Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Download Aircraft Wake Vortex Scenarios Simulation Package Wakescene full books in PDF, epub, and Kindle. Read online Aircraft Wake Vortex Scenarios Simulation Package Wakescene ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author : Frank Holzäpfel
Publisher :
ISBN 13 :
Total Pages : 17 pages
Book Rating : 4.:/5 (18 download)
Download or read book Aircraft Wake Vortex Scenarios Simulation Package - Wakescene written by Frank Holzäpfel and published by . This book was released on 2007 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Ulrich Schumann
Publisher : Springer Science & Business Media
ISBN 13 : 3642301835
Total Pages : 884 pages
Book Rating : 4.6/5 (423 download)
Download or read book Atmospheric Physics written by Ulrich Schumann and published by Springer Science & Business Media. This book was released on 2012-07-17 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the occasion of the 50th anniversary of the Institute of Atmospheric Physics of the German Aerospace Center (DLR), this book presents more than 50 chapters highlighting results of the institute’s research. The book provides an up-to-date, in-depth survey across the entire field of atmospheric science, including atmospheric dynamics, radiation, cloud physics, chemistry, climate, numerical simulation, remote sensing, instruments and measurements, as well as atmospheric acoustics. The authors have provided a readily comprehensible and self-contained presentation of the complex field of atmospheric science. The topics are of direct relevance for aerospace science and technology. Future research challenges are identified.
Author : National Research Council
Publisher : National Academies Press
ISBN 13 : 0309113792
Total Pages : 102 pages
Book Rating : 4.3/5 (91 download)
Download or read book Wake Turbulence written by National Research Council and published by National Academies Press. This book was released on 2008-04-27 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Without major changes, the current air transportation system will be unable to accommodate the expected increase in demand by 2025. One proposal to address this problem is to use the Global Positioning System to enable aircraft to fly more closely spaced. This approach, however, might be limited by the wake turbulence problem, which can be a safety hazard when smaller aircraft follow relatively larger aircraft too closely. To examine how this potential hazard might be reduced, Congress in 2005 directed NASA to request a study from the NRC to assess the federal wake turbulence R&D program. This book provides a description of the problem, an assessment of the organizational challenges to addressing wake turbulence, an analysis of the technical challenges in wake turbulence, and a proposal for a wake turbulence program plan. A series of recommendations for addressing the wake turbulence challenge are also given.
Author : A.S. Ginevsky
Publisher : Springer Science & Business Media
ISBN 13 : 3642017606
Total Pages : 166 pages
Book Rating : 4.6/5 (42 download)
Download or read book Vortex wakes of Aircrafts written by A.S. Ginevsky and published by Springer Science & Business Media. This book was released on 2009-07-07 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing’s trailing edge are long lived and attenuate only atdistances of10–12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft’s encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport’s ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft’s movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier–Stokes equations, large eddy simulation using the Navier–Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries’ scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.
Author : Daniel Guy Schauerhamer
Publisher :
ISBN 13 : 9780355763850
Total Pages : pages
Book Rating : 4.7/5 (638 download)
Download or read book Simulating the Lifecycle of Aircraft Wake Vortices written by Daniel Guy Schauerhamer and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To better understand aircraft wake behavior with the goal to increase flight safety and airport capacity, the aircraft wake vortex lifecycle was simulated using computational fluid dynamics. Using a build-up approach, best practices for wing-tip vortex roll-up were developed starting with a simple inviscid vortex, and building up in complexity to a finite wing and full aircraft. Validation of the best practices was accomplished with comparisons to wind tunnel data. Best practices were then applied to the German Aerospace Center F11 wind tunnel model and the NASA Common Research Model with validation of results with wind tunnel measurements. Vortex sensitivity to aircraft configuration were explored by changing the details of the F11 model, and by adding a generic winglet to the Common Research Model. Results demonstrated that the wake vortex changed significantly with aircraft configuration. The wake of the Common Research Model was used to initialize two-dimensional evolution studies which propagated the wake system to 10 wing spans downstream. Best practices were developed to demonstrate low numerical error and the computational savings of using adaptive mesh refinement. Three-dimensional simulations were carried out with the Common Research Model to resolve 10 wing spans downstream, however with a coarser-than-desired mesh due to computational limitations. The solution was used to initialize three-dimensional decay simulations. A testbed case of wake vortex decay was used to develop best practices and quantify error sources for decay simulations in a cost-effective manner. Those best practices were applied to the Common Research Model decay simulation. Results throughout the research were compared to idealized vortex models that in practice are used to initialize decay simulations. For all comparisons, including the aircraft effects resulted with significant differences to the idealized vortex models. Including the aircraft effects in the simulations resulted in more accurate wake results.
Author :
Publisher :
ISBN 13 :
Total Pages : 18 pages
Book Rating : 4.:/5 (317 download)
Download or read book A Preliminary Study of a Wake Vortex Encounter Hazard Boundary for a B737-100 Airplane written by and published by . This book was released on 1996 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : David K. Rutishauser
Publisher :
ISBN 13 :
Total Pages : 28 pages
Book Rating : 4.:/5 (317 download)
Download or read book Aircraft Wake Vortex Spacing System (AVOSS) Performance Update and Validation Study written by David K. Rutishauser and published by . This book was released on 2001 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis has been performed on data generated from the two most recent field deployments of the Aircraft Wake Vortex Spacing System (AVOSS). The AVOSS provides reduced aircraft spacing criteria for wake vortex avoidance as compared to the FAA spacing applied under Instrument Flight Rules (IFR). Several field deployments culminating in a system demonstration at Dallas Fort Worth (DFW) International Airport in the summer of 2000 were successful in showing a sound operational concept and the system's potential to provide a significant benefit to airport operations. For DFW, a predicted average throughput increase of 6% was observed. This increase implies 6 or 7 more aircraft on the ground in a one-hour period for DFE operations. Several studies of performacne correlations to system configuration options, and system inputs are also reported. The studies focus on the validation performance of the system.
Author : Jongil Han
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (11 download)
Download or read book Large Eddy Simulation of Aircraft Wake Vortices in a Homogeneous Atmospheric Turbulence written by Jongil Han and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : T. E. Sullivan
Publisher :
ISBN 13 :
Total Pages : 72 pages
Book Rating : 4.:/5 (1 download)
Download or read book Aircraft Wake Vortices written by T. E. Sullivan and published by . This book was released on 1990 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : David A. Hinton
Publisher :
ISBN 13 :
Total Pages : 38 pages
Book Rating : 4.:/5 (317 download)
Download or read book A Candidate Wake Vortex Strength Definition for Application to the NASA Aircraft Vortex Spacing System (AVOSS) written by David A. Hinton and published by . This book was released on 1997 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Omer Ali El-Sayed
Publisher :
ISBN 13 :
Total Pages : 360 pages
Book Rating : 4.:/5 (957 download)
Download or read book Aircraft Wake Vortices Characterization and Alleviation written by Omer Ali El-Sayed and published by . This book was released on 2010 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The serious impact of the trailing vortices from large aircraft is well known. Many examples exist of the damage caused to following aircraft caught up in the swirling wake shed from an upstream aircraft. Motivation behind the present investigation is the alleviation of the rolling moment induced on the following aircraft by means of a differential spoiler setting DSS's. An experimental investigation on a wing tip vortex generated by generic aircraft model, Subsonic Wall Interference Model (SWIM) in plain and flapped wing configurations was conducted in a low speed wind tunnel at Korean Aerospace Research Institute (KARI). Particle image velocimetry was used to characterize wing tip vortex structures as well as to distinguish and quantify vortex meandering and further remove its effects. In subsequent experiments investigation on wake vortices has been carried out in the international Islamic University Malaysia (IIUM) low speed wind tunnel for the evaluation of differential spoiler settings (DSS) capabilities in modifying the span-wise wing load and further reduces the wake vortex hazard. Advanced PIV technique was used to measure the wake velocities at four cross-section planes down-stream of the aircraft half model in the near and extended near wake field. Model was investigated at high lift configuration as well as at four DSS configurations believed to modify the span-wise wing loading (two inboard and two outboard loading cases). Results reveal a noticeable inboard shift of wing loading along with the direct interaction of the spoiler's wake and flap tip vortex for the inboard loading cases. Implementation of DSS results in a substantial redistribution of the flap tip vortex circulation with a diameter of the merged vortex increased by a factor of up to 2.72 times, relative to the undisturbed flap tip vortex. Inspection of the cross-stream distribution of axial vorticity shows up to 2.33 times reduction in the peak vorticity value. A 44% decrease of the maximum cross-flow velocity was recorded for the case of deployed spoilers relative to undisturbed flap tip vortex maximum cross-flow velocity. The wing tip vortex experiences the effect of wing load modification but doesn't show appreciable difference, both in terms of cross-flow velocity and local circulation distribution. Evaluations of the outboard loading results indicate a limited diffusion experienced by the vortex due to the increased level of turbulence. Influence of DSS's on the wake vortex structure emphasizes that separation distance (spoiler wake/wing-flap tips vortices) plays an important role in the favorable interaction expected. Finally assessment of the DSS's capabilities as a wake vortex attenuation device reveals, while position of the maximum induced rolling moments in the flap tip area is little influenced by the DSS's, the maximum induced rolling moment coefficient was reduced to a nearly one third relative to the undisturbed flap tip vortex value.
Download or read book Wake Vortex Modelling and Simulation for Air Vehicles in Close Formation Flight written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this research is to develop realistic models of aerodynamic cross-coupling e ects that can be incorporated in real-time or near real-time simulations of Unmanned Aerial Vehicles (UAVs) in close formation flight. These would permit the assessment of the risks and issues associated with wake vortex evolution and encounter and the analysis of their consequences on the design of automatic control systems and the development of safe and reliable operating procedures. A number of wake vortex modelling techniques that can be used in formation flight simulations are reviewed. A novel Wake Vortex Model (WVM) is developed, implemented, verified, validated and successfully integrated within a Matlab/Simulink simulation environment. The code, named ELL because it is based on Weissinger's extended lifting line theory, meets the following requirements: (i) it is generic and can easily be adapted to accomodate any wing planform and air vehicle configuration; (ii) it is computationally rapid enough to be used in real-time or near real-time simulations; (iii) and it is sufficiently representative to support studies of aerodynamic interaction between multiple air vehicles during formation reconfiguration and air-to-air refuelling simulations. Simulink test scenarios of two Aerosonde UAVs are developed to test and validate the use of ELL within simulation models, and the simulation environment is interfaced with visualisation tools in order to facilitate the evaluation of multiple air vehicle dynamic interaction.
Author :
Publisher :
ISBN 13 :
Total Pages : 550 pages
Book Rating : 4.:/5 (1 download)
Download or read book Proceedings of the Aircraft Wake Vortices Conference, Washington, D.C., October 29-31, 1991 written by and published by . This book was released on 1992 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Jeffrey A. Boyd
Publisher :
ISBN 13 :
Total Pages : 314 pages
Book Rating : 4.:/5 (214 download)
Download or read book A Methodology for Analyzing an Aircraft Wake Vortex Encounter written by Jeffrey A. Boyd and published by . This book was released on 2008 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Hani bin Ludin @ Jamaluddin
Publisher :
ISBN 13 :
Total Pages : 238 pages
Book Rating : 4.:/5 (957 download)
Download or read book Numerical Study of Wake Vortex Alleviation written by Hani bin Ludin @ Jamaluddin and published by . This book was released on 2012 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical investigation was undertaken to study the aerodynamic characteristics of wake vortices generated from an aircraft during taking-off or landing, and thus exploring the possible techniques of reducing hazard imposed to the following aircraft by means of passive wake vortex alleviation. An initial study has been carried out on passive wake vortex alleviation by using delta wing (DW) and reverse delta wing (RDW) as an add-on device. Simulations were performed using RANS turbulence model. The results were obtained and quantified at measurement section locations downstream, of x/c=1.359 and x/c=3.418 measured from leading edge point of the model. Comparison between numerical and experimental results has shown good agreement in term of aerodynamic forces for RDW, whereas the comparison is not so good for DW as far as the prediction of drag coefficient is concerned. Although the simulations capture vortex roll-up trends, the size of the vortex is not predicted correctly by RANS turbulence model. Overall, it can be concluded from the results that the wake vortex generated from DW exhibit higher tangential velocity magnitude and circulation than the one generated from RDW at a particular angle of attack (AOA) between 20o to 30o. Subsequently, a broader investigation of another passive wake vortex alleviation technique was performed to study the potential of differential spoiler setting (DSS) of a scaled, half-model aircraft in alleviating the rolling moment induced on the following aircraft. The model was simulated under high lift configuration (HLC) condition, using inherently unsteady technique adopted in LES turbulence model, for two outboard loading cases and two inboard loading cases, in addition to the baseline configuration case. The study has covered near-wake field and extended near-wake field by taking seven measurement section planes at x/b=0.345, x/b=0.444, x/b=0.658, x/b=1.076, x/b=1.794, x/b=2.691 and x/b=4.484. Comparison between numerical simulations and experimental results has shown good agreement in term of lift coefficient for all cases, and fairly acceptable agreement in term of maximum cross-flow velocity, maximum normalized total circulation and maximum induced rolling moment. However, there were some occasions where the comparison is not so good. For instance, the difference error has risen up to 40.3% in term of maximum normalized cross-flow velocity for baseline configuration. Evaluation of the results has showed promising outcomes for the inboard loading cases compared to the outboard loading cases. The interaction between spoilers' wake and outboard flap tip vortex of the inboard loading cases has reduced the tangential velocity magnitude and circulation of the wing tip vortex, and delayed vortex merging to farther distance downstream. This conclusion justifies the DSS's capabilities in wake vortex alleviation. Therefore, DSS can be considered as one of the promising techniques that can be used commercially in the future.
Author :
Publisher :
ISBN 13 :
Total Pages : 108 pages
Book Rating : 4.3/5 (555 download)
Download or read book Aircraft Wake Vortex Takeoff Tests at O'Hare International Airport written by and published by . This book was released on 1994 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Carles Suñer Perucho
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (112 download)
Download or read book Aircraft Dynamic Loads Generated in Wake Vortex Encounters written by Carles Suñer Perucho and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study illustrated in these pages was developed in the Structural Dynamics and Aeroelasticity Department of the Military Aircraft division of Airbus Defence and Space in Getafe, Madrid (Spain). That department is a multidisciplinary one involving several categories. Some of its competences are the analysis of impacts, acoustics and vibrations for the aircraft and all their systems. Also, the dynamic response of the aircraft to different events is part of the tasks for that department. It is in that field where this project is located. Wake vortex encounters are a dynamic phenomenon similar to other excitations faced by aircraft in its usual operation. That excitation will induce dynamic loads in the aircraft structures as it passes through the wake. Obtaining and analyzing those loads are the main aims of this study. First, it is important to introduce the concept of aircraft wake. In order to achieve the goals of the study, it is necessary to start with the basics of the problem. This is the acknowledgement of the physics of aircraft wakes and how they are generated. Then, how those wakes act as an excitation for other aircraft as they perturb the velocity field of the air. Once the aircraft wakes are introduced, the next step consists of explaining the corresponding aircraft that will face those encounters. In this case, the particular aircraft is an Airbus A400M because that was the one used by Airbus Defence and Space in the campaign of the wake vortex encounters. The following considerations involve the procedures of the Structural Dynamics department in the computation of the numerical simulation for that kind of event. Therefore, it is necessary to know what the tools available for the resolution of this problem are and which aspects face each one. Furthermore, the software and models used in this study have been validated with flight tests and they are an excellent representation of the aircraft and problem considered. After the presentation of the problem, the aircraft considered and tools used, the wake model is the next aspect of study. This is one of the widest fields of aircraft wakes. Having a good wake model is necessary for the accuracy of the results and the main tasks are focused on the wake aging model. That is how the wake evolves and changes as times goes by. With all that, the last aspect of this study is the computation of the dynamic loads induced in wake vortex encounters. As it is an event that is not considered in aircraft regulations, it was difficult to define a particular scenario that is representative of the problem. For that reason, a stochastic analysis of the problem has been chosen to obtain the aircraft loads generated in this kind of event. This analysis consists of scattering the input variables affecting the problem and executing a high number of simulations. In that way, it is possible to derive a statistical behavior of the load response and establish a probability of occurrence for the results obtained. Finally, comparing those results with the reference loads of the aircraft, it is feasible to predict whether wake vortex encounters could be a significant event for the aircraft structure during its operational life.
