Forms of possible delamination of the liner in a metal composite high pressure vessel

2019 ◽  
Author(s):  
N.V. Bykov
Keyword(s):  
External Source ◽  
Initial Distribution ◽  
Initial Moment ◽  
Metal Composite ◽  
Wave Processes ◽  
One Dimensional ◽  
External Forces ◽  
Gas Guns ◽  
Research Show ◽  
Gas Dynamic Equations

The purpose of the paper was to study the effect of induced gas perturbations in the reservoir on the ballistic characteristics of single-stage gas guns. Two ways of waves generation at the initial moment are considered: by means of a non-uniform initial distribution of gas parameters and by creating a shock wave propagating from the bottom of the reservoir by external forces. The study is based on the numerical solution of one-dimensional gas-dynamic equations on a moving grid. Findings of research show that for relatively large (compared to the accelerating gas mass) mass of the projectiles, the wave processes induced by inhomogeneous filling lead to an increase in the muzzle velocity 1.4 times, and the shock waves generation by an external source — 1.8 times.

scholarly journals A new class of discontinuous solar wind solutions

2020 ◽  
Vol 496 (2) ◽  
pp. 1023-1034
Author(s):  
Bidzina M Shergelashvili ◽  
Velentin N Melnik ◽  
Grigol Dididze ◽  
Horst Fichtner ◽  
Günter Brenn ◽  
...  
Keyword(s):  
Solar Wind ◽  
External Source ◽  
Analytic Solutions ◽  
Governing Equations ◽  
Discontinuous Solutions ◽  
One Dimensional ◽  
Heating Source ◽  
New Class ◽  
Localized Heating ◽  
Physical Quantities

ABSTRACT A new class of one-dimensional solar wind models is developed within the general polytropic, single-fluid hydrodynamic framework. The particular case of quasi-adiabatic radial expansion with a localized heating source is considered. We consider analytical solutions with continuous Mach number over the entire radial domain while allowing for jumps in the flow velocity, density, and temperature, provided that there exists an external source of energy in the vicinity of the critical point that supports such jumps in physical quantities. This is substantially distinct from both the standard Parker solar wind model and the original nozzle solutions, where such discontinuous solutions are not permissible. We obtain novel sample analytic solutions of the governing equations corresponding to both slow and fast winds.

IV.—Expansion of a Finite One-dimensional Gas Cloud into a Vacuum

1953 ◽  
Vol 64 (1) ◽  
pp. 57-70
Author(s):  
A. G. Mackie
Keyword(s):  
Density Distribution ◽  
Analytical Solutions ◽  
Initial Density ◽  
Initial Distribution ◽  
One Dimensional ◽  
Gas Streams ◽  
Subsequent Motion ◽  
Gas Cloud ◽  
Initial Density Distribution ◽  
Stationary Period

SynopsisAn investigation is made of the motion of a one-dimensional finite gas cloud which is initially at rest and is allowed to expand into a vacuum in both directions. The density of the gas at rest is assumed to rise steadily and continuously from zero at the boundaries to a maximum in the interior of the cloud.If the subsequent motion is continuous, it is completely specified by analytical solutions in seven different regions of the x-t plane joined together along characteristics. The motion of one of the boundaries is discussed, and conditions found for it to have (i) an initial stationary period or (ii) a final constant velocity of advance into the vacuum. The gas streams in both directions from a dividing point at zero velocity. This point ultimately tends to the mid-point of the initial distribution.The possible breakdown of the continuity of the motion is discussed, and a condition on the initial density distribution found for shock-free flow to be maintained.

Revisiting V-3 Canon for the Application of Single Stage Gas Gun

2017 ◽  
Author(s):  
Arun Tom Mathew ◽  
Tirumala Rao Koka ◽  
Murali Krishnan Payangapadan
Keyword(s):  
Design Of Experiments ◽  
Numerical Simulations ◽  
Response Surface ◽  
Three Dimensional ◽  
Optimal Location ◽  
Single Stage ◽  
One Dimensional ◽  
Alternative Design ◽  
Gas Gun ◽  
Gas Guns

Single stage gas guns are typically used for accelerating the projectiles in bird and hail impact tests of aerospace components and engines. In this paper an alternative design for single stage gas gun is studied, which is derived from V3 canon. Three dimensional numerical simulations is carried out for the optimal secondary connection angle with the main barrel. A one dimensional code is developed for the V3 canon based design. Design of experiments conducted to find the response surface for the optimal location of the secondary connection, volume and pressure of the secondary tank.

One-dimensional wave processes in a magneto-elastic medium

1996 ◽  
Vol 79 (6) ◽  
pp. 1441-1445
Author(s):  
R. I. Mokrik ◽  
Yu. A. Pyr'ev
Keyword(s):  
Elastic Medium ◽  
Wave Processes ◽  
One Dimensional ◽  
Dimensional Wave

Paper 21: Partly Grooved, Externally Pressurized Bearings

1965 ◽  
Vol 180 (11) ◽  
pp. 123-132
Author(s):  
G. G. Hirs
Keyword(s):  
Fluid Flow ◽  
Load Capacity ◽  
External Source ◽  
Fluid Film ◽  
Flow Through ◽  
External Forces

In externally pressurized bearings, forces can be transmitted by means of a fluid film interposed between the two bearing surfaces by an external source. In the conventional types, the equilibrium of external forces and fluid film forces becomes stable by making the fluid flow through external restrictions before entering the clearance space. In the new types, external restrictions are superfluous. Stability and load capacity are ensured by directing the flow in the clearance space, by means of recurrent grooves on one of the two bearing surfaces, towards a zone where both surfaces are plain.

scholarly journals An electron wave packet in the relativistic strophotron FEL

2021 ◽  
Vol 19 (1) ◽  
pp. 016001
Author(s):  
K B Oganesyan ◽  
M Hnatic ◽  
P Kopchancky
Keyword(s):  
Electron Beam ◽  
Wave Packet ◽  
Initial Distribution ◽  
Quantum Mechanical ◽  
Initial Moment ◽  
Electron Wave ◽  
Electron Wave Packet ◽  
Vibrational Levels ◽  
Mechanical Approach ◽  
Quantum Mechanical Approach

Abstract The theory of free electron lasers (FELs) is well developed both in quantum mechanical and classical approaches. In strophotron FEL, in classical approach, resonance frequency and the gain are strongly dependent on initial parameters of electron beam. In the quantum mechanical approach considered by Zaretsky and Nersesov (1983 JETP 57 518), there is no such dependence. The correspondence between the quantum mechanical and classical approaches in a relativistic strophotron FEL is discussed. We study the initial distribution of electrons over vibrational levels determined by the expansion coefficients in relativistic strophotron FEL. It is shown, (presenting electron wave function in the form of Gaussian wave packet), that the number of the vibrational level most efficiently populated at the initial moment of time can be expressed in terms of the initial parameters of the electron beam.

scholarly journals Stability of equilibrium in a one-dimensional hydrostatic model of the dry atmosphere

2020 ◽  
Vol 4 ◽  
pp. 104-120
Author(s):  
S.M. Semenov ◽  
◽  
◽  
Keyword(s):  
Temperature Distribution ◽  
Negative Temperature ◽  
Initial Distribution ◽  
Ideal Gas ◽  
Underlying Surface ◽  
Wave Radiation ◽  
Radiation Balance ◽  
One Dimensional ◽  
Atmospheric Column ◽  
Hydrostatic Model

Experts in the field of mathematical modeling of the climate system have different views about which class of models should be employed to analyze and predict climate for time scales corresponding to climatic processes. In this paper, we investigate the properties of a model constructed using the hydrostatic hypothesis. A one-dimensional (horizontally homogeneous) hydrostatic model of a dry atmosphere is considered. Air is considered an ideal gas. The source of heat is the external short-wave radiation flux entering the upper boundary of the atmosphere. This energy is partly absorbed by the atmospheric layers and the underlying surface, partly returned to space. The atmospheric layers and the underlying surface radiate in the long-wave range. In general, the absorption coefficient and heat capacity are specific for the atmospheric layers and are everywhere positive. In the model, the radiation balance of a segment of the atmospheric column above a unit area of the underlying surface determines the change in the internal energy and the volume occupied by the segment.The pressure value always remains equal to the weight of a part of the atmospheric column above the segment (hydrostatic hypothesis). The underlying surface is always in the state of radiation equilibrium. Under these assumptions: a) there is a single equilibrium vertical temperature distribution in the column and corresponding air pressure and density distributions (they are calculated using the hydrostatic assumption and the equation of a state of the ideal gas); b) the temperature distribution is asymptotically stable, i.e. any other initial distribution of non-negative temperature values tends with time to equilibrium uniformly on the vertical. Thus, one can expect that the numerical analogs of the model considered in this work will also be stable, which is important for the computational implementation of both the one-dimensional model and its three-dimensional version.

scholarly journals Supercomputer model of dynamical dusty gas with intense momentum transfer between phases based on OpenFPM library

2021 ◽  
Vol 2099 (1) ◽  
pp. 012056
Author(s):  
Vitaliy Grigoryev ◽  
Olga Stoyanovskaya ◽  
Nikolay Snytnikov
Keyword(s):  
Continuous Medium ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Point Explosion ◽  
Vector Data ◽  
Sph Method ◽  
One Dimensional ◽  
Gas Dynamic ◽  
Plane Sound ◽  
Gas Dynamic Equations

Abstract The paper considers the solution of model gas-dynamic problems (propagation of plane sound wave, one-dimensional shock tube problem, three-dimensional problem of a point explosion in a continuous medium) in the case of a gas-dust medium. The interaction of dust and gas was taken into account using the IDIC method within the SPH method used to solve gas-dynamic equations. An important feature of the work is the use of the open computational package OpenFPM, which makes it easy to carry out parallel computations. The main advantage of this package is the ready-made (implemented by the authors of the package) and intuitive, automatically parallelizable vector data structures, the use of which is identical both in the case of calculations on a personal computer and in the case of using supercomputer resources. The paper analyzes the efficiency of parallelization of numerical solutions of the considered problems.

Generalized Application of Periodic Symmetry in Molecular Simulations

2003 ◽  
Author(s):  
Li Pan ◽  
Don Metzger ◽  
Marek Niewczas
Keyword(s):  
Molecular Simulations ◽  
Model System ◽  
New Method ◽  
Simulation Algorithm ◽  
Element Analysis ◽  
Kinematic Constraints ◽  
One Dimensional ◽  
Novel Method ◽  
External Forces ◽  
Physical Boundary

Periodic symmetry is widely used in molecular simulations to mimic the presence of an infinite bulk surrounding an N-atom model system. However, the traditional methods of applying periodic symmetry end up enforcing over-restrictive kinematic constraints between the periodic boundaries. After a brief overview of the periodic symmetry, the nature of the constraint is discussed briefly in this paper. Thereafter, the objective is to provide a means to ensure that periodicity is upheld while avoiding unnecessary constraint of the repeating cell boundaries. This paper demonstrates the usual application of periodic symmetry into a molecular simulation algorithm through a typical example. Meanwhile, a novel method is introduced, which uses equivalent external forces applied to physical boundary atoms. Comparisons between the classic treatment and the new method using one-dimensional and two-dimensional models are made. Moreover, the potential application of the new method in regular Finite Element Analysis is discussed.

Sign in / Sign up

Export Citation Format

Share Document