[en] Use of empirical models is described in the prediction of acoustic noise generated by turbulent flow and the induced vibration at the location of a sensitive element. The principle of the models and the result of their application are presented

[en] Creating optimal vibro systems requires sequential solving of a few problems: selecting the basic pattern of dynamic actions, synthesizing the dynamic active systems, optimizing technological, technical, economic and design parameters. This approach is illustrated by an example of a high-efficiency vibro system synthesized for forming building structure components. When using only one single source to excite oscillations, resonance oscillations are imparted to the product to be formed in the horizontal and vertical planes. In order to obtain versatile and dynamically optimized parameters, a factor is introduced into the differential equations of the motion, accounting for the relationship between the parameters, which determine the frequency characteristics of the system and the parameter variation range. This results in obtaining non-sophisticated mathematical models of the system under investigation, convenient for optimization and for engineering design and calculations as well

[en] The subject of the present work is the parametrical investigation of hydrodynamic and thermal characteristics of laminar flow with phase-change in a heating microchannels. The study is based on the quasi-one-dimensional model of non-isothermal capillary flow. This model takes into account the evolution of flow, heating and evaporation of the liquid, as well as the influence of capillary, inertia, friction and gravity forces. The effect of various parameters (sizes of microchannel, initial temperature of cooling liquid, wall heat flux etc.) on hydrodynamic and thermal structures of the flow, the length of heating, evaporation and superheat regions is studied. Thc specific features of the phenomena is discussed

[en] This study involves the transport or stirring properties of viscous vortex rings. In order to take into account the Reynolds - number dependence, the method of entrainment diagrams is applied. The system for path lines of fluid particles is developed with the help of obtained analytical solution for a vortex ring. The idea of such approach is based on the property of this dynamical system to include complicated Reynolds - number dependence despite the fact that the linear solution of Navier-Stokes equations is used. Unsteady particle trajectories are examined as a bifurcation of an autonomous system with the initial Reynolds number as a parameter. It is shown that for small ratio of external and internal radiuses of the ring, three regimes of particle motion exist and the pattern bifurcates at a two Reynolds numbers of 140 and 640

[en] The Hamiltonian formalism for the motion of a deformable body in an inviscid irrotational fluid is generalized for the case of the motion in a bounded fluid. We found that the presence of the boundaries in a liquid leads to the chaotization of the body's motion. The ('memory' effect connected with a free surface boundary condition is also accounted for

[en] Re powering faith gas turbine means integration of new gas turbine in existing power plant. Such integration yield higher efficiencies lower operating and maintenance costs and reduction in pollution emission. This paper summarizes the results of a feasibility study that inquired the possibilities of such integration in Israel Electric Corporation - IEC's existing steam power plants (oil fired)

[en] Linear and nonlinear stability of the flow between coaxial cylinders is investigated. The linear analysis is carried out within scope of temporal linear stability theory. The eigenvalue map is obtained with the collocation method based on Chebyshev polynomials. The nonlinear analysis is based on a novel parallel code for DNS of a coaxial pipe flow. It is shown that the major source of finite amplitude instability is associated with the interaction of three-dimensional disturbances and stream wise rolls

[en] The paper presents a general concept of a hybrid propulsion system, based on an SI internal combustion engine fueled by methanol dissociation products (MDP). The proposed hybrid propulsion scheme is a series hybrid, which allows the engine to be operated in an on-off mode at constant optimal regime. The engine is fed by gaseous products of methanol dissociation (mainly hydrogen and carbon monoxide) emerging from an on-board catalytic reformer. The general scheme and base operation features of the propulsion system are described. The benefits that may be achieved by combining the well-known idea of on-board methanol dissociation with the hybrid vehicle concept are discussed. The proposed scheme is compared with those of systems operating on gasoline, liquid methanol, hydrogen and also with the multi-regime (not hybrid) engine fed by MDP

[en] Mechanical engineering has various disciplines. The book of proceedings contains presentations works done in some of these disciplines

[en] The concept of dynamic stability of elastic structures subjected to sudden (step) loads is discussed. The various criteria and related methodologies for estimating critical conditions are presented with the emphasis on their similarities and differences. These are demonstrated by employing a simple mechanical model. Several structural configurations are analyzed, for demonstration purposes, with the intention of comparing critical dynamic loads to critical static loads. These configurations include shallow arches and shallow spherical caps, two bar frames, and imperfect cylindrical shells of metallic as well as laminated composite construction. In the demonstration examples, the effect of static pre loading on the dynamic critical load is presented