Contents
HEAT-AND-POWER ENGINEERING FUNDAMENTALS
e-mail: Dima211083@yandex.ru
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Keywords: intensification, heat-and-mass transfer, laminar flow, homophase polymerization, reactor, acrylic resin, discrete roughness
Abstract:Results of numerical research of heat-and-mass transfer processes in intensified homophase polymerization tubular reactor for continuous operation in stationary conditions of acrylic resins manufacturing process are presented in the work. Ways to influence molecular mass characteristics of polymer and a degree of transformation in the reactor are considered. Numerical calculations have shown that polymer quality depends on the geometry of a discrete rough channel and initial initiator concentration.
e-mail: rustemran@mail.ru
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Keywords: mathematical model, heat exchange intensification, viscous fluid, numerical investigations
Abstract: Numerical investigations of convective heat exchange at laminar flow of viscous mediums in the channels of heat exchangers with heat exchange intensifiers in the form of transversal discrete roughness on the example of turbine oil Tp-46 are presented in the work. Investigations are carried out with the use of periodic discrete-rough surfaces at different heat-carrying medium flow rates and boundary conditions of first-type on channel walls. Intensified channels of heat exchangers used in housing and communal services and station energetics with high-viscousity working mediums acted as the objects of the investigation. Results of numerical investigations of heat exchange and hydrodynamics processes in intensified channels of heat exchangers are presented in the form of distribution of thermal and hydrodynamic characteristics.
e-mail: ceolga@x.technion.ac.il
*Lavrentyev Institute of Hydrodynamics,**Technion-Israel Institute of Technology
Keywords: viscoplastic medium, Bingham fluid, yield stress, sedimentation, double-emulsion drop, liquid shell, drop deformation
Abstract: A numerical boundary integral method to simulate slow sedimentation of a deformable compound drop of non-Newtonian fluid shell and viscous core in an unbounded Newtonian medium is presented. The flow is considered under quasi-stationary creeping flow approximation. The Green function for the Stokes equation is used and the non-Newtonian stress is treated as a source term. Computations are performed for the gravity-induced sedimentation of shells of Bingham fluid with various shell thickness and physical parameters of the system. The focus of the study is on the dynamics of interface deformation and on the development of unyielded zones inside the shell.
e-mail: tazyukov@mail.ru , eng.hussam@mail.ru
Kazan State Technological University
Keywords: laminar flow, rheological models, shear-thinning power-law fluid
Abstract: The results are presented of extensive numerical calculations, carried out using a finite-volume method, for the fully developed laminar flow of an inelastic shear-thinning power-law fluid through a symmetric channel with a suddenly expanded and contracted part. Additional calculations are reported for more complex rheological models, including Cross, Carreau-Yasuda, which we relate systematically to the power-law model. The computational results are presented in terms of the suddenly expanded and contracted part re-circulation zone, axial velocity profiles, pressure distribution, normal and wall shear stresses at upper and lower walls. Finally, a comparison is made between the effects of each rheological model on the aforementioned parameters.
e-mail: daminov@list.ru
Research Centre for Power Engineering Problems of the Russian Academy of Sciences
Keywords: heat network, modeling, design procedure
Abstract: Mathematical modeling problem of thermohydraulic processes that occur in pipeline systems of heat networks is discussed in the paper. Mathematical model is based on a system of balance equations of energy conservation, matter and momentum of a continuous medium, taking into account the peculiarities of heat-carrying medium heat exchange with the environment during its course through the pipeline. System of algebraic equations for design of thermohydraulic processes is obtained. Design procedure of heat fluxes characterizing the heat exchange in the pipeline system is developed. An algorithm for calculating heat-carrying medium final parameters at the outlet of heat networks pipeline system at a given insulation thickness is developed.
e-mail: VGRifert@ukr.net , gorin@den.energy.gov.ua
*National Technical University of Ukraine “Kiev Polytechnic Institute”,**National University of Water Management and Nature Resources Use, Rovno, Ukraine
Keywords: heat transfer, condensation, smooth tube, horizontal tube, refrigerant
Abstract: This paper presents the analysis of the study on in-tube condensation performed until 2010. It is found that in all published studies only tubes with average perimeter and heat transfer coefficients at certain length (minimum 0,5 m) during condensation inside smooth tubes have been measured that did not provide sufficient data concerning the features of heat transfer during condensation, namely impact of vapour quality, vapour velocity, heat flax, condensate accumulation on heat transfer. The disadvantages of the existing methods of heat transfer research, of experimental data presentation, and of design correlations are pointed out.
e-mail: sadykov_r_a@mail.ru
Kazan State University of Architecture and Engineering
Keywords: mathematical model, heat and mass transfer, protecting design, filtration, moisture content, thermal stream, evaporation, condensation, air penetration
Abstract: General mathematical model (MM) of the stationary non-linear molecular transfer of heat and moisture through shielding constructions (SCs) with consideration of infiltration and ex-filtration of vapor-air mixture in the presence of internal heat drainages or heat sources(HSs) is offered for various canonical forms (the plane, the cylinder, a sphere, etc.). Mathematical formalization of one-dimensional transfer problem and its general solution are presented. On the basis of this general solution and under given set of various uniqueness conditions, solutions of concrete diverse physical processes with constant or variable thermo-physical characteristics and heat sources are constructed and analyzed.
e-mail: oleg-ili@yandex.ru
Kazan State Power Engineering University
Keywords: water quality, conductometry, chemical water treatment, electrolytic conduction, contactless two-channel conductometric transducer
Abstract: The brief survey of the existing delivery and feed water control methods was given. The principal scheme and contactless, two-channel conductometric transducer principle of operation were given. The construction and contactless two-channel conductometric transducer method for continuous quality control of delivery water in water and heat supply networks were developed and proposed for the further discussion. The dependence of output signal on supply network frequency was obtained. The frequency range of a low-frequency generator was calculated. It provides maximum output signal for solutions containing the following salts: NaCl,CaCl2,MgSO4,KCl and also for BBF -210/140 bend-tube boiler feed water.
e-mail: nataboi@ya.ru
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Keywords: crack growth rate, creep, fatigue, material properties
Abstract: The method for creep crack growth rate determination is described. This method covers the determination of creep crack growth properties of nominally homogeneous materials with the use of pre-cracked compact type (CT) test specimen subjected to uniaxial cyclic forces.
e-mail: chboyadj@bas.bg
Bulgarian Academy of Sciences, Institute of Chemical Engineering
Keywords: model parameters identification, incorrect inverse problem, iterative method regularization
Abstract: A method for model parameters identification as an incorrect inverse problem solution has been proposed. An iterative regularization procedure and numerical algorithm has been developed.
e-mail: demidov@hitv.ru
Kazan State Power Engineering University
Keywords: radon, progeny, polonium, radioactivity, detection, human safety, radon monitors, lung cancer.
Abstract: The article deals with key physical methods of today’s methods on radon detection and risk assessment. Principles of operation of modern radon monitors are reviewed and explained. Methods of radon detection in air, soil and water are reviewed along with actual examples of the measurements carried out in the area of Kazan.
e-mail: G.Barakos@Liverpool.ac.uk , nikjhon@mail.ru
*CFD Laboratory, University of Liverpool, Liverpool, L69 3GH, UK,**Kazan National Research Technical University n.a. A.N. Tupolev
Keywords: rotor in hover, wake geometry, blade loading, structured multi-block mesh, caradonna and tung rotors, tip vortex.
Abstract: Accurate prediction of rotor loads and wake geometry is a challenging problem in theoretical aerodynamics and essential for the design of rotors with good performance. The capability of CFD solver to accurately capture the wake trails behind the rotor usually associated with mesh resolution used to reduce artificial dissipation raised due to numerical discretization especially in the wake region that can cause the wake dissipate and disperse earlier on a coarse mesh. A suitable mesh resolution and topology is then required to preserve the rotor wake. This paper presents detail validation results of rotors performance and its wake geometry in hover and vertical climb, obtained using a structured, multi-block, computational fluid dynamic (CFD) method based on Reynolds-averaged Navier-Stokes with third-order spatial accuracy for a range of rotor tip speed and collective pitch settings. For wake investigation, wake trajectories and strength were captured and analysed. The predicted data were then compared with available experimental data and the results indicates that, blade loading and wake geometry are in excellent agreement with experiments and have moderate sensitivity to the grid resolution used.
EFFICIENCY OF ANAEROBIC FERMENTATION UNDER VARIOUS TYPES OF HYDRAULIC MIXING
I.A. Trakhunova
e-mail: irseen2@yahoo.com
Keywords: Biogas, hydraulic agitation, intensity
Abstract: There are various mixing methods used in biogas production. The hydraulic agitation method realized by circulating supply of organic substrate is considered in this work. The preference of inlet pipes location choice is based on the best substrate mixing and prevention of the crust formation on the surface. The mathematical model describing the process of hydraulic mixing in a reactor is obtained. Based on numerical calculations the comparative analysis of the intensification of the process of anaerobic digestion for different modes and locations of input and output pipes was conducted.