The initial velocity of advance of the interphase boundary

2016 ◽  
pp. 190-216
Keyword(s):  
Interphase Boundary ◽  
Initial Velocity

APPLICATION OF THE METHOD SPRINGY DEFORMATIONS OF BARREL DURING SHOT FOR DETERMINING THE INITIAL VELOCITY OF THE SHELL (MINE)

2019 ◽  
Vol 1 (12) ◽  
pp. 75-80
Author(s):  
Ye. Didenko ◽  
O. Stepanenko
Keyword(s):  
Strain Gauge ◽  
Initial Velocity ◽  
Radial Direction ◽  
Fire Control ◽  
Automatic Control Systems ◽  
Measurement Results ◽  
Initial Resistance ◽  
The Moment ◽  
The Many ◽  
Effective Use

One of the indicators of the effective use of artillery is the accuracy of the fire impact on the objects of enemy. The accuracy of the artillery is achieved by completing the implementation of all measures for the preparation of shooting and fire control. Main measures of ballistic preparation are to determine and take into account the summary deviation of the initial velocity. The existing procedure for determining the summary deviation of the initial velocity for the check (main) cannon of battery leads to accumulation of ballistic preparation errors. The supply of artillery units with means of determining the initial speed of the projectile is insufficient. Among the many known methods for measuring the initial velocity, not enough attention was paid to the methods of analyzing the processes that occur during a shot in the "charge-shell-barrel" system. Under the action of the pressure of the powder gases in the barrel channel and the forces of the interaction of the projectile with the barrel there are springy deformations in the radial direction. To measure springy deformations it is advisable to use strain gauge sensors. Monitoring of deformation in a radial direction by time can be used to determine the moment of passing a projectile past the strain gauge mounted on the outer surface of the barrel. In the case of springy deformations, the initial resistance of the sensor varies in proportion to its value. The speed of the shell (mine) in the barrel can be determined by time between pulses of signals obtained from strain gauges located at a known distance from each other. The simplicity of the proposed method for measuring the initial velocity of an artillery shell provides an opportunity for equipping each cannon (mortar) with autonomous means for measuring the initial velocity. With the simultaneous puting into action of automatic control systems can be automatically taking into account the measurement results. This will change the existing procedure for determining the total deviation of the initial velocity and improve the accuracy, timeliness and suddenness of the opening of artillery fire, which are components of its efficiency.

Numerical Modeling of Evolution of Boundary Between Incompressible Gas and Liquid in Two-Dimensional Region

2006 ◽  
Vol 4 ◽  
pp. 224-236
Author(s):  
A.S. Topolnikov
Keyword(s):  
Numerical Modeling ◽  
Interphase Boundary ◽  
Incompressible Liquid ◽  
Stokes Equations ◽  
Numerical Code ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Incompressible Media ◽  
Good Agreement

The paper is devoted to numerical modeling of Navier–Stokes equations for incompressible media in the case, when there exist gas and liquid inside the rectangular calculation region, which are separated by interphase boundary. The set of equations for incompressible liquid accounting for viscous, gravitational and surface (capillary) forces is solved by finite-difference scheme on the spaced grid, for description of interphase boundary the ideology of Level Set Method is used. By developed numerical code the set of hydrodynamic problems is solved, which describe the motion of two-phase incompressible media with interphase boundary. As a result of numerical simulation the solutions are obtained, which are in good agreement with existing analytical and experimental solutions.

scholarly journals Full-Waveform Inversion for Imaging Faulted Structures: A Case Study from the Japan Trench Forearc Slope

2021 ◽  
Author(s):  
Ehsan Jamali Hondori ◽  
Chen Guo ◽  
Hitoshi Mikada ◽  
Jin-Oh Park
Keyword(s):  
Seismic Data ◽  
Initial Velocity ◽  
Waveform Inversion ◽  
Velocity Model ◽  
Control Measures ◽  
Japan Trench ◽  
Full Waveform Inversion ◽  
Full Waveform ◽  
Time Migration ◽  
Shallow Sediments

AbstractFull-waveform inversion (FWI) of limited-offset marine seismic data is a challenging task due to the lack of refracted energy and diving waves from the shallow sediments, which are fundamentally required to update the long-wavelength background velocity model in a tomographic fashion. When these events are absent, a reliable initial velocity model is necessary to ensure that the observed and simulated waveforms kinematically fit within an error of less than half a wavelength to protect the FWI iterative local optimization scheme from cycle skipping. We use a migration-based velocity analysis (MVA) method, including a combination of the layer-stripping approach and iterations of Kirchhoff prestack depth migration (KPSDM), to build an accurate initial velocity model for the FWI application on 2D seismic data with a maximum offset of 5.8 km. The data are acquired in the Japan Trench subduction zone, and we focus on the area where the shallow sediments overlying a highly reflective basement on top of the Cretaceous erosional unconformity are severely faulted and deformed. Despite the limited offsets available in the seismic data, our carefully designed workflow for data preconditioning, initial model building, and waveform inversion provides a velocity model that could improve the depth images down to almost 3.5 km. We present several quality control measures to assess the reliability of the resulting FWI model, including ray path illuminations, sensitivity kernels, reverse time migration (RTM) images, and KPSDM common image gathers. A direct comparison between the FWI and MVA velocity profiles reveals a sharp boundary at the Cretaceous basement interface, a feature that could not be observed in the MVA velocity model. The normal faults caused by the basal erosion of the upper plate in the study area reach the seafloor with evident subsidence of the shallow strata, implying that the faults are active.

scholarly journals Initial Velocity and Equilibrium Kinetics of Myokinase

1968 ◽  
Vol 243 (14) ◽  
pp. 3963-3972
Author(s):  
D G Rhoads ◽  
J M Lowenstein
Keyword(s):  
Initial Velocity ◽  
Kinetics Of

Structural relaxation by interphase boundary migration in pure tin

1983 ◽  
Vol 2 (11) ◽  
pp. 653-656 ◽  
Author(s):  
R. Kamel ◽  
S. A. Mahmoud ◽  
Z. Farid ◽  
N. El Naquib
Keyword(s):  
Interphase Boundary ◽  
Structural Relaxation ◽  
Boundary Migration

scholarly journals Study on the initial velocity distribution of exhaled air from coughing and speaking

Chemosphere ◽  
2012 ◽  
Vol 87 (11) ◽  
pp. 1260-1264 ◽  
Author(s):  
Soon-Bark Kwon ◽  
Jaehyung Park ◽  
Jaeyoun Jang ◽  
Youngmin Cho ◽  
Duck-Shin Park ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Initial Velocity ◽  
Initial Velocity Distribution ◽  
Exhaled Air

scholarly journals Changes in the charge of an α-Particle passing through matter

1923 ◽  
Vol 102 (717) ◽  
pp. 496-506 ◽  
Keyword(s):  
Initial Velocity ◽  
Rapid Decrease ◽  
Number Of Particles

It is remarkable that investigations on the velocity of α -particles have hitherto failed to detect with certainty particles of velocity less than about 8 x 10 8 cm. per second (0.4V 0 , where V 0 is the initial velocity of α -particles from RaC). Geiger believed he had found a-particles with velocities as low as 0.3V 0 . However, later work of Marsden and Taylor showed that when the velocity of an α -ray beam had fallen to about 0.45V 0 , any further increase of absorption caused a rapid decrease in the number of particles; the number fell to zero when the velocity had decreased to about 0.4V 0 . Thus the minimum observed energy was that which would be acquired by the α -particle in falling through about 600,000 volts. It is surprising that particles with such enormous energy should vanish, leaving no trace. Positive rays of much less energy have of course been detected in several ways.

GLOBAL EXISTENCE TO THE NAVIER–STOKES EQUATIONS THROUGH A SELF-SIMILAR-LIKE UPPER SOLUTION

2012 ◽  
Vol 14 (05) ◽  
pp. 1250031
Author(s):  
GUY BERNARD
Keyword(s):  
Global Existence ◽  
Heat Equation ◽  
Initial Velocity ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Dimensional Euclidean Space ◽  
Time Interval ◽  
Navier Stokes Equations ◽  
Upper Solution ◽  
Self Similar

A global existence result is presented for the Navier–Stokes equations filling out all of three-dimensional Euclidean space ℝ3. The initial velocity is required to have a bell-like form. The method of proof is based on symmetry transformations of the Navier–Stokes equations and a specific upper solution to the heat equation in ℝ3× [0, 1]. This upper solution has a self-similar-like form and models the diffusion process of the heat equation. By a symmetry transformation, the problem is transformed into an equivalent one having a very small initial velocity. Using the upper solution, the equivalent problem is then solved in the time interval [0, 1]. This local solution is then extended to the time interval [0, ∞) by an iterative process. At each step, the problem is extended further in time in an interval of time whose length is greater than one, thus producing the global solution. Each extension is transformed, by an appropriate change of variables, into the first local problem in the time interval [0, 1]. These transformations exploit the diffusive and self-similar-like nature of the upper solution.

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