bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Dependence of Diffuser Performance upon Inlet Flow Conditions
Authors: Livesey J. L. , Turner J.T. 
Published: July 2016

It was recently stated by Cockrell, Diamond and Jones(1) that attempts to correlate diffuser loss coefficients with the inlet boundary layer momentum thickness were generally unsatisfactory. In particular, it had proved impossible to align various results from diffuser tests which had been made with differing inlet flow conditions. The two methods of thickening the diffuser inlet boundary layer, using either(a) a length of parallel pipe, or(b) screen rings at inlet to the diffuserled to a corresponding variation in diffuser performance.The conclusion was drawn that “the manner by which an inlet boundary layer has been thickened is as significant in determining diffuser performance as is the thickness of the layer. No satisfactory inlet flow parameter is at present known”.
Integral Axi-Symmetric Nozzle Design
Authors: Cohen M. J. 
Published: July 2016

SummaryThis is an extension of the design method described in ref. 1 to the compressible flow in integral nozzles comprising both subsonic (contraction) and supersonic (effusor) parts. The nozzles are axially symmetric and will be considered as isentropic convertors of low speed high enthalpy inviscid gas to a high speed, relatively low enthalpy state, heat transfer effects being ignored. The key advantage of the method over existing hybrid design methods(2'3'4'5) is that no assumption is made as to conditions in the “sonic” throat region before expansion in the effusor, the design being integral from low speed inlet to high speed outlet. A slight disadvantage of the method is that of ref 1, namely that a nozzle of an ideally infinite extent has to be truncated both at inlet and outlet. However, for a given nozzle length this limitation can be biased towards the relatively insensitive low subsonic inlet to benefit correspondingly outlet conditions to the extent that it should be possible to make the maximum variation from the mean in the cross-sectional speed at outlet less than 0.01 per cent. The method is being applied to design integral hypersonic nozzle units for the projected small intermittent hypersonic facility in the Department of Aeronautics and Space Technology. This tunnel will have a nominal working-section diameter of 2 in and the flow will be accelerated from low speed (about 20 ft/sec) at inlet to Mach numbers of either 5, 6, or 7 at outlet to the working section using three alternative nozzles.
Aerodynamically Induced Vibration in Coolers
Authors: Mabey D. C. 
Published: July 2016

Vortices shed from cooler tubes can excite standing pressure waves in coolers if the vortex shedding frequency coincides with the standing wave frequency(1, 2, 3, 4). If resonant conditions are encountered in a particular cooler the single vortex shedding frequency may be suppressed by fitting in-clined splitter plates into the coolers. These splitter plates also “detune” the coolers by raising the resonant frequencies.Splitter plates of this type were used recently to eliminate severe noise and structural vibration in a new cooler for the 3 ft wind tunnel at the Royal Aircraft Establishment, Bedford.
The Well-Balanced Structure
Authors: Pugsley Alfred 
Published: July 2016

The Fifty-Fourth Wilbur and Orville Wright Memorial Lecture, “The Well-Balanced Structure”, was given by Sir Alfred Pugsley, OBE, DSc, FRS, HonFRAeS, on 9th December 1965 in the Lecture Theatre, 4 Hamilton Place, London W.I. The Chair was taken by Sir George Gardner, KBE, CB, HonDSc, HonFRAeS, President of the Society, who opened the meeting by expressing the sympathy of the Society to their colleagues in America on the death of Dr. Hugh L. Dryden on 2nd December; not only was he a distinguished man in his own country but he was a close friend of many in this country and an Honorary Fellow of the Society.As has become the custom, the Society's main awards for the year were presented before the lecture. The presentations were made by the President and the citations were read by Mr. A. D. Baxter, MEng, FRAeS, President-Elect; the scrolls of three Honorary Fellowships and of two Honorary Companionships, and nine medals were presented. (The names of the new Honorary Fellows and Honorary Companions and the list of awards, with their citations, were published in the December 1965 Journal, pages LXXX and LXXXI.)Introducing the Lecturer, the President said that the year of the Wright Brothers’ first flight had been the year of birth of a number of people who had made great contributions to the development of aeronautics; one of these was Sir Alfred Grenvile Pugsley. He obtained a first class honours degree in engineering of London University and then trained as a civil engineer and Student apprentice at the Royal Arsenal, Woolwich; there could be no doubt about his full qualifications as a “chartered engineer” according to the new standards. In 1925 he joined the design and research staff at Cardington working on the R101 and not only had he played his part in the design of various parts of the airship's structure, he had also taken part in the full speed trials of the airship. In 1931 Sir Alfred joined the scientific staff of the Royal Aircraft Establishment and worked on structural problems, particularly in the field of aeroelasticity. From 1941 to 1945 he was head of the Structures and Mechanical Engineering Department at Farnborough.He was appointed Professor of Civil Engineering at the University of Bristol in 1945 and was Dean of the Faculty of Engineering from 1951-54, and Pro-Vice-Chancellor from 1961-64. Sir Alfred had acted successively on the Councils of the Royal Aeronautical Society, the Institution of Structural Engineers, the Institution of Civil Engineers and the Royal Society, and was President of the Institution of Structural Engineers in 1957-58. He was Chairman of the Aeronautical Research Council from 1952-57 and was a member of the Advisory Council for Scientific Policy from 1956-59. He was knighted in 1956 and was made an Honorary Fellow of the Society in 1963.
On the Aerodynamics of “Hangar” Type Engine Test Facilities
Authors: Wallis R. A. , Ruglen N. 
Published: July 2016

The present aerodynamic study of “hangar” type engine test cells originated with a request for assistance following difficulties experienced in the commissioning of a Dart engine-test facility. The major improvements obtained resulted from a systematic programme aimed at understanding the basic problems involved. Extensive use was made of model techniques during this investigation.Detailed flow studies in two other hangar type cells, in successful operation, disclosed certain vortex features which were common to all three cells. Hence in view of a dearth of information on the aerodynamics of such cells, it was decided to deal with the general design problem and to sup-port the study with selected results from the experimental work referred to previously.
An Investigation of Hovercraft Wavemaking
Authors: Hogben N. 
Published: July 2016

The main purpose of the investigation has been to clarify the definition of hovercraft wavemaking resistance and to improve understanding of the physical mechanism. The most literal definition of wave resistance as the force which makes the waves is proposed and its practical and theoretical implications are considered. Various interim accounts of this work have already been written, but the time now seems appropriate to assemble and review the overall picture which is emerging.The pattern of forces on a hovercraft over water is often difficult to analyse because of the complicated interaction between wavemaking, jet air momentum, cushion pressure, wetting and other effects. It is important, however, in making power predictions that the physical interpretation and corresponding scaling laws of the various forces should be understood. A significant feature of the present approach is that a positive and unambiguous basis for identifying the wavemaking force is offered and compared with theoretical predictions. This force, according to the definition proposed, is assured a proper compliance with the physical laws which govern the waves generated and the corresponding scaling and interference effects, which are predicted by theory.
The Rates of Change of the Eigenvalues of a Lambda Matrix and their Use in Flutter Investigations
Authors: Woodcock D. L. 
Published: July 2016

Consider a lambda matrix F(ƛ, δ). This may, for example, result from the equation of motion of a dynamical system, δ being a measure of the magnitude of some possible modification to the system or some other variable parameter. Let λ be an eigenvalue and p’ and q the corresponding left hand and right hand eigenvectors. ThenOne wishes to determine the derivatives of ƛ with respect to δ. Expressions for the first two derivatives will be obtained on the assumptions that F is simply degenerate and that ƛ is not a repeated root.
Initial Flow in the Entrance of a Straight Circular Pipe
Authors: Gillis J. , Shimshoni M. 
Published: July 2016

A solution of the problem of the initial flow in the entrance region of a pipe has been given by Atkinson and Goldstein. In this note the authors compute this solution in greater detail, and compare their results with those of Atkinson and Goldstein. The range of the validity of the solution is shown to be smaller than originally thought.Atkinson and Goldstein considered the equations for the steady flow of an incompressible viscous fluid into a straight circular pipe of radius a. The flow is supposed to have axial symmetry, u being the velocity component parallel to the axis x, and v the radial velocity. The, distance from the axis is denoted by r.
A Career in the Aerospace Industry
Authors: Ewins P. D. 
Published: July 2016

As I come to the end of five years’ training as an Aeronautical Engineer, several thoughts come to mind, both about my training up to the present time and the future of the aerospace industry in which I am about to serve.During the past ten years, the aerospace industry has seen many changes, not only in the form of amalgamations and project cancellations, but also in the way it must face the future. More recently it has seen the publication of the Plowden Report with all its implications. Although for many the future paints a gloomy picture, at no time has the thought of leaving the world of aeronautics been farther from my mind than it is now.
A Note on the Improved Displaced Frequency Method Applied to Dynamical Systems Having a Pair of Equal Frequencies
Authors: Simpson A. 
Published: July 2016

In applying the numerical correction method to the case where two natural frequencies of the system under test are equal, it is necessary to ensure that the matrixis diagonal in order to eliminate singularities. (In this equation δA is the displaced mass matrix; is the partitioned matrix containing the two modal columns appropriate to the equal frequencies and β is a transformation matrix (2 x 2), chosen to ensure that δαb is diagonal.)
Ten Economic Lessons from Short-Haul Airline Operations
Authors: Wheatcroft Stephen F. 
Published: July 2016

The 1,179th Main Lecture to be given before the Society–and the first Main Lecture to be given in the new Lecture Theatre–“Ten Economic Lessons from Short-Haul Airline Operations,” was given by Mr. S. F. Wheatcroft, B.Sc.(Econ.), A.F.R.Ae.S., on 15th December 1960. Mr. P. G. Masefield, M.A.(Eng.), F.R.Ae.S., Hon.F.I.A.S., Immediate Past President, presided.Before introducing the Lecturer, Mr. Masefield said ttiat this was an auspicious occasion because this was the first Main Society Lecture to be held in the Lecture Theatre. Although he was sure there was nobody better fitted than Steve Wheatcroft to give this first lecture and no more valuable subject than the economic lessons from short-haul airline operations, Mr. Wheatcroft unfortunately had let the side down by not requiring any of the modern pushbutton equipment which was a feature of the Lecture Theatre.Steve Wheatcroft was known to everybody in air transport, not only in this country but all over the world, where he spent half his time when he was not advising B.E.A. on what not to do. Mr. Wheatcroft obtained his B.Sc. degree with first class honours in economics at the London School of Economics in 1942. After the war, during which he served as a pilot in the Fleet Air Arm, he returned to the London School of Economics, taking a Leverhulme Post Graduate Studentship and studying, in particular, the economics of air transport. He was appointed Economic Adviser to British European Airways in 1946 and subsequently joined the Commercial Department as Manager in charge of Research and Tariffs. In 1953 he left the Corporation to go to Manchester University as a Simon Research Fellow and wrote a book called “The Economics of European Air Transport”. Wheatcroft on “The Economics of European Air Transport” was still a standard and was rapidly becoming a classic work. Since 1954 he had acted as a Consultant and had been retained as Economic Adviser to British European Airways. In 1958 he was commissioned by the Canadian Government to make a study of the desirability and economic consequences of trans-continental competition and his report, “Air Competition in Canada,” was published in June 1958. In 1959 he was appointed Chairman of a Committee set up by the Government of India to investigate the cost structure of the Indian Airline Corporation. More recently he had been a member of the Tymms Committee to the West Indian Government to advise on civil air policy in the West Indies, and now, he was about to go to Nigeria to tell them how to do it.
Flutter of an Aircraft Controlled by an Automatic Navigation System
Authors: Parks P. C. 
Published: July 2016

Automatic navigation systems for aircraft often use gyroscopes to measure the changes in the direction of motion of the aircraft they are controlling. These measurements are fed back to the mechanisms moving the control surfaces of the aircraft.Such a system is usually designed, in the first instance, assuming the aircraft structure to be rigid and such that the system is then stable.Now suppose the aircraft structure, considered elastic, is disturbed in flight by, say, a gust. Normal modes of vibration of the structure will be excited, the resulting oscillations will be detected by the gyroscope and fed as error signals to the control surface actuators. If the actuators are capable of following these error signals, the control surfaces will also oscillate, exciting the structure further and so completing the cycle. This cycle may be unstable.
Transactional processes in the development of adult personality disorder symptoms
Authors: Carlson Elizabeth A. , Ruiz Sarah K. 
Published: July 2016

AbstractThe development of adult personality disorder symptoms, including transactional processes of relationship representational and behavioral experience from infancy to early adolescence, was examined using longitudinal data from a risk sample (N= 162). Significant preliminary correlations were found between early caregiving experience and adult personality disorder symptoms and between representational and behavioral indices across time and adult symptomatology. Significant correlations were also found among diverse representational assessments (e.g., interview, drawing, and projective narrative) and between concurrent representational and observational measures of relationship functioning. Path models were analyzed to investigate the combined relations of caregiving experience in infancy; relationship representation and experience in early childhood, middle childhood, and early adolescence; and personality disorder symptoms in adulthood. The hypothesized model representing interactive contributions of representational and behavioral experience represented the data significantly better than competing models representing noninteractive contributions. Representational and behavioral indicators mediated the link between early caregiving quality and personality disorder symptoms. The findings extend previous studies of normative development and support an organizational developmental view that early relationship experiences contribute to socioemotional maladaptation as well as adaptation through the progressive transaction of mutually informing expectations and experience.
Transactional cascades of destructive interparental conflict, children's emotional insecurity, and psychological problems across childhood and adolescence
Authors: Davies Patrick T. , Martin Meredith J. , Coe Jesse L. , Cummings E. Mark 
Published: July 2016

AbstractThis study examined the transactional interplay among dimensions of destructive interparental conflict (i.e., hostility and dysphoria), children's emotional insecurity, and their psychological problems from middle childhood and adolescence. Participants were 232 families, with the first of five measurement occasions occurring when children were in first grade (M age = 7 years). Cross-lagged, autoregressive models were conducted with a multiple-method, multiple-informant measurement approach to identify developmental cascades of interparental and child cascades. Results indicated that emotional insecurity was a particularly powerful mediator of prospective associations between interparental conflict (i.e., dysphoria and hostility) and child adjustment during adolescence rather than childhood. In reflecting bidirectionality in relationships between interparental and child functioning, children's psychological problems predicted increases in interparental dysphoria during childhood and adolescence. Although emotional insecurity was not identified as a proximal predictor of interparental difficulties, an indirect cascade was identified whereby insecurity in early adolescence was associated with increases in teen psychological problems, which in turn predicted greater interparental dysphoria over time. Results are interpreted in the context of how they advance transactional formulation of emotional security theory and its resulting translational implications for clinical initiatives.
Transactional relations between caregiving stress, executive functioning, and problem behavior from early childhood to early adolescence
Authors: Lagasse Linda L. , Conradt Elisabeth , Karalunas Sarah L. , Dansereau Lynne M. , Butner Jonathan E. , Shankaran Seetha , Bada Henrietta , Bauer Charles R. , Whitaker Toni M. , Lester Barry M. 
Published: July 2016

AbstractDevelopmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (a) how these transactions originate, (b) whether they persist over time to contribute to the development of problem behavior and (c) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth to age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior.
Long-term effects of the Family Bereavement Program on spousally bereaved parents: Grief, mental health problems, alcohol problems, and coping efficacy
Authors: Sandler Irwin , Tein Jenn-Yun , Cham Heining , Wolchik Sharlene , Ayers Tim 
Published: July 2016

AbstractThis study reports on the findings from a 6-year follow-up of a randomized trial of the Family Bereavement Program (FBP) on the outcomes for spousally bereaved parents. Spousally bereaved parents (N= 131) participated in the trial in which they were randomly assigned to receive the FBP (N= 72) or literature control (N= 59). Parents were assessed at four time points: pretest, posttest, and 11-month and 6-year follow-up. They reported on mental health problems, grief, and parenting at all four time periods. At the 6-year follow-up, parents reported on additional measures of persistent complex bereavement disorder, alcohol abuse problems, and coping efficacy. Bereaved parents in the FBP as compared to those in the literature control had lower levels of symptoms of depression, general psychiatric distress, prolonged grief, and alcohol problems, and higher coping efficacy (for mothers) at the 6-year follow-up. Multiple characteristics of the parent (e.g., gender, age, and baseline mental health problems) and of the spousal death (e.g., cause of death) were tested as moderators of program effects on each outcome, but only 3 of 45 tests of moderation were significant. Latent growth modeling found that the effects of the FBP on depression, psychiatric distress, and grief occurred immediately following program participation and were maintained over 6 years. Mediation analysis found that improvement in positive parenting partially mediated program effects to reduce depression and psychiatric distress, but had an indirect effect to higher levels of grief at the 6-year follow-up. Mediation analysis also found that improved parenting at the 6-year follow-up was partially mediated by program effects to reduce depression and that program effects to increase coping efficacy at the 6-year follow-up was partially mediated through reduced depression and grief and improved parenting. FBP reduced mental health problems, prolonged grief, and alcohol abuse, and increased coping efficacy of spousally bereaved parents 6 years later. Mediation pathways for program effects differed across outcomes at the 6-year follow-up.
The bidirectional pathways between internalizing and externalizing problems and academic performance from 6 to 18 years
Authors: Van der Ende Jan , Verhulst Frank C. , Tiemeier Henning 
Published: July 2016

AbstractInternalizing and externalizing problems are associated with poor academic performance, both concurrently and longitudinally. Important questions are whether problems precede academic performance or vice versa, whether both internalizing and externalizing are associated with academic problems when simultaneously tested, and whether associations and their direction depend on the informant providing information. These questions were addressed in a sample of 816 children who were assessed four times. The children were 6–10 years at baseline and 14–18 years at the last assessment. Parent-reported internalizing and externalizing problems and teacher-reported academic performance were tested in cross-lagged models to examine bidirectional paths between these constructs. These models were compared with cross-lagged models testing paths between teacher-reported internalizing and externalizing problems and parent-reported academic performance. Both final models revealed similar pathways from mostly externalizing problems to academic performance. No paths emerged from internalizing problems to academic performance. Moreover, paths from academic performance to internalizing and externalizing problems were only found when teachers reported on children's problems and not for parent-reported problems. Additional model tests revealed that paths were observed in both childhood and adolescence. Externalizing problems place children at increased risk of poor academic performance and should therefore be the target for interventions.