Science

Problems of Continuum Mechanics

(scientific seminar and conference)

Kazan, Russia

D.A.Gubaidullin

Institute of Mechanics and Engineering; Kazan Science Center, RAS, Kazan, RUSSIA

The Scientific Seminar "Problems of Continuum Mechanics" works in the Institute of Mechanics and Engineering, Kazan Science Center RAS. The Chairman of the Seminar is Director of the Institute Corresponding Member of the RAS D.A.Gubaidullin. Problem reports and dissertations of researchers of the Institute and scientists from other organizations are presented and discussed at the Seminar. Main scientific directions for presentation are:

·       non-linear mechanics of thin-walled constructions, hydroaeroelastic and wave systems;

·       dynamics of multiphase multicomponent media in porous structures and technological plants;

·       non-linear stability theory of control systems with changeable structure.

The following reports were presented at the Seminar in 2008 and at the Section of Final Scientific Conference'2008.

May 16, 2008

D.T.Suyucheva (The Kazan State University).

The interaction of a contaminated groundwater flow with the wells. On materials of the thesis submitted for Candidate of Sciences Degree, speciality 01.02.05 - mechanics of liquid, gas and plasma. Scientific chief  DrSc E.V. Skvortsov reviewer DrSc A.I.Nikiforov.

The interaction of a contaminated groundwater flow with the wells was studied. The capture zone boundary was calculated in the frame of the potential flow scheme. The critical flow rates were found at which capture zone gaps appeared.

May 16, 2008

B.G.Gogolashvili (The Kazan State University).

Gravity-driven wetting front instability and fingering in unsaturated porous media. On materials of the thesis submitted for Candidate of Sciences Degree, speciality 01.02.05 - mechanics of liquid, gas and plasma. Scientific chief DrSc A.G.Egorov, reviewerDrSc A.I.Nikiforov.

In this work the problem of unsaturated flow and transport in coarse homogeneous porous media was studied. The new approach taking into account relaxation and hysteretic effects was developed for modelling widely known fingering phenomena. The verification of the proposed model against broad range of experimental data show good agreement and validity of the model.

June 5, 2008

A.V.Tsepaev (IME).

The parallel algorithms to solve the three-dimensional flow problems in porous media. On materials of the thesis submitted for Candidate of Sciences Degree, speciality 01.02.05 - mechanics of liquid, gas and plasma. Scientific chief PhD P.A.Mazurov, reviewer DrSc A.I.Nikiforov.

Two parallel algorithms are developed to solve the three-dimensional flow problems on a coarse mesh with fine mesh segments. The first algorithm has been suggested to solve the equation for pressure, the second one to solve the equation for saturation. These algorithms show their efficiency which grows with increasing number of fine mesh segments.

July 9, 2008

A.I.Abdullin (IME).

Numerical methods of solution of the filtration inverse problem in porous-fractured media. On materials of the thesis submitted for Candidate of Sciences Degree, speciality 01.02.05 - mechanics of liquid, gas and plasma. Scientific chief DrSc M.H. Khairullin. Reviewer DrSc V.L.Fedyaev.

In this work the influence of dependence of fracture permeability from pressure on pressure variation curves in the fractured-porous layer is investigated. Numerical algorithm for identification of permeability of fractures in deformable naturally fractured reservoir by the method of descriptive regularization is developed. Numerical algorithm for estimation of vertical well bottom zone state in naturally fractured reservoir is developed. The author researches the influence of naturally fractured reservoir deformation on change of pressure build-up and draw-down processes in reservoir, dependence of fracture permeability on pressure.

October 31, 2008

T.F.Khalitova (IME).

Strong compression of no spherical gas bubble in a liquid. On materials of the thesis submitted for Candidate of Sciences Degree in physics and mathematics, speciality 05.13.18 - Mathematical modeling, numerical methods and complexes of programs. Scientific chief DrSc A.A.Aganin, reviewer DrSc P.P.Osipov.

A numerical technique to study strong compression of a cavitations bubble with an axially symmetric deviations from spherical shape is proposed. The motion of the vapor in the bubble and surrounding liquid is governed by equations of a compressible liquid dynamics taking into consideration heat conductivity, heat-mass exchange, with the realistic equations of state. Working capacity of the technique and its efficiency is shown in the large number of problems.

December 11, 2008

P.G.Velikanov (Kazan State University).

Orthotropic plates and shells calculation by the Boundary Elements Method. On materials of the thesis submitted for Candidate of Sciences Degree, speciality 01.02.04 - mechanics of a deformable firm body. Scientific chief DrSc Y.P.Artyukhin, reviewer PhD V.G.Malakhov.

The work is devoted to the further development of the Boundary Elements Method (BEM) for the decision of problems of linear and nonlinear deformation of orthotropic (rectilinearly and curvilinear) and isotropic multicoherent plates laying on the complex elastic basis and flat shells with a difficult contour and any boundary conditions, admitting continuous and step - variable change of rigidity, at the connected influences of physical (temperature) fields and mechanical (located and distributed on some area and law) loadings. The technique of the decision of a contact problem of a bend isotropic plate on the elastic Vinkler's basis under action of a rigid stamp also is offered. For the decision of the put problems (BEM) matrixes of the fundamental decisions of systems of the differential equations previously should be known. The new technique of the decision of the put problem assumes a finding of the associated differential operator, which reduces a finding of a matrix of the fundamental decision to simple differentiation of scalar function according to the associated differential operator.

March 25, 2009

M.N.Shamsiev (IME).

Investigation of oil and gas reservoirs and wells at unsteady modes of a filtration.

On materials of the thesis submitted for Doctor of Sciences Degree in technique, specialty 01.02.05 - mechanics of liquid, gas and plasma. Scientific consultant DrSc, Prof. M.H.Khairullin, reviewers DrSc P.G.Danilaev, DrSc A.I.Nikiforov.

Numerical solutions of the inverse coefficient problems of the filtration theory are considered. The new approach to interpretation of results of hydrodynamic researches of wells within the limits of models of elastic, non-linear - elastic modes of a filtration on the basis of the regularization theory is developed. The method for estimating skin - effect of vertical wells is offered. The processes of formation and decomposition of gas hydrates in the porous media and well bore of vertical gas well are investigated. The process of dissociation of gas hydrates in the porous media is considered at cyclic thermal influence. The mathematical model of the process of formation and decomposition of gas hydrate in the system is created.

 

The following report was presented at section Sessions of the Final Scientific Conference'2008 of the Kazan Science Center RAS:

February 9, 2009

D.A.Gubajdullin, R.N.Gafiyatov, A.A.Nikiforov (IME).

Propagation of acoustic waves in two-fractional bubble environments of different composition. A closed system of the equations of motion of a two-fractional mixture of liquid with bubbles of different gases and various initial radiuses which has been reduced to one differential equation is presented. The dispersion equation determining propagation of weak perturbations in the given mixture has been received. For a mixture of water with bubbles of air and helium two local maximums in dependence of attenuation factor from frequency are revealed. The influence of the account of two-fractional composition on evolution of pressure impulse has been shown.

A.L.Tukmakov (IME).

Dependence of the prevailing mechanism of drift of the firm particle in the nonlinear acoustic field from the parity between the constant of time and wave characteristics. The criterion allowing depending on a parity between a constant of time of a particle and wave characteristics to define the prevailing mechanism and a direction of drift of a firm spherical aerosol particle in a nonlinear wave field of the closed acoustic resonator is analyzed. As wave characteristics the time of increase of front of compression and duration of an acoustic wave are considered. The gas velocity field contains the periodic nonlinear waves and an acoustic current, movement of particles occurs under the influence of Stokes, Archimedes and the added mass forces.

P.P.Ossipov (IME).

Impacts of main forces on a particle drift in one-dimensional periodical field in tube. One-dimensional problem of solid particle drift in periodic field of velocity with shock is studied numerically. The impact of the Stocks, Archimedes, Basset, added mass forces, as well as Oseen-type correction on a drift velocity is revealed.

D.A.Gubaidullin (IME), R.G.Zaripov (IME), R.G.Galiullin (KSU), L.A.Tkachenko (IME).

Motion of a spherical particle at forced longitudinal oscillations of gas in an open tube. The motion of a spherical particle is experimentally investigated at forced longitudinal oscillations of gas in an open tube near the subharmonic resonance. The influence of frequency of excitation of gas and lengths of a tube on an oscillation swing and mean velocity of a motion of a particle is investigated. The dependence of mean velocity of a particle on frequency of excitation of gas has the resonant shape. The comparison of the received results with the experimental data in case of the closed pipe is given.

S.K.Zaripov, A.K.Gilfanov, D.V.Maklakov (KSU).

Aerosol sampling at the extended range of ratio of wind and aspiration velocities. The aerosol aspiration into a thin-walled sampler horizontally oriented in extended range of ratio of wind and aspiration velocities is numerically investigated. The velocity field of carrying agent on the basis of Boundary Element and Finite Volume methods within models of a potential and viscous flow of incompressible fluid is found. The aspiration efficiency was calculated in the region of a very small and very large ratio of wind and sampling velocities. The gravity influence is discussed. The numerical results are compared with known experimental data and approximate formulas.

V.B.Repin, A.V.Repina (KSTU), R.G.Zaripov (IME).

Dynamic pressure of a pulsing jet at nonlinear oscillations of gas in the open tube. At excitation of resonant oscillations of gas in a tube periodically oscillating piston from the open end of a tube forms a pulsing jet which dynamic pressure submits to a classical relation with coefficient 1/7. It is shown, that this relation is true in the case of the formation of breaks in a profile of a wave. The theoretical relation allowing calculate a condition of break formation at the first linear resonance well is received.

A.A.Aganin, A.I.Davletshin (IME).

Simulation of interaction of gas bubbles in a liquid with allowing for their small asphericity. A mathematical model of interaction of gas bubbles in a liquid with allowing for small distortions of the bubble surfaces is proposed. It is of the fourth order of accuracy relative to the ratio of the characteristic radius of the bubbles to the characteristic distance between them. In the model, the effects of the liquid viscosity and compressibility are taken into account, the gas in the bubbles is assumed homobaric. For its validation, the known solution of the problem of collapse of an empty cavity near a plane rigid wall, which was obtained by the boundary element method, has been used.

L.A.Kosolapova, V.G.Malakhov (IME).

Nonlinear no spherical oscillations of a gas bubble in liquid with allowing for translation. A mathematical model of nonlinear no spherical oscillations of a gas bubble in liquid has been developed. The bubble is considered to be axisymmetric and its spatial movement to occur along the vertical axis. The shape of the bubble surface is presented in the form of a series over the spherical harmonics and the governing equations are written with accuracy of square of the amplitude of the spherical bubble shape distortion. Viscosity and compressibility of the liquid are approximately considered. The comparison with the results of other authors is presented.

T.F.Khalitova, N.A.Khismatullina (IMM).

Strong compression of ellipsoidal cavitations bubble. The one of possible scenario of vapor dynamics inside the ellipsoidal cavitations bubble in the final stage of its strong compression is revealed and described. A no spherical deformation of the shock wave during its motion from the phase boundary to the small neighborhood of the bubble center is shown. It is established that on the stage of a moderate deformation of a shock wave the maximum pressure and temperature values in the no spherical case can be larger than in spherical case.

M.H.Hairullin, M.N.Shamsiev, P.E.Morozov, I.T.Salimyanov (IME).

Criteria of fitting of wells and estimation of efficiency of hydraulic rupture of a reservoir bed on the basis of hydrodynamic researches of wells. Computation algorithms for modelling of liquid inflow into a well with a fracture of hydraulic rupture of a reservoir bed are offered. The analysis of the influence of conductivity and the length of a fracture on producing ability of well is carried out. The method for the definition of conductivity and length of a fracture of hydraulic rupture of a reservoir bed is created. As the initial information curves of pressure recovery which have been taken in vertical wells are used.

P.E.Morozov (IME).

Analytical solutions of fluid flow problems towards a horizontal well in naturally fractured reservoir. The analysis of analytical and semi-analytical solutions of fluid flow problems toward a horizontal well in an infinite reservoir is carried out. The influence of skin-effect on flux distribution along the well bore face and on dynamics of the pressure change in a horizontal well is investigated. The analytical and semi-analytical solution of a steady-state problem for horizontal well in a circular reservoir is obtained. It is shown that the semi-analytical solution is in good agreement with the experimental data.

A.I.Abdullin (IME).

Inverse problem of filtration in a deformable porous-fractured media. A numerical algorithm for solving the inverse coefficient problem of filtration in a deformable porous-fractured media is suggested. The algorithm uses a priori information of the required solution and is based on the method of descriptive regularization. The dependence of permeability of fractures from the pressure is taken into account when interpreting hydrodynamic investigations of vertical and horizontal wells in the petroleum reservoir. The dependence of permeability is found in the class of monotone and convex functions.

R.F.Nurullin, A.I.Nikiforov (IME).

About efficiency of thermogels use in water flooding of oil reservoirs. The water flooding of oil reservoir with thermo gel is simulated in the work. Two-phase filtration of incompressible immiscible fluid into the trilaminar reservoir is considered. The influence of thermogels on oil recovery and time of reservoir exploitation is analyzed.

A.I.Nikiforov, R.V.Sadovnikov, G.A.Nikiforov (IME).

Modeling of fines release by filtration flow from porous bed. In this work, we present mathematical model to describe the reductions of porosity and permeability in two-phase flow in oil reservoirs resulting from migration of fines in porous media. The model equations describing the release and capture mechanisms of particle by porous bed have been obtained. Numerical experiments show that the main mass of particles is carried out to wells by water.

R.V.Sadovnikov, A.I.Nikiphorov (IME).

Identification of permeability tensors of blocks and fractures of fractured porous reservoir. This work is devoted to parallel realization of some algorithms for flow parameters identification of fractured porous reservoir on hydrodynamic tests results for system of wells. The work was performed in the framework of Program No 14 for basic research established by the Presidium of the Russian Academy of Science under the title "Fundamental problems of computer science and information technologies".

G.A.Nikiforov, R.V.Sadovnikov (IME).

Solution of the two-phase filtering problem in variable "velocity-saturation". The development of a method of the numerical modeling of a two-phase filtering problem in variables "speed-saturation" on the basis of a control volumes method is the purpose of the present work. Two families of control volumes are used. The first is used at approximation of the equations for a divergence of speed and for a saturation, the second is used at approximation of the equation for a rotor of speed. The equation for saturation is approximated by WENO scheme. Possibilities of this method are shown on the decision of some problems.

A.V.Elesin, A.N.Gabidullina, A.Sh.Kadyrova (IME).

Using parallel algorithms in problem of hydraulic conductivity identification. A new algorithm for the minimization of the residual function with consideration of a priori comparative information on parameter values is proposed. The algorithm is used for the numerical solution of a model problem of hydraulic conductivity identification for a three-dimensional anisotropic confined aquifer. The model task is solved on the multiple processor system with using parallel calculations.

P.A.Mazurov, A.V.Elesin, A.Sh.Kadyrova (IME).

Quasi-Newton two-step method of the residual function minimization. Quasi-Newton two-step method is proposed for the minimization of the residual function taking into account the ravine of minimizing function. The displacement of the parameters is realized in two steps on each iteration of this method. This allows to go round the bends of the ravines bottom and to accelerate the minimization process. The method is used for the numerical solution of a model problem of hydraulic conductivity identification for a three-dimensional anisotropic confined aquifer and for the minimization of test functions. The effectiveness of two-step method is shown in the comparison with one of the variant of Levenberg-Marquardt method.

V.L.Fedyaev, I.V.Morenko, B.A.Snigerev (IME).

Optimization of the cooling tower. The problems of the structural and parametric optimization are studied. In the present work the mathematical formulation of the cooling tower basic process is described. The nozzle height is optimized.

February 10, 2009

N.K.Galimov, S.N.Yakupov (IME).

Research of mechanical characteristics of spherical membranes. The development of the experimentally-theoretical approach of definition of mechanical characteristics of the membranes having the initial spherical form is described. Theoretical parities are received by Bubnov-Galerkin method for nonlinear elastic - rubber like materials by Cuppus, and also plastic materials by Ilyushin. The examples of definition of mechanical characteristics of spherical rubber membranes with various quantities of apertures, and also the spherical membranes made of a plastic material (a plastic ball) are considered. The corresponding conclusions are made.

N.M.Yakupov, A.A.Abdjushev, I.H.Miftakhutdinov (IME).

Research of influence of treating overlays on the vat of panels with system of cracks and the analysis of mechanical characteristics of overlays at temperature influence. The results of researches of pressure intensity distribution in the panel with three parallel cracks, and also installation for the definition of mechanical characteristics of strips from the thermofocused material under temperature influence are described. The installation consists of tightening elements, a dynamometer, heat source - an air heater. The efficiency of use of "treating overlays>, and also the possibility of rational placing of such overlays are marked. The conclusions are made.

H.G.Kijamov, N.M.Yakupov (IME).

To calculation of two-dimensional and three-dimensional elements of designs. It is noticed, that three-dimensional objects were the first building creations of mankind. After the millennium thin-walled designs appeared. In the XX-th century thin-walled designs of difficult geometry appeared. However in the view of the development of modern calculation methods at first the calculation methods of two-dimensional objects of difficult geometry, and then three-dimensional have been developed. The calculation of two-dimensional and three-dimensional objects of difficult geometry is developed on the basis of the uniform approach based on synthesis of idea of preliminary parameterization and of a finite-element method, splines variant. The examples are considered.

N.M.Yakupov, R.R.Ginijatullin, S.N.Yakupov (IME).

Research of mechanical characteristics of the thin-walled elements subject to corrosion deterioration at influence of a magnetic field. During corrosion deterioration, along with geometry changes, a process of material destruction takes place. Works on studying of magnetic field influence on the process of corrosion deterioration of thin-walled elements of designs on mechanical characteristics change of a material began. The samples being in an excited environment were exposed to the magnetic field influence. For the definition of mechanical characteristics of a samples material, the experimentally-theoretical approach was used. The results show, that the magnetic field influences corrosion deterioration.

A.R.Nurgaliev (IME).

Experimental installation for test of thin-walled elements of the designs subjected to variable loading and being in the excited environment. The researches of metal membranes under static loading in an excited environment that were carried out have shown that deformations of elements of designs activate corrosion process. The influence of dynamic loadings on the loaded metal elements of the designs which are being in an excited environment is practically poorly studied. To study the change of mechanical characteristics of thin-walled elements during corrosion deterioration under dynamic loadings experimental installation on the basis of an internal combustion engine is developed. Debugging works come to the end.

R.I.Shafigullin, N.M.Yakupov (IME).

Experimental installation for keeping the thin-walled elements in the mixed liquid environment. The phenomenon of corrosion deterioration of elements of the designs subjected to the influence of an excited environment with variable density, owing to formation of vials is considered. Such phenomena are observed in various elements of the designs subjected to the influence of the mixed liquid, in particular, is observed in elements of courts near the rowing screws. For research experimental installation has been created. At installation work the working environment in which samples are maintained for a preset time is created. Further tests of samples by an experimentally-theoretical method are carried out, the conclusions are made.

A.K.Shalabanov (Academy of control <TISBI >).

The analysis of stress-strained state of the cylindrical shell on the basis of the specified equations of shells theory.

B.A.Snigerev (IME).

Creeping flow of viscoelastic fluid with free surface at non-isothermal condition. Numerical simulation of flow of viscoelastic fluid with free surface, which is realized in entrance and output flow of polymeric liquid in extrusion die was performed. The flow of liquid is described by equations of conservation of mass, momentum and thermal energy with rheological constitutive equation of Giesekesus. The ratio of extrusion in dependence of the parameters of rheological model are received.

I.V.Morenko (IME).

Nonisothermal laminar viscous flow around a body with built-in vortex cells. Forced convection heat transfer from an unconfined cylinder with built-in vortex cells in the steady cross-flow regime has been studied in the range of 1<Re<200. The influence of the cell depth on the drag, Nusselt number and other parameters are analyzed in detail.

M.S.Ganeeva, V.E.Moiseeva, Z.V.Skvortsova (IME).

Computation of the nonlinear stress-strained state of non-shallow shells of revolution under a wind loading. The effects of wind-like loading on the dome of large reservoir designed as a shell of revolution with central hole are investigated, in case of intensive loading when ultimate loads of instability are reached. The algorithm of computation of geometrically and material nonlinear stress-strained state allowing to receive critical parameter values of non-axisymmetric loading is proposed. The results of computations for hemispherical dome are submitted and analyzed.

A.I.Malikov (IME).

Robust Control of Electromechanical Systems. The matrix comparison systems method is developed for the analysis of robust stability and ellipsoidal state estimation for electromechanical control systems with uncertain perturbations and changes of parameters. The conditions of convergence and bounded ness of ellipsoidal estimations, the conditions of robust stability, the invariance for continuous and discrete systems with incomplete description of model are received. The ways of synthesis of the optimum regulators providing robust stability and quality of transients are offered.

U.N.Zakirov (IME).

Exact solution of equation of a controllable motion of concentrated variable mass. For a broad band of velocities and gravity potential the equations of a controllable motion of concentrated variable mass (CVM) are obtained on the basis of generalization of a Newton's laws on the basis of satellite measuring of celestial bodies. By a method of exuberant measuring using Riemannian geometry for the first time gravitational oscillations of CVM are obtained at its motion on a circular orbit, that is the contribution in the precision ballistics of a controllable motion.




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