Biography
Anna Kapranova is the Head of Department of Theoretical Mechanics and Strength of Materials at Yaroslavl State Technical University, Yaroslavl, Russia.
Abstract
Statement of the Problem: The efficiency of the control equipment for the transportation of fluid flows depends on the degree of protection of the valve from the undesirable effects of cavitation phenomenon. Th e study of the formation of cavitation bubbles at the initial stage of hydrodynamic cavitation in a fl owing part of the control valve allows identify from a set of its constructive regime parameters to identify the main factors influencing the evolution of bubbles. Despite the existence of various deterministic and stochastic descriptions of this process, the modeling problem is relevant. Th e purpose of this study is to determine the integral characteristics of the process of formation of cavitation bubbles when operating the control valve. Methodology & Theoretical Orientation: On the basis of the stochastic approach, the model of formation of cavitation bubbles proposed by the authors is used. Th e application of the formalism of process Ornstein-Uhlenbeck with the description of stochastic energy of a spherical bubble depending on its radius and the velocity of the center of mass allows using the differential distribution function of the cavitation bubbles according to their sizes for the estimation of the integral characteristics of the process. Findings: Th e simulation results allow to evaluate average values for the radius of the cavitation bubble, surface area of bubble and to estimate the volume of a cavity in the initial stage of hydrodynamic cavitation, depending on constructive-regime parameters of fl ow area control valve. Conclusion & Signifi cance: Modeling the initial stage hydrodynamic cavitation can be performed from the positions of the stationary and homogeneous Markov process. The results obtained here can be used in the formation of methods of engineering calculations of control valves.
Biography
Anna Kapranova is the Head of Department of Theoretical Mechanics and Strength of Materials at Yaroslavl State Technical University, Yaroslavl, Russia.
Abstract
Statement of the Problem: Th e process of mixing of bulk components is one of the main stages of their processing. Obtaining quality mixtures of bulk materials with unequal content of their volume fractions is actual problem for a variety of industries. Portion method of mixing of bulk components can be successfully implemented in the apparatus of gravity type using the additional mixing drums with a spiral coiling of brush elements. Th e study of mechanics of behavior of the rarefied flows of mixed materials in the working volume of the device of gravity type can be performed on the basis of stochastic approach. Th e purpose of this study is the research of the volume fraction of key component in the second phase of the portion mixing by means of the device of gravity type. Methodology & Theoretical Orientation: On the basis of the stochastic approach, the model of spreading of particles of bulk materials aft er interaction with brush elements is proposed as well as method of evaluating the volume fraction of a key component after the shock dispersion of the bulk components at the initial stage of batch mix. Findings: Th e results of stochastic modeling in the form of sets of non-equilibrium distribution functions for the number of particles of each of the granular material depending on the corners of their spreading aft er impact on inclined fl at bump-stop allow revealing the conditions for obtaining the most homogeneous mixture at the second stage of the batch mixing. Conclusion & Significance: Th e results obtained depend on constructive-regime parameters of apparatus of gravity type,physicomechanical properties of mixed materials. Results could be used as the basis for development of an evaluation method for the degree of homogeneity of the granular mixture in the engineering method of calculation of specified device parameters.