over-wing aircraft configuration |
| Herausgeber | Journal of the Global Power and Propulsion Society, 2, 493–515 |
| Erscheinungsjahr | 2018 |
| Abstract | Today, main hub airports are already at their capacity limit and hence, smaller airports have become more interesting for providing point-to-point connections. Unfortunately, the use of regional airports induces an increased environmental footprint for the population living around it. In an attempt to solve the related problems, the research project Coordinated Research Centre 880 aims to examine the fundamentals of a single-aisle aircraft with active high-lift configuration powered by two geared ultra-high bypass turbofan engines mounted over the wing. Low direct operating costs, noise shielding due to the over-wing configuration, and short runway lengths are the main advantages. Highlighting the performance, economical and noise benefits of a geared ultra-high bypass engine is the key aim of this paper. This assessment includes a correspondingly adjusted aircraft. Open literature values are applied to design the two investigated bypass ratios, a reference engine with a bypass ratio of 5 and 17 respectively. This study shows that a careful selection of engine mass flow, turbine entry temperature and overall pressure ratio determines the desirable bypass ratio. The aircraft direct operating costs drop by 5.7% when comparing the designed conventional with a future ultra-high bypass ratio engine. Furthermore, the sound at source for a selected mission and operating condition can be reduced by 7 dB. A variable bypass nozzle area for the ultra-high bypass ratio engine is analysed in terms of performance and operability. An increase of safety margin is shown for the turbofan engine with a variable bypass nozzle. It is concluded that this unconventional aircraft configuration with ultra-high bypass ratio engines mounted over the wing has the potential to relieve main hub airports and reduce the environmental impact. |
| Autor(en) | Rang, Joachim | Heinze, Wolfgang |
|---|---|
| Titel | An Optimal Configuration of an Aircraft with High Lift Configuration Using Surrogate Models and Optimisation Under Uncertainties |
| Herausgeber | Advances in Structural and Multidisciplinary Optimization, Springer International Publishing AG, 2018 |
| Erscheinungsjahr | 2018 |
| Abstract | Nowadays many simulations are computationally expensive, which is disadvantageous if one is interested in the quantification of uncertainties, parameter studies or in finding an optimal or robust design. Therefore often so-called surrogate models are designed, which are a good approximation of the original model but computationally less expensive. In this paper we first look for an approximation method to design a surrogate model for the simulation of a civil aircraft with active high lift configuration. Such aircrafts have the advantage that only small run-ways for take-off and landing are necessary. A first result, presented in this paper, is a configuration of the aircraft, where the direct operating costs (DOCs) are minimised. For the optimisation process seven parameters are chosen, for example the Mach number in the cruise flight and the area of the wing. In a second step we define 28 uncertain parameters and repeat the optimisation process including these uncertain parameters to derive a robust configuration. |
| Autor(en) | Blinstrub, Jason | Bertsch, Lothar |
|---|---|
| Titel | Towards an Impact-Based Noise Reduction Method for Conceptual Aircraft Design |
| Herausgeber | New Results in Numerical and Experimental Fluid Mechanics X. Notes on Numerical Fluid Mechanics and Multidisciplinary Design, vol 132. Springer, Cham |
| Erscheinungsjahr | 2017 |
| Abstract | Aircraft exterior noise is typically reduced by optimizing an isolated aircraft component. The noise emission of this component is optimized with high-fidelity tools or wind tunnel measurements. However, if installed on-board of the aircraft the optimization may not have the desired effect on the total noise impact due to propagation effects or the interaction with other components. Hence, a method is presented, that derives noise reduction requirements for aircraft components based on the total aircraft noise impact. The method is implemented in a parametric aircraft noise prediction tool and applied to a reference aircraft. The aim is to use the noise requirements within conceptual aircraft design to obtain low-noise aircraft in a target-oriented way. Ultimately, this may be a first step towards a noise-to-design process. |
| Autor(en) | Radespiel, Rolf | Heinze, Wolfgang | Bertsch, Lothar |
|---|---|
| Titel | High Lift Research for Future Transport Aircraft |
| Herausgeber | Deutscher Luft- und Raumfahrtkongress, München, 5.-7. September |
| Erscheinungsjahr | 2017 |
| Abstract | Careful analysis of long-term objectives of air transport indicates that the needed progress in vehicle performance cannot be achieved by following the current, evolutionary technology development. Particular examples are noise reduction and high-lift performance at take-off and landing. The long-term objectives call for research on the fundamentals for a new segment of commercial low-noise transport aircraft with short takeoff and landing capability, which allows a much better integration into the metropolitan areas of the industrialised society. Such research is in the focus of the Collaborative Research Centre CRC 880. The Centre aims at drastic reductions of airframe noise by developing the fundamentals of noise reducing surfaces in aeroacoustic and aerodynamic design. A promising approach towards reducing engine noise shields the noise by suited configuration design. Improving the efficiency of active high lift requires reducing the flow actuation power. For this objective the benefits of form-variable leading edges, by exploiting the synergies of suction and blowing in active high-lift flaps with spanwisely distributed compressor units, and finally the potentials of dynamic flow control are explored. The advances obtained in noise reductions and in effective high-lift technologies are assessed using fully iterated aircraft designs. The Centre also seeks new knowledge on the dynamic behaviour of aircraft with active high lift during flight in the atmospheric boundary layer. Therefore, the flight mechanics of critical landing manoeuvers is analysed along with exploring the fundamentals of unsteady flow around active high-lift wings and the aero-elastic reactions of the wing structure on flight loads. |
| Autor(en) | Blinstrub, Jason | Heinze, Wolfgang | Bertsch, Lothar | Simons, Dick | Snellen, Mirjam |
|---|---|
| Titel | SYSTEM NOISE ASSESSMENT OF AN AIRCRAFT WITH COANDA FLAPS |
| Herausgeber | Research & Education in Aircraft Design, 12.-14. Sep. 2016, Warschau, Polen |
| Erscheinungsjahr | 2016 |
| Abstract | An innovative aircraft design of the Collaborative Research Centre (SFB) 880 features a new active high-lift system. This high-lift system is comprised of a droop-nose leading edge device and a Coanda flap as the trailing edge device. It offers very high lift coefficients and thus the ability to operate at airports that have reduced runway lengths, such as regional airports. Consequently, the assessment of aircraft noise is of utmost importance. The overall system noise on the ground is predicted using a parametric aircraft noise prediction tool. Although a parametric noise source model for the Coanda flap does not exist, it is estimated with a conventional Fowler flap model to evaluate the qualitative noise reduction potentials. The new design is compared with a regular aircraft that is equipped with a conventional high-lift system. Both designs are tested on individually calculated continuous decent approaches. The results show that airframe noise of the new aircraft is decreased due to later flap deflection and reduced speed. The engine noise, however, is significantly increased, especially on the glide slope. Hence, it dominates the overall noise on the ground, eliminating the benefits of the airframe noise reduction in the proximity of the airport. It is shown that the noise reduction potentials can only be exploited if the approach trajectory is individually optimized for low-noise. |
| Autor(en) | Weiss, Tayson |
|---|---|
| Titel | Automated aerodynamic model generation in preliminary aircraft design |
| Herausgeber | Deutscher Luft- und Raumfahrtkongress, DLRK-Paper 2016-0072, Braunschweig, 13.-15. September |
| Erscheinungsjahr | 2016 |
| Abstract | A scheme for the automated generation of aerodynamic 3D-panel models within an integrated preliminary aircraft design framework is presented. The described approach covers a wide range of configurations and allows for an explicit geometric representation of deployed high lift and control surfaces. The featured high lift devices encompass passive and active plain flap, fowler flap, slat and contour variable droop nose. The produced panel grids encompass structured and unstructured domains. This report summarizes the model generation process, the underlying data architecture, as well as external software used. An example case demonstrates the applicability of the model generation scheme to a multidisciplinary aircraft design analysis. |
| Autor(en) | Bertsch, Lothar | Heinze, Wolfgang | Lummer, Markus |
|---|---|
| Titel | Application of an Aircraft Design-To-Noise Simulation Process |
| Herausgeber | AIAA AVIATION 2014, Atlanta, Georgia, USA |
| Erscheinungsjahr | 2014 |
| Abstract | System noise has been integrated as an additional design objective within conceptual aircraft design. The DLR system noise prediction tool PANAM accounts for individual noise sources depending on their geometry and operating conditions. PANAM is integrated into the existing aircraft design framework PrADO from the Technical University of Braunschweig in order to realize a design-to-noise simulation process. In addition, a ray-tracing tool from DLR, SHADOW, is incorporated into the simulation framework in order to account for structural engine noise shielding. The overall simulation process is then applied to identify promising low-noise aircraft concepts. The presented application aims at fan noise reduction through shielding. For the selected reference aircraft, the fan is a major noise source during both landing and takeoff. It is demonstrated, that the aircraft designers influence on the environmental vehicle characteristics is significant at the conceptual design phase. Usually, a trade-off between extensive engine noise shielding and economical flight performance is inevitable. The new design-to-noise process is well suitable to assess all four measures of ICAOs balanced approach. |
| Autor(en) | Krosche, Martin | Heinze, Wolfgang |
|---|---|
| Titel | A Robustness Analysis of a Preliminary Design of a CESTOL Aircraft |
| Herausgeber | Informatikbericht 2014-02, Institut für Wissenschaftliches Rechnen, Carl-Friedrich-Gauß-Fakultät, TU Braunschweig |
| Erscheinungsjahr | 2014 |
| Abstract | As part of the Collaborative Research Center 880 preliminary aircraft design activities are carried out for a new class of low-noise cruise-efficient transport aircrafts with short take-off and landing capabilities (CESTOL). A corresponding aircraft is quite different from a state-of-the-art commercial aircraft because of the use of active high-lift devices. The fact that new technologies are not sufficiently understood yet in combination with the assumption of common design data and the use of classical calculation methods expresses itself in uncertainties which are of epistemic character. The robustness of a deterministic CESTOL aircraft design towards parameters such as the necessary engine thrust, direct operating costs, or the runway lengths is investigated here concerning the mentioned uncertainties. For this purpose a stochastic description of parameter variations of the design is formulated. Stochastic quantities are computed by Monte Carlo (MC) sampling to rate the robustness. A distributed component-based software implementation is used to perform the MC sampling. The software system is installed on a Linux cluster with several multi-CPU computers, a deterministic sample is simulated through the design program PrADO. |
| Autor(en) | Müller, Lars | Heinze, Wolfgang | Kozulovic, Dragan | Hepperle, Martin | Radespiel, Rolf |
|---|---|
| Titel | Aerodynamic Installation Effects of an Over-the-Wing Propeller on a High-Lift Configuration |
| Herausgeber | J. Aircraft, Vol. 51, No. 1, pp. 249-258, 2014 |
| Erscheinungsjahr | 2014 |
| Abstract | Preliminary design studies indicate that a cruise-efficient short takeoff and landing aircraft has enhanced takeoff performance at competitive direct operating costs when using high-speed propellers in combination with internally blown flaps. The original tractor configuration is compared to an over-the-wing propeller, which allows for noise shielding. An additional geometry with partially embedded rotor similar to a channel wing is considered to increase the beneficial interaction. This paper shows the aerodynamic integration effects with a focus on climb performance and provides an assessment of the three aforementioned configurations for a simplified wing segment at takeoff conditions. Steady Reynolds-averaged Navier–Stokes simulations have been conducted using an actuator disk model and were evaluated based on the overall design. Interacting with the blown flap, the conventional tractor propeller induces large lift and drag increments due to the vectored sliptream. Although this effect is much smaller for an over-the-wing configuration, by halving the lift augmentation, the lift-to-drag ratio and the propulsive efficiency are considerably improved. Besides a moderate lift gain, the main advantage of a channel wing design is the location of the thrust vector close to the center of gravity resulting in a smaller nosedown pitching moment due to thrust. A disadvantage of over-the-wing propellers is the inhomogeneous inflow at higher velocity, which leads to oscillating blade loads and reduced efficiency. |
| Autor(en) | Radespiel, Rolf | Heinze, Wolfgang |
|---|---|
| Titel | SFB 880 - fundamentals of high-lift for future commercial aircraft |
| Herausgeber | CEAS Aeronautical Journal, DOI 10.1007/s13272-014-0103-6 |
| Erscheinungsjahr | 2014 |
| Abstract | The recently founded Collaborative Research Centre SFB 880 of the Technische Universität Braunschweig, „Fundamentals of High-Lift for Future Commercial Aircraft“, develops new knowledge in aircraft noise, in advanced approaches towards active high lift, and in the dynamics of flight with active high lift during short take-off and landing operations. The Research Centre has therefore devised a range of research projects that aim at integrated aeroacoustic and aerodynamic design capabilities for drastic noise reductions and at the generation of active high lift with an extremely high efficiency of the used onboard power. Flight dynamics of commercial aircraft with increased lift capabilities for take-off and landing due to active control means and including the effects of aeroelasticity and engine failure modes are also investigated. The Research Centre has developed a joint strategy for technology assessment using high-quality conceptual design data of a reference aircraft that represents the state of the art in CO2 reductions, low noise, and short take-off and landing for point-to-point air connections within Europe. The paper describes the overall strategy of the coordinated research work and gives examples of recent results. |
| Autor(en) | Weiss, Tayson |
|---|---|
| Titel | Powered High Lift Aerodynamics in Preliminary Aircraft Design |
| Herausgeber | 62. Deutscher Luft- und Raumffahrtkongress, Stuttgart, 2013 |
| Erscheinungsjahr | 2013 |
| Abstract | An appropriate mapping of jet momentum expenditure and lift gain is prerequisite to the preliminary design of powered high lift aircraft. Due to the complex nature of active high lift flows this mapping is usually found at high computational costs, detrimental to an aircraft design process characterized by a vast design space. This paper presents a procedure allowing for comparatively fast aerodynamic calculation of powered high lift aircraft designs utilizing the Coanda effect. The method relates a 3D potential theory based aerodynamic aircraft model to an airfoil data field obtained by a Reynolds-averaged Navier-Stokes code. The procedure is demonstrated for a high lift configuration of an aircraft equipped with internally blown Coanda flaps. Result comparison with a 3D Reynolds-averaged Navier-Stokes reference model demonstrates the method’s capability to accurately predict global jet momentum, whereas local jet momentum evaluation remains an open challenge. |
| Autor(en) | Weiss, Tayson | Wolfgang, Heinze | Peter, Horst |
|---|---|
| Titel | Influence of Propeller Aerodynamics on Structural Wing Box Optimization in Integrated Preliminary Aircraft Desgin |
| Herausgeber | 31st AIAA Applied Aerodynamics Conference, San Diego, 2013 |
| Erscheinungsjahr | 2013 |
| Abstract | The present study evaluates the consideration of propeller slipstream effects in a structural optimization procedure as commonly used in integrated preliminary aircraft design. Therefore an optimization model comprising aerodynamic and structural analysis of an exemplary short range aircraft wing box is developed. The aerodynamic loads are calculated with a potential-based 3D-panel code employing an actuator disk vortex tube and membrane arrangement for reflection of the propeller slipstream influence. Structural analysis is provided by means of a finite element model. The comparison of stress distributions and wing box masses obtained with and without incorporation of the propeller slipstream model indicate a distinct influence of the latter on the optimization result and thus on the entire underlying preliminary aircraft design process. |
| Autor(en) | Werner-Spatz, Christian | Heinze, Wolfgang | Horst, Peter | Radespiel, Rolf |
|---|---|
| Titel | Multidisciplinary conceptual design for aircraft with circulation control high-lift systems |
| Herausgeber | CEAS Aeronautical Journal, Volume 3,Issue 2-4, Springer-Verlag, pp 145-164 |
| Erscheinungsjahr | 2012 |
| Abstract | Active high-lift technologies have often proven their potential in aerodynamic analyses and wind tunnel tests, but have so far played only a minute role in civil production aircraft. This is expected to change in the future only if such technologies can be accounted for early in the aircraft design process. In this paper, the adaptation of a conceptual design process is presented, enabling it to consider circulation control as a high-lift technology. It is shown that the main aerodynamic effects of a blown flap in the boundary layer control regime can be satisfactorily modeled with a potential theory method. Some sample results of the design process indicate a potential for significant reductions of required field length in comparison with today’s aircraft, creating the potential to increase the capacity of the air transportation system, without increasing overall aircraft mass or direct operating cost. |