Nonlinear Aeroelastic Study of Bending Divergence

2010 ◽  
Author(s):  
Ghalib Y. Thwapiah ◽  
L. Flavio Campanile
Keyword(s):  
Large Deformations ◽  
Wind Tunnel Test ◽  
Experimental Tests ◽  
Research Trend ◽  
System Response ◽  
History Of ◽  
Compliant Systems ◽  
New Research ◽  
Wing Morphing ◽  
In The Beginning

In the beginning of the history of aviation, aeroelastic static instabilities were a problem in operating monoplane aircraft. After being discovered, they have been systematically avoided by design, since they would have led to large deformations and structural failure. A new research trend (active aeroelasticity) reverts this approach and utilizes — instead of avoiding — static instabilities to realize wing morphing. Another modern research trend are compliant systems (i.e. structures designed to achieve large deformations within its elastic range). Joining those two trends lead to a novel class of airfoil structures (compliant, active aeroelastic wings) enables operating at and beyond aeroelastic instabilities. Such structures need a new modeling approach, which includes nonlinearities of structural and aerodynamic kind. In this paper, a non linear analysis of aeroelastic bending divergence (a phenomenon which concerns forward-swept wings) is presented, initially based on so-called low-fidelity models. Such models are to some extent inaccurate, but allow a good insight into the physical behavior of the phenomenon. Experimental tests of a compliant airfoil will then be presented, performed to investigate the trans-critical and post-critical response of the airfoil model and to validate the low fidelity models. At the end, high-fidelity modeling is approached, which makes use of computational numerical simulations methods (FEM, CFD, FSI). Selected results will be presented, which allow to predict the system response more accurately and to reproduce the wind tunnel test results more closely.

Experimental and Numerical Investigations on Nonlinear Aeroelasticity of Forward-Swept, Compliant Wings

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Ghalib Y. Thwapiah ◽  
L. Flavio Campanile
Keyword(s):  
Large Deformations ◽  
System Response ◽  
High Fidelity Simulation ◽  
Structural Failure ◽  
Nonlinear Aeroelasticity ◽  
Aeroelastic Response ◽  
Innovative Idea ◽  
Compliant Systems ◽  
Wing Morphing ◽  
Swept Wings

At the beginning of aviation history, aeroelastic static instabilities represented a problem in operating monoplane aircraft. After being discovered, they were systematically avoided, since they would have led to large deformations and structural failure. A new idea (active aeroelasticity) reverts this approach and utilizes static instabilities to realize wing morphing instead of avoiding them. Another innovative idea (compliant systems) deals with structures designed to achieve large deformations within the elastic range of the material. Joining those two ideas leads to a novel class of airfoil structures (active aeroelastic, compliant airfoils) which enable operation at and beyond aeroelastic instabilities. Such structures need a new modeling approach, which includes nonlinearities of structural and aerodynamic kinds. In this paper, a non linear analysis of aeroelastic bending divergence (a phenomenon which concerns forward-swept wings) is presented, initially based on so-called low-fidelity models. Such models are, to some extent, inaccurate but allow a good insight into the physical behavior of the phenomenon and are very useful in preliminary design. The results of wind-tunnel tests follow, which were performed to investigate the aeroelastic response of a compliant airfoil model near divergence. Finally, high fidelity simulation results based on state-of-the-art methods (finite element method and fluid-structure-interaction) are shown and discussed. Those tools allow the prediction of the system response more accurately and are therefore well suited to the detailed design of active aeroelastic, compliant airfoils.

scholarly journals The Dnipropetrovsk “Vsesvitnyks” of the Later Soviet Time in the Memoirs of Serhii Plohii

2020 ◽  
pp. 181-205
Author(s):  
A. Venher
Keyword(s):  
Internal State ◽  
Academic Career ◽  
World History ◽  
Research Trend ◽  
Historical Science ◽  
Wide Range ◽  
History Of ◽  
Soviet Time ◽  
State Of Affairs ◽  
New Research

The development of national historical science attracts the attention of modern researchers as the study of “roots” allows to understand the current state of affairs in historical science. The study of individual corporations of historians in the areas of their research gives the opportunity to trace the internal state of things in national and world historical science. These studies can be carried due to the involvement and synthesis of a wide range of sources. The study of the corporation of Ukrainian Soviet historians opens additional perspectives to the researcher in expanding the source base. Namely, to promote the creation of new sources - memories. This publication presents the memoirs of the workshop of Dnipropetrovsk vsesvitnyks of the Ukrainian-American historian Serhii Plohii. In the Dnipropetrovsk period of life, the historian was part of it and headed it for some time. Memoirs that are introduced to the scientific circulation are written by the author from several perspectives: the student and the employee, and the third, the autobiographical, which goes through these two perspectives. Serhii Plokhii explains, from the perspective of the student, why he had chosen the department of world history to specialize in, characterizes the relations with his research supervisor Yuriy Mytsyk, and defines how his scientific carrier was influenced by Yakiv Rubin, the head of the department of world history in 1940-1950s. S. Plokhii characterizes the lecturers of the department, particularly the professor Vasyl` Syrotenko. From the perspective of the colleague, Plokhii describes the relations within the scientific community of the department, especially between different generations of lecturers. He characterizes his scientific interests and experience of being lecturer and administrator. Plokhii describes how the new research trend of the department of world history – history of the German Diaspora – emerged, and speaks about the start of PhD research in this field. Plokhii also defined the reasons why he had to abandon the Dnipropetrovsk University and started the academic career abroad.

Nonlinear Aeroelastic Behaviour of Compliant Airfoils

2009 ◽  
Author(s):  
Ghalib Y. Thwapiah ◽  
Flavio L. Campanile
Keyword(s):  
Wind Tunnel ◽  
Large Deformations ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Linear Approach ◽  
Innovative Idea ◽  
Compliant Systems ◽  
Observed Behaviour ◽  
Analytic Prediction ◽  
Good Agreement

Since begin of the aviation and up to the present times, airfoils have always been built as rigid structures. They are designed to fly under their divergence speed in order to avoid static aeroelastic instabilities and the resulting large deformations which are not compatible with the typically low compliance of such airfoils. In recent years, research on airfoil morphing has generated interest in innovative ideas like the use of compliant systems, i.e. systems built to allow for large deformations without failure, in airfoil construction. Such systems can operate in the neighbourhood of divergence and take advantage of large aeroelastic servo-effects. This, in turn, could allow compact, advanced actuators to control the airfoil’s deformation and loads, and hence complement or even replace conventional flaps. In order to analyze and design such compliant, active aeroelastic structures a non-linear approach to static aeroelastic is needed, which takes into account the effect of large deformations on aerodynamics and structure. Such an analytical approach is presented in this paper and applied to a compliant passive airfoil as the preliminary step to the realisation of a piezoelectrically driven, active aeroelastic airfoil. Wind-tunnel test results are also presented and compared with the analytic prediction. The good agreement and the observed behaviour in the wind tunnel give confidence in the potential of this innovative idea.

FBI and Religion

2017 ◽  
Keyword(s):  
Religious Orientation ◽  
Religious Communities ◽  
Academic Scholarship ◽  
History Of ◽  
Interdisciplinary Assessment ◽  
Civic Religion ◽  
New Research ◽  
The Relationship ◽  
The Way

This volume is an interdisciplinary assessment of the relationship between religion and the FBI. We recount the history of the FBI’s engagement with multiple religious communities and with aspects of public or “civic” religion such as morality and respectability. The book presents new research to explain roughly the history of the FBI’s interaction with religion over approximately one century, from the pre-Hoover period to the post-9/11 era. Along the way, the book explores vexed issues that go beyond the particulars of the FBI’s history—the juxtaposition of “religion” and “cult,” the ways in which race can shape the public’s perceptions of religion (and vica versa), the challenges of mediating between a religious orientation and a secular one, and the role and limits of academic scholarship as a way of addressing the differing worldviews of the FBI and some of the religious communities it encounters.

From the History of the Public Library in the Village Tagai of Simbirsk District in Simbirsk Province

2010 ◽  
pp. 102-106
Author(s):  
Valentina M. Patutkina
Keyword(s):  
Public Library ◽  
Library History ◽  
The Public ◽  
Ulyanovsk Region ◽  
History Of ◽  
In The Beginning ◽  
The Village

The article is dedicated to unknown page in the library history of Ulyanovsk region. The author writes about the role of Trusteeship on people temperance in opening of libraries. The history of public library organized in the beginning of XX century in the Tagai village of Simbirsk district in Simbirsk province is renewed.

Clause Structure and Word Order in the History of German

2018 ◽  
Keyword(s):  
Word Order ◽  
Left Periphery ◽  
Structural Factors ◽  
Clause Structure ◽  
Verb Second ◽  
Verb Forms ◽  
History Of ◽  
New Research ◽  
The Right ◽  
Theoretical Analyses

Over roughly the last decade, there has been a notable rise in new research on historical German syntax in a generative perspective. This volume presents a state-of-the-art survey of this thriving new line of research by leading scholars in the field, combining it with new insights into the syntax of historical German. It is the first comprehensive and concise generative historical syntax of German covering numerous central aspects of clause structure and word order, tracing them throughout various historical stages. Each chapter combines a solid empirical basis and valid descriptive generalizations with reference also to the more traditional topological model of the German clause with a detailed discussion of theoretical analyses couched in the generative framework. The volume is divided into three parts according to the main parts of the clause: the left periphery dealing with verbal placement and the filling of the prefield (verb second, verb first, verb third orders) as well as adverbial connectives; the middle field including discussion of pronominal syntax, order of full NPs and the history of negation; and the right periphery with chapters on basic word order (OV/VO), prosodic and information-structural factors, and the verbal complex including the development of periphrastic verb forms and the phenomena of IPP (infinitivus pro participio) and ACI (accusativus cum infinitivo). This book thus provides a convenient overview of current research on the major issues concerning historical German clause structure both for scholars interested in more traditional description and for those interested in formal accounts of diachronic syntax.

scholarly journals Ernst von Leyden (1832–1910): a pioneer in making oncology a respected medical discipline

2021 ◽  
Author(s):  
Peter Voswinckel ◽  
Nils Hansson
Keyword(s):  
International Association ◽  
German Society ◽  
Scientific Discipline ◽  
Strong Impact ◽  
Medical Discipline ◽  
History Of ◽  
National Socialists ◽  
New Research ◽  
German Physician

Abstract Purpose This article presents new research on the role of the renowned German physician Ernst von Leyden (1832–1910) in the emergence of oncology as a scientific discipline. Methods The article draws on archival sources from the archive of the German Society of Haematology and primary and secondary literature. Results Leyden initiated two important events in the early history of oncology: the first international cancer conference, which took place in Heidelberg, Germany, in 1906, and the founding of the first international association for cancer research (forerunner of today's UICC) in Berlin in 1908. Unfortunately, these facts are not mentioned in the most recent accounts. Both had a strong impact on the professionalization of oncology as a discipline in its own right. Conclusion Although not of Jewish origin, von Leyden was considered by the National Socialists to be “Jewish tainted”, which had a lasting effect on his perception at home and abroad.

The Mechanical Behavior of Aluminium Alloy Quenching Process

2011 ◽  
Vol 228-229 ◽  
pp. 822-827
Author(s):  
Jia Yuan Luo ◽  
Rong Fan ◽  
Cheng Xiang Shi
Keyword(s):  
Surface Layer ◽  
Aluminum Alloy ◽  
Dynamic Simulation ◽  
Strain Field ◽  
Method Development ◽  
Experimental Tests ◽  
Analysis Method ◽  
Process Dynamic ◽  
Quenching Process ◽  
History Of

Since the aluminum alloy quenching is a complicated and a prompt heat-pressure coupling processing, traditional experimental tests and empirical judgments cannot explain and predict the physical and the force behavior completely during the quenching process. Dynamic simulation of the quenching process is conducted using the finite analysis method. Development laws of the stress and the strain field of the surface layer and core of the alloy during the quenching process are described based on the verification of the simulation. States and process history of the stress and the strain in each phase during the quench are obtained, which provides ponderable data and theoretical value for a fully understanding of the aluminum alloy quenching.

New Zealand translocations: theory and practice

1995 ◽  
Vol 2 (1) ◽  
pp. 39 ◽  
Author(s):  
Doug P. Armstong ◽  
Ian G. McLean
Keyword(s):  
Population Dynamics ◽  
New Zealand ◽  
Experimental Tests ◽  
Theory And Practice ◽  
Habitat Requirements ◽  
Metapopulation Dynamics ◽  
Behavioural Adaptation ◽  
New Locations ◽  
History Of ◽  
Tests Of Hypotheses

One of the most common tools in New Zealand conservation is to translocate species to new locations. There have now been over 400 translocations done for conservation reasons, mainly involving terrestrial birds. Most translocations have been done strictly as management exercises, with little or no reference to theory. Nevertheless, translocations always involve some underlying theory, given that people must inevitably choose among a range of potential translocation strategies. We review theory relevant to translocations in the following areas: habitat requirements, susceptibility to predation, behavioural adaptation, population dynamics, genetics, metapopulation dynamics, and community ecology. For each area we review and evaluate the models that seem to underpin translocation strategies used in New Zealand. We report experiments testing some of these models, but note that theory underlying translocation strategies is largely untested despite a long history of translocations. We conclude by suggesting key areas for research, both theoretical and empirical. We particularly recommend that translocations be designed as experimental tests of hypotheses whenever possible.

Continuities and Discontinuities: New Research on the History of German Economic Institutions

2005 ◽  
Vol 14 (4) ◽  
pp. 591-602
Author(s):  
CHRISTOPHER KOPPER
Keyword(s):  
Economic Institutions ◽  
Cambridge University ◽  
Oxford University ◽  
History Of ◽  
New Research ◽  
Oxford University Press

Werner Abelshauser, Jan-Otmar Hesse and Werner Plumpe, eds., Wirtschaftsordnung, Staat und Unternehmen. Neue Forschungen zur Wirtschaftsgeschichte des Nationalsozialismus (Essen: Klartext Verlag, 2003), 392 pp., €29.80 (pb), ISBN 3898612597.Conan Fischer, The Ruhr Crisis 1923–1924 (Oxford: Oxford University Press, 2003), £55.00 (hb), ISBN 0198208006.Harold James, The Deutsche Bank and the Economic War against the Jews (Cambridge: Cambridge University Press, 2001), 268 pp., £27.50 (hb), ISBN 0521803292.Reinhard Spree, ed.,Geschichte der deutschen Wirtschaft im 20.Jahrhundert (Munich: C. H. Beck, 2001), 232 pp., €12,50 (pb), ISBN 3406475698.Hans Erich Volkmann, Ökonomie und Expansion. Grundzüge der NS-Wirtschaftspolitik (Munich: R. Oldenbourg Verlag, 2003), €39.80 (hb), ISBN 3486567144

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