scholarly journals An analysis of the accelerations of a projectile in a gun tube by direct measurements and telemetry of the data

2018 ◽  
Vol 19 (4) ◽  
pp. 406 ◽  
Author(s):  
Mathilda Liennard ◽  
Ophélie Chevalier ◽  
André Langlet ◽  
Yann Guilmard ◽  
Marcel Mansion
Keyword(s):  
Numerical Simulation ◽  
Laser Light ◽  
Light Emission ◽  
Internal Ballistic ◽  
Direct Measurements ◽  
Tube Geometry

In this study, transverse and longitudinal accelerations of a full caliber-shell shot by a medium-caliber gun were measured directly during the internal ballistic (IB) phase. The data were transmitted outside the tube by modulation of LASER light emission and recoded into acceleration values. The results were analyzed through the numerical simulation of the response of the tube traversed by the projectile and with the internal-ballistic data providing the longitudinal projectile acceleration. The analysis reveals that the in-bore projectile movements are both influenced by the tube geometry (curvature and straightness defects) and by the tube response during the internal ballistic phase. However, in this work, the tube response appeared to be of greater influence on the projectile dynamics than the tube initial static geometry. Results provide basis for further calibration studies.

Study of the Influence of the Erosion and Wear on Artillery Internal Ballistic Performance

2013 ◽  
Vol 475-476 ◽  
pp. 1499-1502
Author(s):  
Wen Wen Yu ◽  
Hai Tao Sun ◽  
Li Qing Fang ◽  
Zi Long Ma
Keyword(s):  
Numerical Simulation ◽  
Ballistic Performance ◽  
Internal Ballistic ◽  
Ballistic Model

In order to investigate the influence of the erosion and wear on artillery ballistic performance, artillery ballistic model was founded, and graphic integration was used for providing the calculation of internal ballistic parameters. Base on this method, the influence of the erosion and wear on artillery internal ballistic performance was analyzed with the help of numerical simulation.

scholarly journals Response of laser-localized structures to external perturbations in coupled semiconductor microcavities

2014 ◽  
Vol 372 (2027) ◽  
pp. 20140004 ◽  
Author(s):  
M. Turconi ◽  
M. Giudici ◽  
S. Barland
Keyword(s):  
Semiconductor Lasers ◽  
Laser Light ◽  
Light Emission ◽  
Localized States ◽  
Time Resolved ◽  
External Perturbations ◽  
Localized Structures ◽  
Coupled Lasers ◽  
The Stability

Laser-localized structures have been observed in several experiments based on broad-area semiconductor lasers. They appear as bounded regions of laser light emission which can exist independently of each other and are expected to be commuted via external optical perturbations. In this work, we perform a statistical analysis of time-resolved commutation experiments in a system of coupled lasers and show the role of wavelength, polarization and pulse energy in the switching process. Furthermore, we also analyse the response of the system outside of the stability region of laser-localized states in search of an excitable response. We observe not only a threshold separating two types of responses, but also a strong variability in the system's trajectory when returning to the initial stable fixed point.

SRM Internal Ballistic Numerical Simulation by SPINBALL Model

2009 ◽  
Author(s):  
Enrico Cavallini ◽  
Bernardo Favini ◽  
Maurizio Di Giacinto ◽  
Ferruccio Serraglia
Keyword(s):  
Numerical Simulation ◽  
Internal Ballistic

Identification of Boundary Forces in Beams From Measured Displacements

2006 ◽  
Vol 128 (6) ◽  
pp. 757-771 ◽  
Author(s):  
S. Chesne ◽  
C. Pezerat ◽  
J. L. Guyader
Keyword(s):  
Numerical Simulation ◽  
Shear Force ◽  
Good Accuracy ◽  
Bending Moment ◽  
Weak Form ◽  
Equation Of Motion ◽  
Test Functions ◽  
Direct Measurements ◽  
Simulation Results ◽  
Measured Displacement

This paper deals with shear force and bending moment identification in a beam from measured displacement. The proposed approach, using the weak form of the equation of motion, is based on the extraction of shear force or bending moment from integral equation and choice of test functions, associated to each boundary quantity of interest. After the theorical description, numerical simulation results are shown in order to clarify limits of the method and to stress its self-regularization. Two experimentations are described, showing very good accuracy of shear force and bending moment reconstruction in comparison with direct measurements.

scholarly journals Spatial spectrum of coherence signal for a defocused object images in digital holographic microscopy with partially spatially coherent illumination

2018 ◽  
Vol 42 (3) ◽  
pp. 414-423
Author(s):  
D. M. Klychkova ◽  
V. P. Ryabukho
Keyword(s):  
Numerical Simulation ◽  
High Frequency ◽  
Laser Light ◽  
Spatial Spectrum ◽  
Theoretical Description ◽  
Digital Holographic Microscopy ◽  
Object Image ◽  
Holographic Microscopy ◽  
Coherent Illumination ◽  
Good Agreement

We study the effect of a decrease in the magnitude of the coherence signal in high-frequency spatial spectrum for a defocused object image in transmission digital holographic microscopy with quasimonochromatic partially spatially coherent illumination. A theoretical description and results of the numerical simulation of the effect for a point scattering object are presented. The effect is experimentally studied by illuminating layered quasi-point scatterers with partially spatially coherent laser light obtained using a moving scatterer. The comparison of the experimental and theorybased numerical results shows them to be in good agreement.

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