A. V. Luikov Heat And Mass Transfer Institute

Minsk, Belarus

A. V. Luikov Heat And Mass Transfer Institute

Minsk, Belarus
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Kot V.A.,A. V. Luikov Heat And Mass Transfer Institute
Journal of Engineering Physics and Thermophysics | Year: 2017

The boundary function method is proposed for solving applied problems of mathematical physics in the region defined by a partial differential equation of the general form involving constant or variable coefficients with a Dirichlet, Neumann, or Robin boundary condition. In this method, the desired function is defined by a power polynomial, and a boundary function represented in the form of the desired function or its derivative at one of the boundary points is introduced. Different sequences of boundary equations have been set up with the use of differential operators. Systems of linear algebraic equations constructed on the basis of these sequences allow one to determine the coefficients of a power polynomial. Constitutive equations have been derived for initial boundary-value problems of all the main types. With these equations, an initial boundary-value problem is transformed into the Cauchy problem for the boundary function. The determination of the boundary function by its derivative with respect to the time coordinate completes the solution of the problem. © 2017 Springer Science+Business Media New York

Fomin N.A.,A. V. Luikov Heat And Mass Transfer Institute
Journal of Engineering Physics and Thermophysics | Year: 2017

“Shock waves are of special interest from a whole number of aspects. On the one hand, where attempts at integrating equations without introducing discontinuities (i.e., shock waves) lead to these or those paradoxes and to the impossibility of solving these equations, the shock wave theory resolves paradoxes and permits creating regimes of motion under any conditions. One the other hand, shock waves themselves are a paradoxical event. They are paradoxical in the sense that without making any assumptions about dissipative forces — about viscosity and heat conduction — we obtain, from elementary considerations, laws, according to which there is an increase in entropy, i.e., laws, according to which the processes proceeding in the shock wave are irreversible.” Ya. B. Zel’dovich, 1946 © 2017 Springer Science+Business Media, LLC

Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2011.6.1 | Award Amount: 4.66M | Year: 2012

SmartHG will develop economically viable Intelligent Automation Software services gathering real-time data about energy usage from residential homes and exploiting such data for intelligent automation pursuing two main goals: minimise energy usage and cost for each home, support the Distribution Network Operator (DNO) in optimising operation of the grid. SmartHG rests on the following four pillars.\n\nFirst, Internet-based open standard protocols enabling effective communication between: i) home devices (e.g., sensors, smart appliances, local generators, electric vehicles, energy storage) and SmartHG services; ii) SmartHG services and DNO software systems; iii) any pair of SmartHG services. This will enable development of hardware device-independent energy services, possibly on the basis of the services already available.\n\nSecond, user-aware SmartHG services focusing on residential homes. Such services will measure home energy usage and local generation (e.g., from renewable sources), forecast it and actuate home devices (both loads and generators) in order to minimise the home energy bill and usage (local optimisation) with respect to a given price policy computed to attain global (grid level) optimisation.\n\nThird, demand-side aware SmartHG services focusing on the grid. Such services will compute individual (yet fair) price policies for each single home taking into account user preferences while optimizing grid operations. Grid safety for such price policies will be formally verified using model-checking-based techniques. Furthermore, such SmartHG services will increase grid reliability by estimating and controlling (using price policies) voltages and currents in internal unmonitored nodes of the grid.\n\nFourth, SmartHG case studies in Kalundborg and Minsk will enable thorough technical, environmental and economical evaluation of project results.\n\nFinally, SmartHG consortium consists of three highly qualified and multidisciplinary clusters comprising: four research institutions focusing on Computer and Electrical Engineering, four Energy Service SMEs, two DNOs and a municipality. The resulting synergies will ensure the success of the project as well as the wide dissemination and the effective exploitation of the project results.

Zhdanov V.,University of Rostock | Chorny A.,A. V. Luikov Heat And Mass Transfer Institute
International Journal of Heat and Mass Transfer | Year: 2011

Simultaneous development of macro- and micromixing in confined axis-symmetric reacting flows has been determined experimentally. Mixing of aqueous solutions of acid (internal jet) and base (coflow) with the coflow-to-jet flow rate ratio Q=V̇c/V̇j=5.0, at which the velocity at the jet exit was higher than the co-flow one, was examined in a co-axial jet mixer. The two-color PLIF method was used: the dyes - sodium fluorescein and rhodamin B - were premixed to the jet. The reaction product concentration or molecular mixing was determined by measuring the radiated light intensity of sodium fluorescein. The fluorescence of rhodamin B highlighted turbulent transfer by vortices or mixture fraction development. Variations of reactant concentrations were calculated using the mass conservation equation and the simultaneously measured distributions of mixture fraction and chemical reaction product concentration. The analysis of mixing parameters showed a significant difference in the dynamics of turbulent and molecular mixing. © 2010 Elsevier Ltd. All rights reserved.

Vasiliev L.L.,A. V. Luikov Heat And Mass Transfer Institute | Kanonchik L.E.,A. V. Luikov Heat And Mass Transfer Institute
Chemical Engineering Science | Year: 2010

To obtain high hydrogen sorption capacity and reduce the time of the cycle (adsorption/desorption) in the gas storage system a new composite material (metal hydride particles on the activated carbon fibre matrix) was suggested. Different adsorbent materials such as activated carbon fibre "Busofit", granular activated carbon and new composite sorbent (metal hydride La 0.5Ni 5Ce 0.5 particles on the activated carbon fibre "Busofit") were tested. Effect of the carbon sorbent nature and metal hydride content is important to choose the optimal sorbent bed. In this paper, a thermally regulated storage system for hydrogen was numerically analyzed and experimentally validated. A two-dimensional transient model was used to analyze the influence of the thermal control on the operating characteristics of the flat sectional vessel. The evolution of the temperature, pressure and volumetric density of hydrogen inside the vessel during the charging/discharging is discussed. It was shown that heat pipe based thermal control of the process increase the efficiency of the hydrogen storage. Such vessels are interesting to be applied in fuel cells used for vehicle or dual-fuel engine car (hydrogen/gasoline, hydrogen/methane). © 2009 Elsevier Ltd. All rights reserved.

Sychevskii V.A.,A. V. Luikov Heat And Mass Transfer Institute
International Journal of Heat and Mass Transfer | Year: 2015

In the present work we show that in drying of colloidal capillary-porous materials the processes of heat and mass transfer are usually accompanied by the processes of deformation and development of stresses. Application of the Euler approach, which is connected only with the account of small deformations, to description of the occurring processes is erroneous. The stressed-strained state should be described on the basis of the Lagrange approach with account for large displacements and deformations of material. In this connection, we present a physical-mathematical model of the process of drying colloidal capillary-porous materials in curvilinear coordinates in the tensor form. A variational formulation of the problem and its solution by the method of finite elements are presented. The results of calculations and regularities obtained on their bases are given. Special attention is paid to the fact that the developed model and calculation techniques can form a theoretical basis for designing devices of experimental determination of stresses in materials. © 2015 Elsevier Ltd. All rights reserved.

Kashevsky S.B.,A. V. Luikov Heat And Mass Transfer Institute
Computational Materials Science | Year: 2010

This paper presents computational studies of the dissipative self-organization of a system of soft magnetic particles in a drying thin layer of polymer solution set under a rotating magnetic field. The structure transformations during the layer drying is modeled for different situations including constant/increasing viscosity, regard/disregard of the hydrodynamic interactions, slow or fast drying with respect to the structure formation. All these factors are found influential on the final pattern of the particles distribution in the settled polymer film. © 2010 Elsevier B.V. All rights reserved.

Kot V.A.,A. V. Luikov Heat And Mass Transfer Institute
Heat Transfer Research | Year: 2016

Results of a numerical analysis of the integral method of boundary characteristics (IMBCh) formulated in the generalized system of coordinates with the Dirichlet condition are presented. It is shown by the example of a number of test problems that, as regards the accuracy and convergence of approximate solutions, this method exceeds by an order or several orders of magnitude the known methods based on the consideration of the disturbance front. An analysis of the accuracy of approximation and convergence of solutions showed that the solutions constructed be means of this method are exact, since an error for a wide range of values of the problem parameters amounts to hundreds-Tens of thousands percent. © 2016 by Begell House, Inc.

Kalitko V.A.,A. V. Luikov Heat And Mass Transfer Institute
Journal of Engineering Physics and Thermophysics | Year: 2010

On the basis of experience in the commercial operation of tire-shred steam thermolysis in EnresTec Inc. (Taiwan) producing high-grade commercial carbon, liquid pyrolysis fuel, and accompanying fuel gas by this method, we have proposed a number of engineering solutions and calculated-analytical substantiations for modernization and intensification of the process by afterburning the accompanying gas with waste steam condensable in the scrubber of water gas cleaning of afterburning products. The condensate is completely freed of the organic pyrolysis impurities and the necessity of separating it from the liquid fuel, as is the case with the active process, is excluded. © 2010 Springer Science+Business Media, Inc.

Khramtsov P.P.,A. V. Luikov Heat And Mass Transfer Institute | Penyazkov O.G.,A. V. Luikov Heat And Mass Transfer Institute | Shatan I.N.,A. V. Luikov Heat And Mass Transfer Institute
Experiments in Fluids | Year: 2015

The paper discusses the principles of optical testing of transparent objects using the Talbot images method and its applicability to diagnostic of flames. The experimental study was performed for premixed methane–air flame formed by an axisymmetric nozzle. The local deflection angles of the probe radiation were determined from measurements of the relative displacements of intensity maxima of the Talbot image which is caused by passing of light through the flame. The Abel integral equation was solved to reconstruct the refractive index distribution in the flame. Calculation of the temperature field from the refractive index data was based on neglecting the spatial variation of the component composition. Inaccuracy of the calculations was evaluated by comparing the results with the thermocouple measurements. The results demonstrate that the Talbot images method can be used to measure the temperature distribution in axisymmetric reacting gas flows with high spatial resolution. © 2015, Springer-Verlag Berlin Heidelberg.