Download or read book Transonic Flutter Prediction and Aeroelastic Tailoring for Next generation Transport Aircraft written by Max Maria Jacques Opgenoord and published by . This book was released on 2018 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel commercial transport aircraft concepts feature large wing spans to increase their fuel efficiency; these wings are more flexible, leading to more potential aeroelastic problems. Furthermore, these aircraft fly in the transonic flow regime, where utter prediction is difficult. The goals for this thesis are to devise a method to reduce the computational burden of including transonic utter constraints in conceptual design tools, and to offer a potential solution for mitigating utter problems through the use of additive manufacturing techniques, specically focusing on a design methodology for lattice structures. To reduce the computational expense of considering transonic utter in conceptual aircraft design, a physics-based low-order method for transonic utter prediction is developed, which is based on small unsteady disturbances about a known steady flow solution. The states of the model are the circulation and doublet perturbations, and their evolution equation coefficients are calibrated using off-line unsteady two-dimensional flow simulations. The model is formulated for swept high-aspect ratio wings through strip theory and 3D corrections. The resulting low-order unsteady flow model is coupled to a typical-section structural model (for airfoils) or a beam model (for wings) to accurately predict utter of airfoils and wings. The method is fast enough to permit incorporation of transonic utter constraints in conceptual aircraft design calculations, as it only involves solving for the eigenvalues of small state-space systems. This model is used to describe the influence of transonic utter on next generation aircraft configurations, where it was found that transonic utter constraints can limit the eciency gains seen by better material technology. As a potential approach for mitigating utter, additively manufactured lattice structures are aeroelastically tailored to increase the flutter margin of wings. Adaptive meshing techniques are used to design the topology of the lattice to align with the load direction while adhering to manufacturing constraints, and the lattice is optimized to minimize the structural weight and to improve the flutter margin. The internal structure of a wing is aeroelastically tailored using this design strategy to increase the flutter margin, which only adds minimal weight to the structure due to the large design freedom the lattice structure offers.
Download or read book Future Research on Transonic Unsteady Aerodynamics and Its Aeroelastic Applications written by ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (France) and published by . This book was released on 1987 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Workshop focused on strategies for promoting and developing engineering-level transonic flutter prediction techniques. The technology of transonic aerodynamics is currently undergoing rapid development. Significant progress is being made to solve the inherently nonlinear equations describing unsteady motions of wings in transonic flow, while the availability of reliable and efficient computational methods will greatly enhance the ability to predict the aeroelastic behaviour of modern aircraft operating under transonic flow conditions. AGARD-SMP has previously coordinated unsteady aerodynamic research carried out on a number of standard wind tunnel model configurations and published the results. The proposals contained in the Evaluation Report (W.J. Mykytow) on the Fall 1984 Structures and Materials Panel Specialists' Meeting on Transonic Unsteady Aerodynamics, together with an expanded range of aeroelastic configurations, formed the guidelines which this Workshop followed.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Optimization of Highly Flexible Aircraft with Aeroelastic Constraints written by Anil Variyar and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the need to drastically reduce aircraft emissions and fuel burn, there have been significant strides towards the design of fuel-efficient aircraft. This has involved moving towards extremely high aspect-ratio wings that need to be aeroelastically tailored and unconventional aircraft configurations. However aeroelastic stability of such configurations is a major challenge. In order to ensure that the fuel-burn improvements predicted in the conceptual or early preliminary design phase are attained in reality, it is essential to ensure that aeroelastic constraints are enforced early on in the design phase itself. However inexpensive yet accurate computation of transonic aeroelasticity especially transonic flutter predictions is quite a challenge due to the non-linearity in the flow at transonic regimes which requires non-linear fluid dynamics approaches that are generally too expensive for the early design phases. In this work we attempt to address this issue by first developing a two-dimensional parametric transonic low-order model that accurately predicts unsteady flow results for airfoils. A set of airfoil agnostic parameters for this model are obtained that permit accurate two-dimensional transonic aeroelastic simulations. This approach is then extended into three dimensions using the ASWING Weissinger model formulation. Next a set of in-house capabilities are developed that permit the inclusion of this approach into a conceptual design loop. Finally a number of flutter constrained optimizations are performed to understand the impact of imposing flutter constraints in an aircraft design/sizing loop.
Download or read book Recent Advances in Transonic Computational Aeroelasticity written by and published by . This book was released on 1988 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Transonic Small Disturbance Theory for Predicting the Aeroelastic Stability of a Flexible Wind tunnel Model written by and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Aeroelastic Methods to Predict Flutter Characteristics of Fighter Aircraft in the Transonic Speed Range written by Jos J. Meijer and published by . This book was released on 1995 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non linear Aeroelastic Predictions for Transport Aircraft written by T. W. Purcell and published by . This book was released on 1990 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1990 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AGARD Index of Publications written by Organisation du traité de l'Atlantique Nord. Groupe consultatif pour la recherche et le développement aérospatial. Technical Information Panel and published by . This book was released on 1995 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Aircraft Aeroelasticity and Loads written by Jan Robert Wright and published by John Wiley & Sons. This book was released on 2008-02-28 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeroelastic phenomena arising from the interaction of aerodynamic, elastic and inertia forces, and the loads resulting from flight / ground manoeuvres and gust / turbulence encounters, have a significant influence upon aircraft design. The prediction of aircraft aeroelastic stability, response and loads requires application of a range of interrelated engineering disciplines. This new textbook introduces the foundations of aeroelasticity and loads for the flexible aircraft, providing an understanding of the main concepts involved and relating them to aircraft behaviour and industrial practice. This book includes the use of simplified mathematical models to demonstrate key aeroelastic and loads phenomena including flutter, divergence, control effectiveness and the response and loads resulting from flight / ground manoeuvres and gust / turbulence encounters. It provides an introduction to some up-to-date methodologies for aeroelastics and loads modelling. It lays emphasis on the strong link between aeroelasticity and loads. It also includes provision of MATLAB and SIMULINK programs for the simplified analyses. It offers an overview of typical industrial practice in meeting certification requirements.
Download or read book Introduction to Nonlinear Aeroelasticity written by Grigorios Dimitriadis and published by John Wiley & Sons. This book was released on 2017-03-10 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Nonlinear Aeroelasticity Introduces the latest developments and technologies in the area of nonlinear aeroelasticity Nonlinear aeroelasticity has become an increasingly popular research area in recent years. There have been many driving forces behind this development, increasingly flexible structures, nonlinear control laws, materials with nonlinear characteristics and so on. Introduction to Nonlinear Aeroelasticity covers the theoretical basics in nonlinear aeroelasticity and applies the theory to practical problems. As nonlinear aeroelasticity is a combined topic, necessitating expertise from different areas, the book introduces methodologies from a variety of disciplines such as nonlinear dynamics, bifurcation analysis, unsteady aerodynamics, non-smooth systems and others. The emphasis throughout is on the practical application of the theories and methods, so as to enable the reader to apply their newly acquired knowledge Key features: Covers the major topics in nonlinear aeroelasticity, from the galloping of cables to supersonic panel flutter Discusses nonlinear dynamics, bifurcation analysis, numerical continuation, unsteady aerodynamics and non-smooth systems Considers the practical application of the theories and methods Covers nonlinear dynamics, bifurcation analysis and numerical methods Accompanied by a website hosting Matlab code Introduction to Nonlinear Aeroelasticity is a comprehensive reference for researchers and workers in industry and is also a useful introduction to the subject for graduate and undergraduate students across engineering disciplines.
Download or read book Aerodynamic Design of Transport Aircraft written by E. Obert and published by IOS Press. This book was released on 2009-04-16 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin of Aerodynamic Design of Transport Aircraft stems from the time when the author was appointed part-time professor in the Aerospace Faculty of Delft University of Technology. At the time his main activities were those of leading the departments of Aerodynamics, Performance and Preliminary Design at Fokker Aircraft Company. The groundwork for this book started in 1987 as a series of lecture notes consisting mainly of pictorial material with a minimum of English explanatory text. After the demise of Fokker in 1996 one feared that interest in aeronautical engineering would strongly diminish. As a result of this, the course was discontinued and the relationship between the author and the faculty came to an end. Two years later the situation was reappraised, and the interest in aeronautical engineering remained, so the course was reinstated with a former Fokker colleague Ronald Slingerland as lecturer. The lecture notes from these courses form the foundation of this publication.
Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Subsonic Airplane Design written by E. Torenbeek and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 607 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the education of aeronautical engineers at Delft University of Technology started in 1940 under tae inspiring leadership of Professor H.J. van der Maas, much emphasis has been placed on the design of aircraft as part of the student's curriculum. Not only is aircraft design an optional subject for thesis work, but every aeronautical student has to carry out a preliminary airplane design in the course of his study. The main purpose of this preliminary design work is to enable the student to synthesize the knowledge ob tained separately in courses on aerodynamics, aircraft performances, stability and con trol, aircraft structures, etc. The student's exercises in preliminary design have been directed through the years by a number of staff members of the Department of Aerospace Engineering in Delft. The author of this book, Mr. E. Torenbeek, has made a large contribution to this part of the study programme for many years. Not only has he acquired vast experience in teaching airplane design at university level, but he has also been deeply involved in design-oriented re search, e.g. developing rational design methods and systematizing design information. I am very pleased that this wealth of experience, methods and data is now presented in this book.
Download or read book Basic Flight Mechanics written by Ashish Tewari and published by Springer. This book was released on 2016-04-22 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents flight mechanics of aircraft, spacecraft, and rockets to technical and non-technical readers in simple terms and based purely on physical principles. Adapting an accessible and lucid writing style, the book retains the scientific authority and conceptual substance of an engineering textbook without requiring a background in physics or engineering mathematics. Professor Tewari explains relevant physical principles of flight by straightforward examples and meticulous diagrams and figures. Important aspects of both atmospheric and space flight mechanics are covered, including performance, stability and control, aeroelasticity, orbital mechanics, and altitude control. The book describes airplanes, gliders, rotary wing and flapping wing flight vehicles, rockets, and spacecraft and visualizes the essential principles using detailed illustration. It is an ideal resource for managers and technicians in the aerospace industry without engineering degrees, pilots, and anyone interested in the mechanics of flight.
