3,948 research outputs found
An analytical design procedure for the determination of effective leading edge extensions on thick delta wings
An analytical design procedure for leading edge extensions (LEE) was developed for thick delta wings. This LEE device is designed to be mounted to a wing along the pseudo-stagnation stream surface associated with the attached flow design lift coefficient of greater than zero. The intended purpose of this device is to improve the aerodynamic performance of high subsonic and low supersonic aircraft at incidences above that of attached flow design lift coefficient, by using a vortex system emanating along the leading edges of the device. The low pressure associated with these vortices would act on the LEE upper surface and the forward facing area at the wing leading edges, providing an additional lift and effective leading edge thrust recovery. The first application of this technique was to a thick, round edged, twisted and cambered wing of approximately triangular planform having a sweep of 58 deg and aspect ratio of 2.30. The panel aerodynamics and vortex lattice method with suction analogy computer codes were employed to determine the pseudo-stagnation stream surface and an optimized LEE planform shape
On-line measurement of heat of combustion
An experimental method for an on-line measurement of heat of combustion of a gaseous hydrocarbon fuel mixture of unknown composition is developed. It involves combustion of a test gas with a known quantity of air to achieve a predetermined oxygen concentration level in the combustion products. This is accomplished by a feedback controller which maintains the gas volumetric flow rate at a level consistent with the desired oxygen concentration in the products. The heat of combustion is determined from a known correlation with the gas volumetric flow rate. An on-line microcomputer accesses the gas volumetric flow data, and displays the heat of combustion values at desired time intervals
Transverse Momentum Distribution and Elliptic Flow of Charged Hadrons in + collisions at GeV using HYDJET++
Recent experimental observations of the charged hadron properties in
collisions at GeV contradict many of the theoretical models of particle
production including two-component Monte Carlo Glauber model. The experimental
results show a small correlation between the charged hadron properties and the
initial geometrical configurations (e.g. body-body, tip-tip etc.) of
collisions. In this article, we have modified the Monte Carlo HYDJET++ model to
study the charged hadron production in collisions at GeV
center-of-mass energy in tip-tip and body-body initial configurations. We have
modified the hard as well as soft production processes to make this model
suitable for collisions. We have calculated the pseudorapidity
distribution, transverse momentum distribution and elliptic flow distribution
of charged hadrons with different control parameters in various geometrical
configurations possible for collision. We find that HYDJET++ model
supports a small correlation between the various properties of charged hadrons
and the initial geometrical configurations of collision. Further, the
results obtained in modified HYDJET++ model regarding and
elliptic flow () suitably matches with the experimental data of
collisions in minimum bias configuration.Comment: 29 pages, 25 figures. Accepted for Publication in EPJ
Preventive and Protective Solution for Corrosion in Concrete through Chemistry
Damage caused by corrosion of concrete structure has been recognized as one of the major problem affecting service life of structure. But corrosion cannot be stopped compl-etely.It can be reduced if certain practices to combat corrosion are applied. Permeability is the gateway of corrosion. Hence corrosion - permeability interaction has been presented in this paper. Water proofing has been
suggested as preventive solution for concrete structure
exposed to corrosive environment . Structures are damaged due to corrosion in concrete.Suitable and effective
repair system is unavoidable protective solution for corrosion affected concrete structure. In the present paper the authors have made an attempt to present prev-entive and protective solution of corrosion in concrete through chemistry. Repair material, its criteria , various techniques and methodology has also been discussed. The
approach is also illustrated by presenting two case studies
Berry's phase for coherent states of Landau levels
The Berry phases for coherent states and squeezed coherent states of Landau
levels are calculated. Coherent states of Landau levels are interpreted as a
result of a magnetic flux moved adiabatically from infinity to a finite place
on the plane. The Abelian Berry phase for coherent states of Landau levels is
an analog of the Aharonov- Bohm effect. Moreover, the non-Abelian Berry phase
is calculated for the adiabatic evolution of the magnetic field B.Comment: 4 pages, 1 figur
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