ISSN 1991-2927
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## Author: "Ruslan Vladimirovich Fedorov"

 V. Kovalnogov, R. Fedorov, L. Khakhaleva, A. Chukalin
 Mathematical Modeling and Numerical Analysis of Thermal Protection Effectiveness With Hemispherical Damping Cavities The gas turbine engine performance improvement is linked inextricably with the increase of the intensity of dynamic, aeromechanical and thermal processes, which, in turn, requires the development of systems and devices allowing to protect the most loaded equipment components. The most effective ways to protect surfaces from overheating are a convective cooling; the absorption and accumulation of heat by condensed substances; the cooling that operates on mass transfer principle; the radiation and electromagnetic cooling; heat-shielding coatings. One of the most effective ways to protect surfaces from overheating is a thermal protection in the form of film-like surface cooling based on the mass-transfer surface-cooling principle. This method is widely distributed and it proved to be effective. The paper considers the possibility of improving this method of cooling due to the impact on the boundary layer with hemispherical damping cavities behind the injection section of the cooler. A mathematical model is proposed, the numerical study of the thermal protection effectiveness by the use of hemispherical damping cavities is carried out. The possibility of a significant decrease of the turbulent heat exchange in the boundary layer and of the efficiency improvement of the thermal surface protection of ? by0.06 due to the use of hemispherical damping cavities has been established. The proposed method of thermal protection intensifying and numerical analysis of its efficiency will improve the gas turbine engines that are available for different applications of domestic industry for example in power generation sector, aircraft engineering as well as in shipbuilding.Hemispherical damping cavities, turbulent transport, mathematical modeling, boundary layer, thermal protection.
 2018_ 4

Sections: Mathematical modeling

Subjects: Mathematical modeling.

 V. Kovalnogov, D. Generalov, A. Chukalin, R. Fedorov, A. Plekhanova
 New Engineering Solutions Based on Mathematical Modelling of the Turbine Blade System The article deals with a method for studying the thermal state of turbomachine blades and a numerical investigation method taking into account the phenomenon of gas-dynamic temperature stratification. The authors consider the possibility of increasing the efficiency of cooling turbine blades due to the phenomenon of gas-dynamic temperature stratification, the possibility of improving the accuracy of the calculated forecasting of the thermal state of the blades by obtaining reliable data by developing a mathematical model and a unique software and information complex for modelling.Mathematical modelling, numerical methods, thermal protection, film cooling, software and information complex, dispersed flow.
 2017_ 3

Sections: Mathematical modeling

Subjects: Mathematical modeling.

 V. Kovalnogov, A. Chukalin, L. Khakhaleva, R. Fedorov, A. Plekhanova
 Researching the Influence of the Number of Damping Cavities on Frictional Resistance of Turbulent Flow As a result of experimental and numerical research of turbulent flow with effects on the basis of the modified model of the Prandtl mixing length with the use of pressure pulsation analysis, the structure and resistance of turbulent flow frictional resistance were calculated. The developed model of turbulent exchange and the calculation method allow to take adequately into account the features of the metabolic processes in the presence of damping cavities and predict the frictional resistance with the help of preliminary calculation. The possibility of reduction of the frictional resistance coefficient of a turbulent flow to 35 % was experimentally set with the use of damping cavities. The generalization of the influence of the amount of damping cavities on the frictional resistance was carried out.Damping cavities, mathematical modelling, frictional resistance, turbulent flow.
 2017_ 1

Sections: Mathematical modeling

Subjects: Mathematical modeling.

 V. Kovalnogov, R. Fedorov, L. Khakhaleva, A. Chukalin
 Mathematical Modeling and Numerical Analysis of Flow Laminarization in a Perforated Tube With Damping Cavities The authors have experimentally established the possibility of the partial turbulent flow laminarization in a perforated tube with damping cavities which leads to reduction of up to 35% of frictional resistance. The effect of the number of perforations in the damping cavity on the velocity profile and the frictional resistance has been revealed. The model of turbulent transfer in a boundary layer near the perforated surface with damping cavities and the method of calculating the flow pattern and frictional resistance were proposed. Flow laminarization manifested itself as the decrease of turbulent transfer intensity in the boundary layer due to external or internal influences plays an important role in engineering. Apparently, for the first time the possibility of a reverse transition of a turbulent flow in a laminarization one under the influence of a negative longitudinal pressure gradient was noted in the article [1]. Further researches overviewed in the paper [2] have demonstrated that laminarization in flows with negative longitudinal pressure gradient is accompanied by a substantial (up to 35 ... 50%) decrease of the intensity of heat and a simultaneous increase in the frictional resistance. The model of laminarization in the streams with different influences proposed in the paper [2] has allowed to predict the possibility of its implementation and anear perforated surface with damping cavities. As this takes place, in contrast to the laminarization under the influence of a negative longitudinal pressure gradient there must be a reduction of both the intensity of heat transfer and friction resistance. The purposes of this work are experimental investigation of frictional resistance in the perforated tube with damping cavities with a different number of perforations, the development of turbulent transfer process models and the calculation method of friction resistance.Perforated pipe, a damping cavity, turbulent transfer, mathematical modeling, friction resistance.
 2015_ 4

Sections: Mathematical modeling

Subjects: Mathematical modeling.

 R. Fedorov, D. Generalov, M. Kornilova
 Mathematical Modeling and Numerical Analysis of a Thermal State of Turbo-mashine Blades Affected By a Supersonic Dispersed Flow The development of the advanced gas-turbines must ensure their operation under the conditions of an increasing temperature of a working body to improve the efficiency during in a reliable and efficient operation. In this paper, a mathematical model and a method of a numerical research of a thermal state of turbo-machine blades affected by a supersonic dispersed flow including a gas-dynamic temperature stratification phenomenon are introduced. The adequacy of a turbulent dispersed boundary layer model was verified by comparing the calculation of the heat transfer coefficients of the dispersed flow in the nozzles with the experimental data. In order to improve the accuracy of the calculated prediction of the thermal state of the blades due to obtaining the reliable data, as well as the efficiency of cooling systems for the increasing resource of the blades, a software and information complex integrated into the Solid Works package is currently being developed on the base of the Turbo Works package at the Department of Heat Power Engineering of Ulyanovsk State Technical University. The research results of the temperature stratification will be included into this software and information complex as a unique information base. As the analysis of the numerical study results shows, the application of the developed convective-film cooling temperature provides the temperature reduction to the trailing edge of the turbo machine blade by 1.6 times compared with the convection cooling.Mathematical modeling, numerical methods, thermal protection, convective-film cooling, software and information complex, dispersed flow.
 2014_ 4

Sections: Mathematical modeling

Subjects: Mathematical modeling.

 V. Kovalnogov, R. Fedorov, E. Tcvetova, A. Petrov
 Mathematical Modeling and Investigation of Effectiveness of Gas-dynamic Temperature Stratification in Disperse Flow The article gives a method and results of a numerical investigation of the process of gas-dynamic temperature stratification in disperse flow. It justifies an opportunity to significantly increase the efficiency of temperature stratification of dispersed flow via heat transfer surface enhancers made on the working surface of the subsonic flow path.Gas-dynamic temperature stratification, disperse flow, supersonic flow, heat transfer enhancement.
 2013_ 1

Sections: Mathematical modeling, calculi of approximations and software systems

Subjects: Mathematical modeling.

 V. Kovalnogov, A. Korolev, R. Fedorov
 Mathematical Modeling and Numerical Analysis of Efficiency of Surface Film Coolingin Supersonic Flow Dispersion The article provides a mathematical model and results of computational investigations into the effect of the inertial deposition of particles of condensed phase on the efficiency of film cooling of surface in supersonic flow dispersion. The authors determine a possible realization of Leontyev paradox in adiabatic surface area, which consists in achieving protected surface temperature less than that of cooler in permeable area of protection creation.Boundary layer, thermal protection, mist flow, modeling.
 2012_ 4

Sections: Mathematical modeling, calculi of approximations and software systems

Subjects: Mathematical modeling.

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