1,866 research outputs found
Pressure distribution on wing ribs of the VE-7 and TS airplanes in flight
This paper is the first of a series of notes, each of which presents the complete results of pressure distribution tests made by the National Advisory Committee for Aeronautics, on single-wing ribs of the VE-7 and TS airplanes for a particular condition of flight. The level flight results are presented here in the form of curves and show the comparison between the pressure distribution over a representative thin wing, R.A.F.-15, and a moderately thick wing, U.S.A.-27, throughout the range of angle of attack
Mass distribution and performance of free flight models
This note deals with the mass distribution and performance of free flight models. An airplane model which is to be used in free flight tests must be balanced dynamically as well as statically, e.g., it must not only have a given weight and the proper center of gravity but also a given ellipsoid of inertia. Equations which relate the motions of an airplane and its model are given. Neglecting scale effect, these equations may be used to predict the performance of an airplane, under the action of gravity alone, from data obtained in making dropping tests of a correctly balanced model
The Pressure Distribution over the Horizontal and Vertical Tail Surfaces of the F6C-4 Pursuit Airplane in Violent Maneuvers
This investigation of the pressure distribution on the tail surfaces of a pursuit airplane in violent maneuvers was conducted for the purpose of determining the maximum loads likely to be encountered on these surfaces in flight. The information is a part of that needed for a revision of existing loading specifications to bring these into closer agreement with the actual flight conditions. A standard F6C-4 airplane was used and the pressure distribution over the right horizontal and complete vertical tail surfaces was recorded throughout violent maneuvers. The results show that the existing loading specifications do not conform satisfactorily to the loadings existent in critical conditions, and in some cases were exceeded by the loads obtained. An acceleration of 10.5 G. Was recorded in one maneuver in which the pilot suffered severely; it is therefore indicated that the limits of the physical resistance of the pilot to violent maneuvers are being approached. Navy specifications for the structural design of tail surfaces are included as an appendix. (author
Pressure distribution on wing ribs of the VE-7 and TS airplanes in flight Part II : pull-ups
This paper is the second of a series of notes, each of which presents the complete results of pressure distribution tests made at Langley Field by the National Advisory Committee for Aeronautics, on wing and tail ribs of the VE-7 and TS airplanes for a particular maneuver of flight. The results for pull-ups are presented in the form of curves which show the variation of pressure distribution, total loads, normal acceleration and center of pressure with respect to time
Holomorphic Parafermions in the Potts model and SLE
We analyse parafermionic operators in the Q-state Potts model from three
different perspectives. First, we explicitly construct lattice holomorphic
observables in the Fortuin-Kasteleyn representation, and point out some special
simplifying features of the particular case Q=2 (Ising model). In particular,
away from criticality, we find a lattice generalisation of the massive Majorana
fermion equation. We also compare the parafermionic scaling dimensions with
known results from CFT and Coulomb gas methods in the continuum. Finally, we
show that expectation values of these parafermions correspond to local
observables of the SLE process which is conjectured to describe the scaling
limit of the Q-state Potts model.Comment: 18 pages. v2: references to related work clarified. v3: minor
corrections, version accepted for publication in JSTA
Airfoil section characteristics as applied to the prediction of air forces and their distribution on wings
The results of previous reports dealing with airfoil section characteristics and span load distribution data are coordinated into a method for determining the air forces and their distribution on airplane wings. Formulas are given from which the resultant force distribution may be combined to find the wing aerodynamic center and pitching moment. The force distribution may also be resolved to determine the distribution of chord and beam components. The forces are resolved in such a manner that it is unnecessary to take the induced drag into account. An illustration of the method is given for a monoplane and a biplane for the conditions of steady flight and a sharp-edge gust. The force determination is completed by outlining a procedure for finding the distribution of load along the chord of airfoil sections
The Effect of Substructure on Mass Estimates of Galaxies
Large galaxies are thought to form hierarchically, from the accretion and
disruption of many smaller galaxies. Such a scenario should naturally lead to
galactic phase-space distributions containing some degree of substructure. We
examine the errors in mass estimates of galaxies and their dark halos made
using the projected phase-space distribution of a tracer population (such as a
globular cluster system or planetary nebulae) due to falsely assuming that the
tracers are distributed randomly. The level of this uncertainty is assessed by
applying a standard mass estimator to samples drawn from 11 random realizations
of galaxy halos containing levels of substructure consistent with current
models of structure formation. We find that substructure will distort our mass
estimates by up to ~20% - a negligible error compared to statistical and
measurement errors in current derivations of masses for our own and other
galaxies. However, this represents a fundamental limit to the accuracy of any
future mass estimates made under the assumption that the tracer population is
distributed randomly, regardless of the size of the sample or the accuracy of
the measurements.Comment: 9 pages, 8 figures, Astrophysical Journal, in pres
The Lake Baikal neutrino experiment: selected results
We review the present status of the lake Baikal Neutrino Experiment and
present selected physical results gained with the consequetive stages of the
stepwise increasing detector: from NT-36 to NT-96. Results cover atmospheric
muons, neutrino events, very high energy neutrinos, search for neutrino events
from WIMP annihilation, search for magnetic monopoles and environmental
studies. We also describe an air Cherenkov array developed for the study of
angular resolution of NT-200.Comment: 25 pages, 12 figures. To appear in the Procrrdings of International
Conference on Non-Accelerator New Physics, June 28 - July 3, 1999, Dubna,
Russi
Fluxes of atmospheric muons underwater depending on the small-x gluon density
The prompt muon contribution to the deep-sea atmospheric muon flux can serve
as a tool for probing into the small-x feature of the gluon density inside of a
nucleon, if the muon energy threshold could be lifted to 100 TeV. The prompt
muon flux underwater is calculated taking into consideration predictions of
recent charm production models in which the small-x behaviour of the gluon
distribution is probed. We discuss the possibility of distinguishing the PQCD
models of the charm production differing in the small-x exponent of the gluon
distribution, in measurements of the muon flux at energies 10-100 TeV with
neutrino telescopes.Comment: 9 pages, 4 eps figures, uses iopart.st
BAIKAL experiment: status report
We review the present status of the Baikal Neutrino Project and present the
results obtained with the deep underwater neutrino telescope NT-200.Comment: 4 pages, 3 figures. Presented at TAUP 2001 (7th international
workshop on Topics in Astroparticle and Underground Physics), Sep. 2001,
Laboratori Nazionali del Gran Sasso, Assergi, Ital
- …