Influence Of Wave Processes Research Articles

СИСТЕМА АВТОМАТИЧНОГО КЕРУВАННЯ ГІДРОТРАНСПОРТНОЮ СИСТЕМОЮ ЗІ СТАБІЛІЗАЦІЄЮ ТИСКУ

Purpose. The work is devoted to the development of a closed-loop control system of hydraulic transport system with pressure stabilization and its research on a mathematical model. Originality. The expediency of application of a closed-loop control system of electric water transport system with pressure stabilization as the most promising way of resource saving in the operation of pumping complexes is substantiated. The realization of the closed-loop pressure stabilization system using a discrete program regulator is proposed. The studies of parametric sensitivity of the closedloop pressure stabilization system have confirmed the high robustness of the proposed solution. Methodology. General methods of physics, hydraulics, mathematical analysis and computational mathematics were used to solve the tasks. Numerical solution of mathematical model equations and visualization of obtained results were performed in MATLAB®/Simulink environment. Results. The expediency of using closed-loop control systems of pumping units with pressure stabilization as the most promising way of resource saving in the operation of pumping complexes is substantiated. The impossibility of implementing the pressure stabilization system based on the classical PID controller is shown, which is caused by the influence of wave processes in the pipeline system with distributed parameters. The closed-loop pressure stabilization system with the use of a discrete program regulator is realized, its stability and robustness in a wide range of changes in the regulator parameters is shown. Practical value. The possibility of implementing a closed-loop pressure stabilization system of electric hydrotransport system has been substantiated; a method of calculating the discrete program pressure regulator based on the regression analysis of the results of mathematical modeling has been proposed. Figures 12, tables 2, references 9.

The influence of wave processes on the reinforcement of the base plate of a ballast-free railway track

Introduction. Since nowadays ballast-free track structures are most often used in combination with continuous welded track solutions for organizing a rail string, it should be emphasized that stresses arising in the rail string affect the stress-strain state of the entire construction of the track superstructure; therefore, it is necessary to monitor the current state of the continuous welded track. Nevertheless, kinks are formed and assembled rails and sleepers lose stability during the operational period of a continuous welded track, and methods are needed to determine the pre-failure conditions related to the temperature range of operation of a continuous track. Materials and methods. In this study, we propose a model of a flat structure made of a material having anisotropic properties, which makes it possible to take account of initiation and propagation of wave processes under the action of an external dynamic load. Results. The considered methods of simulating the propagation of elastic waves in a plate will make it possible to identify the points where direct and reflected waves of various orders converge; these waves can both increase and reduce the overall intensity of wave processes, leading to an increase or reduction in stresses and deformations in the characteristic points of a structure. Conclusions. The proposed solutions are most relevant for the structural elements of transport infrastructure facilities, since they are the ones that are exposed to alternating dynamic loads having varying intensity and time distribution of characteristic values.

The influence of wave processes on the sample deformation mechanism

The process of plastic waves propagation in a sample based on the deformation theory of plasticity is considered. The research results of the stress shock waves propagation in a sample are considered. The mechanical properties of the samples under dynamic loading are studied on the basis of the propagation theory of deformation and stress waves. The process kinematics of the sample dynamic deformation is studied.

Mathematical modeling of wave processes and transport of bottom materials in coastal water areas taking into account coastal structures

The necessity of numerical modeling of the mechanisms of formation of the field of suspension and sediment flow determines the urgency of the problem under study. The process of developing shallow coastal zones, with constructive transformation and changes in coastal reliefs, is becoming increasingly important. Assessment of the hydrodynamic impact on shore protection structures and coastal structures installed at the bottom of a shallow water body is an important task at present. With a constructive transformation of the reliefs, one should take into account the dynamics of the formation of the coast investigate the formation of the profile of the bottom in the coastal zone of the reservoir under the influence of wave processes. For determining the dynamics and trend of phenomena occurring in the coastal waters and predicting possible interventions in the ecosystem, the need to build mathematical models of the transport processes of matter in the coastal waters, taking into account the presence of coastal structures, is actualized.

Influence of wave processes on stratified currents in a bay

We present the results from studying the system of currents with wind-driven circulation and density flow observed in Petrozavodsk Bay of Lake Onega. The origin of the currents is shown to be related to surface and internal waves. It is found that the evolution of the current velocity field is determined by variations in the levels of the water’s surface and the thermocline, the profile of exchange factor, and the disturbances in velocity in the area of its sign change with depth. A mathematical model of the system of currents is developed.

Analysis of pipeline fracture by fast crack propagation

An analysis is presented of the influence of wave processes in gases and in a pipeline wall on extended fracture by fast crack propagation. The influence of design and technological parameters of the pipeline and of the pipe metal fracture toughness on the extent of fracture is shown.

Influence of wave processes on hydrodynamics of flows in absorption and distillation vessels

Influence of wave processes on hydrodynamics of flows in absorption and distillation vessels