scholarly journals The piston problem in hyperelasticity with the stored energy in separable form

2016 ◽  
Vol 22 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Serge Ndanou ◽  
Nicolas Favrie ◽  
Sergey Gavrilyuk
Keyword(s):  
Stored Energy ◽  
Initial State ◽  
Piston Problem ◽  
Remarkable Property ◽  
Transverse Waves ◽  
Solid Density ◽  
Separable Form ◽  
Similar Solutions ◽  
Rarefaction Shock ◽  
Linearly Degenerate

The piston problem for a hyperelastic hyperbolic conservative model where the stored energy is given in separable form is studied. The eigenfields corresponding to the hyperbolic system are of three types: linearly degenerate fields (corresponding to the contact characteristics), the fields which are genuinely nonlinear in the sense of Lax (corresponding to longitudinal waves), and, finally, nonlinear fields which are not genuinely nonlinear (corresponding to transverse waves). Taking the initial state free of stresses, we presented possible auto-similar solutions to the piston problem. In particular, we have shown that the equations admit transverse shock waves having a remarkable property: the solid density is decreasing through such a shock, it is thus a ‘rarefaction’ shock.

About of the injection of hydrate-forming gas into a layer of snow saturated with the same gas

2017 ◽  
Vol 12 (2) ◽  
pp. 219-226 ◽  
Author(s):  
A.S. Chiglintseva ◽  
V.Sh. Shagapov
Keyword(s):  
Gas Injection ◽  
Injection Pressure ◽  
Initial State ◽  
Pressure Fields ◽  
Gas System ◽  
Formation Zone ◽  
Snow Water ◽  
Self Similar ◽  
Temperature And Pressure ◽  
Similar Solutions

The problem of injecting a hydrate-forming gas into a snow massif in the initial state saturated with the same gas are solved. Self-similar solutions describing the temperature and pressure fields, the distribution of snow, water, hydrate and gas saturation in the massif are constructed. It is shown that when forming a hydrate, depending on the initial thermobaric state of the ice-gas system, as well as the intensity of gas injection, it is possible to distinguish various characteristic zones in the filtration region that differ in their structure and length. It has been established that with an increase in the gas injection pressure and a decrease in the initial snow-saturation of the massif, the volume formation zone of the hydrate increases.

A similarity problem of a porous material drying

2008 ◽  
Vol 6 ◽  
pp. 75-81
Author(s):  
D.Ye. Igoshin
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Gas Mixture ◽  
Dimensional Problem ◽  
Vapor Mixture ◽  
Initial State ◽  
One Dimensional ◽  
Similarity Problem ◽  
Self Similar ◽  
Similar Solutions

The plano-one-dimensional problem of heat and mass transfer is considered when a porous semi-infinite material layer dries. At the boundary, which is permeable for the gas-vapor mixture, the temperature and composition of the gas are kept constant. Self-similar solutions are set describing the propagation of the temperature field and the moisture content field arising when heat is supplied. The intensity of dry flows is studied, depending on the initial state of the wet-porous medium, as well as the temperature and concentration composition of the vapor-gas mixture at the boundary of the porous medium.

Oblique waves in steady supersonic flows of Bethe–Zel’dovich–Thompson fluids

2018 ◽  
Vol 855 ◽  
pp. 445-468 ◽  
Author(s):  
Davide Vimercati ◽  
Alfred Kluwick ◽  
Alberto Guardone
Keyword(s):  
Classical Case ◽  
Dynamic Regime ◽  
Oblique Shock ◽  
Heat Conducting ◽  
Shock Adiabats ◽  
Initial State ◽  
Gas Dynamic ◽  
Classical Gas ◽  
Self Similar ◽  
Similar Solutions

Steady self-similar solutions to the supersonic flow of Bethe–Zel’dovich–Thompson fluids past compressive and rarefactive ramps are derived. Inviscid, non-heat-conducting, non-reacting and single-phase vapour flow is assumed. For convex isentropes and shock adiabats in the pressure–specific volume plane (classical gas dynamic regime), the well-known oblique shock and centred Prandtl–Meyer fan occur at a compressive and rarefactive ramp, respectively. For non-convex isentropes and shock adiabats (non-classical gas dynamic regime), four additional wave configurations may possibly occur; these are composite waves in which a Prandtl–Meyer fan is adjacent up to two oblique shock waves. The steady two-dimensional counterparts of the wave curves defined for the one-dimensional Riemann problem are constructed. In the present context, such curves consist of all the possible states connected to a given initial state (namely, the uniform state upstream of the ramp/wedge) by means of a steady self-similar solution. In addition to the classical case, as many as six non-classical wave-curve configurations are singled out. Moreover, the necessary conditions leading to each type of wave curves are analysed and a map of the upstream states leading to each configuration is determined.

scholarly journals On the interaction of two particles

1936 ◽  
Vol 154 (882) ◽  
pp. 487-500 ◽  
Keyword(s):  
Coulomb Interaction ◽  
Quantum Electrodynamics ◽  
Life Time ◽  
Coulomb Force ◽  
Matrix Elements ◽  
Initial State ◽  
Final State ◽  
Transverse Waves ◽  
Longitudinal Waves ◽  
Light Quanta

The problem of the interaction of two particles has been treated by Møller, using a correspondence method, and the same formula for the interaction has been found by Bethe and Fermi and by Fock, using the methods of Quantum Electrodynamics. In these derivations only free particles have been considered, and the object of this paper is to consider bound particles, taking into account the possibility of one of the particles having a finite life-time in its initial state. An example of this kind appears in the theory of the internal conversion of γ-rays, where we have to consider the interaction of a nuclear particle in an excited state with an electron in the K-shell. On the non-relativistic theory, the interaction of two particles is given simply by the Coulomb force, whereas according to Quantum Electrodynamics any interaction must take place via the field, if we suppose this to include longitudinal waves as well as transverse ones. It has been shown, however, that the longitudinal waves are equivalent to the Coulomb interaction, and in practice it is easier to replace this part of the field by Coulomb forces. Let us suppose that we have a system of two particles which makes a radiationless transition from a state Ψ i to a state Ψ f . The Coulomb interaction has non-zero matrix elements for this transition, which may be written down, but to find the effect of the transverse waves in the field (light quanta) we must proceed as follows. We assume the system to interact with the field, and pass over first into a state Ψ q , where, if we performed an experiment, there would be a definite probability of finding light quanta present. From this state it passes over to the final state with no quanta present. This is the procedure we shall adopt to calculate the matrix elements of the interaction, and we shall show that for bound electrons also it gives the same result as Møller’s theory.

Criterion of Hyperbolicity in Hyperelasticity in the Case of the Stored Energy in Separable Form

2013 ◽  
Vol 115 (1) ◽  
pp. 1-25 ◽  
Author(s):  
S. Ndanou ◽  
N. Favrie ◽  
S. Gavrilyuk
Keyword(s):  
Stored Energy ◽  
Separable Form

Tensile Failure of 55-Nitinol Wire

1975 ◽  
Vol 33 ◽  
pp. 46-47
Author(s):  
F. I. Grace
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Stoichiometric Composition ◽  
Tensile Failure ◽  
Initial State ◽  
Initial Shape ◽  
Nitinol Wire ◽  
Cscl Type ◽  
Shear Transformation

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.

Comparative study of the impact of two mechanical perforation densities on the behavior of a sandy soil

2012 ◽  
Vol 8 (1) ◽  
pp. 37-48
Author(s):  
S. Chehaibi ◽  
K. Abrougui ◽  
F. Haouala
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Water Infiltration ◽  
Cone Penetration ◽  
Initial State ◽  
Soil Water Infiltration ◽  
Good Improvement ◽  
The Impact ◽  
Positive Effect ◽  
Resistance To Penetration

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.

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