S.V. Boldyrev*, S.I. Kharchuk**
INFLUENCE OF THE CORRECTION FUNCTIONS IN NONLINEAR TURBULENCE MODEL EQUATIONS ON THE RESULTS OF PULSATED SEPARATED FLOW CALCULATION IN CHANNEL BEHIND DIAPHRAGM // Transactions of Academenergo. -2015. -N 4. –P.P. 7-21.
e-mail: underminder@mail.ru, kharchyk@mail.ru
*Naberezhnye Chelny institute (branch) of Kazan Federal University
**Kazan power-engineering university
Keywords: pulsated flow, separated flow, turbulent flow, numerical simulation, turbulence model, reattachment length
Abstract
Offered in this article modification variant of quadratic High-Reynolds number k-e turbulence model is intended for more accurate prediction of the local characteristics of pulsated separated turbulent flow of compressible gas in channel behind diaphragm at rather high values of Strouhal number. Correction functions C1 and k values are determined at Sh = 0..0.5, Re = 17000 and Re = 33000 regimes. Verifying calculations were carried out. Simulation results (skin-friction and pressure coefficients, reattachment length, turbulent characteristics) were compared with experimental data. It was established that original turbulence model permits necessary calculation accuracy only at Sh < 0.07.
A.S. Burov*, G.A. Glebov**
NUMERICAL AND EXPERIMENTAL RESEARCH TWO-PHASE SWIRLING FLOW IN DIRECT-FLOW CYCLONE (PART I) // Transactions of Academenergo. -2015. -N 4. –P.P. 22-35.
e-mail: masteru_2004@rambler.ru, Glebov_G_A@mail.ru
* Joint-stock company «Kazan Experimental Design Office « Union »
** KNRTU-KAI named after. A.N. Tupolev
Keywords: Direct-flow cyclone, separation, two-phase flow, numerical method, turbulence model, structure of swirling flow, efficiency of purification.
Abstract
In this work has been made numerical research of the two-phase flow in direct-flow cyclone. Based on comparison of numerical and physical experiments was selected optimum turbulence model to calculate the test flow. It shows that the degree of gas cleaning from solids essentially depends on the size and shape of the particles. Calculation method applicable for the cyclones of different sizes in a wide range of operating parameters.
E.K. Vachagina, G.R. Khalitova, A.A.Kaynova, A.I. Kadyirov
Investigation of rheological behavior for viscoelastic fluid based on various models for SKI-3 // Transactions of Academenergo. -2015. -N 4. –P.P. 36-53.
e-mail: vachaginae@mail.ru, halitova-galia@mail.ru, anastasiya-kaynova@mail.ru, aidarik@rambler.ru
Kazan Scientific Center of Russian Academy of Sciences
Key words: viscoelastic fluid, rheological behavior, viscous, relaxation time, secondary flow.
Abstract
The results of experimental measurements of SKI-3 samples are presented in this paper. Experimental results are used to define rheological parameters of three rheological models (Giesekus, Phan-Thien-Tanner, Vinogradov-Malkin). The analytical solution for a partial problem is given to validate the numerical method which is integrated in COMSOL Multiphysics. Rheological behaviors of SKI-3 flows in prismatic channel with square cross section are numerically investigated. Differences between three rheological models of SKI-3 flows are observed.
V.N.Shlyannikov1,2, A.V.Tumanov1, A.M.Tartygasheva1
DAMAGE GROWTH IN FUSELAGE PANELS UNDER BIAXIAL LOADING // Transactions of Academenergo. -2015. -N 4. –P.P. 54-71.
e-mail: shlyannikov@mail.ru, tymanoff@rambler.ru
1 Kazan Scientific Center of Russian Academy of Sciences
2 Kazan National Research Technical University – KAI
Keywords: fuselage panel, biaxial loading, crack, cohesive model
Abstract
The calculation of the standard curved panels of the fuselage of the Airbus with windows, frames and stringers carried out. Three types of biaxial loading panels were considered with straight and curved cracks of varying lengths. In FEM-meshes of panels have been implemented special area for fracture process zone modeling with special cohesive elements. The calculations are made for the conditions of the combination pressurization of the fuselage by internal pressure and longitudinal forces. The crack trajectory calculations are performed on the base of the strain energy density parameter for the considered loading conditions of the panel. The estimation of fracture damage zone influence on the general and the local stress-strain state under biaxial loading of straight and curved cracks for internal and external surfaces of the shell of the fuselage skin panels is given.
V.N. Shlyannikov, A.P. Zakharov
GENERALIZED FATIGUE FRACTURE DIAGRAM UNDER BIAXIAL LOADING // Transactions of Academenergo. -2015. -N 4. –P.P. 72-89.
e-mail: shlyannikov@mail.ru, alex.zakharov88@mail.ru
Kazan Scientific Center of Russian Academy of Sciences
Keywords: biaxial loading, cruciform specimen, crack growth rate, plastic stress intensity factor, generalized coordinates
Abstract
This study is concerned with numerical and experimental study of crack growth rate in cruciform specimens under biaxial loading. For the specimen geometries considered the elastic and elastic-plastic parameters of crack tip stress fields are obtained as a function of load biaxiality and dimensionless crack length. The generalized fracture mechanics parameter in form of plastic stress intensity factor for biaxial loading conditions is introduced. The biaxial loading effect on the crack growth rate in cruciform specimen geometries considered is established. The generalization of the experimental data for crack growth rate in cruciform specimens is given by a fatigue fracture diagram in the dimensionless coordinates.
A.V. Tumanov, N.V. Boychenko
SOME PECULIARITIES OF GOVERNING PARAMETER OF THE ELASTIC-PLASTIC CRACK-TIP DETERMINATION BY FINITE ELEMENT METHOD // Transactions of Academenergo. -2015. -N 4. –P.P. 90-100.
e-mail: tymanoff@rambler.ru, tasha1203@mail.ru
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: elastic-plastic stress intensity factor, plasticity, finite element method
Abstract
This work is devoted to determination of the range of stable values of governing parameter in the form of In-integral near the crack tip. The subjects for study are a plate with infinite size containing a through thickness crack and compact specimens with a variation of the crack length and the applied load. Various methods for stress-strain diagrams approximation are used to determine the parameters of the stress-strain state in the numerical calculations.
The advantages of the Ramberg-Osgood model for description of elastic-plastic material are shown in the present paper. The region of stable values of the governing parameter is established and substantiated. It is proved that the position of this region is independent from the geometry of the cracked body.
A.V. Tumanov
A CREEP-FATIGUE TEST METHOD AND AN ALGORITHM OF RESULTS INTERPRETATION FOR THE CRACK GROWTH RESISTANCE CHARACTERISTICS DETERMINATION // Transactions of Academenergo. -2015. -N 4. –P.P. 101-110.
e-mail: tymanoff@rambler.ru
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: elastic-plastic stress intensity factor, plasticity, finite element method
Annotation
The algorithm of a creep-fatigue test and a results interpretation method is described. The algorithm is allows to obtain a crack growth rate diagram in terms of the creep stress intensity factor. The proposed algorithm is implemented on compact specimens made of steel Р2М. It is shown that the creep stress intensity factor approach takes into account the crack front tunneling effect.
A.Z. Daminov, Ju.V. Karaeva
MODELING AND PREDICTION OF HEAT CONSUMPTION IN RESIDENTIAL AREAS OF A SETTLEMENT // Transactions of Academenergo. -2015. -N 4. –P.P. 111-118.
e-mail: daminov@list.ru, julieenergy@list.ru
Kazan Scientific Centre Russian Academy of Sciences
Keywords: modeling, long-range forecasting, heat energy, settlement.
Abstract
A mathematical model of heat consumption prediction in residential areas of settlements is developed. Using the model will allow to carry out the following actions: forecasting and analytical work; choice decisions, new technologies, projects and programs to achieve reliable energy conservation; forming the scientific and technical policy, consistent with the requirements of an innovative economy; comprehensive improvement of the energy sector.
J.А. Manigomba, N.D. Chichirova
ELECTRICAL ENERGY ORGANISATION IN REPUBLIC OF BURUNDI // Transactions of Academenergo. -2015. -N 4. –P.P. 119-125.
e-mail: аmanigomba@yahoo.fr
Kazan State Power Engineering University
Keywords: thermal power stations, biomass, electric power deficiency, minerals, ecology.
Annotation
The paper analyses the power electric situation of Republic of Burundi, is shown the main types of existing and planned power stations. Has been done evaluation of production of electrical energy and was given the way of solving the problem of insufficient power energy, based on the creation of environmentally and ecologically thermal power stations which can use diesel fuel and biomass. Recycling of waste of cities and industries will solve the environmental problems.
V.A. Khrustalev1,2, M.V.Garievsky2
THE EFFECT OF VARIABLE MODES FOR ECONOMICAL OPERATION OF POWER UNITS // Transactions of Academenergo. -2015. -N 4. –P.P. 126-137.
e-mail: khroustalevva@mail.ru, garievsky.michael@gmail.com
1 Yuri Gagarin State Technical University of Saratov
2 Saratov center of science of Russian academy of sciences
Keywords: nuclear power plants, gas turbines, efficiency, safety, combined cycles
Abstract
In the article the questions of increase of safety and efficiency of nuclear power plants by combining gas turbines. Calculated frequency of core damage in case of power failure of the power unit for different redundancy schemes. It is shown that the reservation of own needs NPP are constantly existing gas turbine units to reduce the risk of severe accidents in case of a nuclear power plant. In addition to the use of gas turbines as a backup source, it is possible to effectively utilize the heat energy of the combustion products and use it in the heat-scheme of NPP. The calculation of technical and economic indicators of the various options and technical solutions for the efficient combination of gas turbine plants with nuclear power units.