The method for numerical simulation of measuring the concentration of particles of two types in a liquid-based on Rayleigh scattering during their deposition is proposed. The mathematical model takes into account the forces of gravity, hydrostatic lifting force, forces of resistance to motion. Additionally, the contribution of the influence of Brownian liquid motion on the movement of suspended particles was taken into account. The magnitude of the scattering of the light flux as it passes through the volume of liquid with particles suspended in it is modeled. A numerical calculation was carried out according to the developed mathematical model.
The paper discusses approaches to the numerical integration of the second-kind Manakov equation system. Emphasis is placed on the transition from writing equations in dimensional quantities to equations in dimensionless units. A combined explicit-implicit finite-difference integration scheme based on the implicit Crank- Nicolson finite-difference scheme is proposed and substantiated, which allows integrating a non-linear system of equations with a choice of non-linear term at the previous integration step. An algorithm for leveling the disadvantage associated with the definition of the nonlinear term from the previous integration step is proposed. The approach of automatic selection of the integration step, which reduces the total number of integration steps while maintaining the required accuracy of the approximate solution, is substantiated. Examples of the calculation results for some values of the disturbance propagation are given. The limitations imposed by the scheme on the length of the integrable fiber section are described, and approaches are proposed that eliminate these limitations without the need to increase the dimensions of the finite-difference scheme arrays. Requirements for initial boundary conditions were discussed.
The article is about gas air stream modeling at a nozzle cross section of a turbomachine for steady and unsteady operating mode, the mathematical model is assigned, which describes acoustic processes in a turbomachine flow path and the ways of their improvement. The principles of aero-acoustic cartography complex systems creation are defined by means of acouto-electronic and they are accompanied by methods and means of gas dynamic stream parameter measurement in the flow path and at nozzle cross section of a turbomachine. The principles described make the control more informative and ease the algorithm creation for nondestructive method of rotor blade condition monitoring. Altogether it provides reliable data in conditions of gas air stream parametric and structural uncertainty both in controlled inside section of the flow path and in outlet section at a turbomachine cut. The tasks of monitoring point placement and the tasks of a field spatial distribution reconstruction are reviewed according to measurements in a discrete set of points separately. In complex approach the turbomachine acoustic field reconstruction is realized according to measurement data of optical fiber sensor outlet using the statistical approach only. The field reconstruction in 1D, 2D and 3D formats is presented as continuous functions of spatial coordinates according to measurements in a discrete set of points where a priori information about the field features is available.
In this article, the advantages of the unity of sensory and telecommunication approaches will be shown, using examples of monitoring systems for second-generation telecommunication passive optical networks (PON). In comparison with the TDM network architecture, its combination with the WDM architecture is much more efficient, both in terms of the number of channels per fiber, and in terms of the number of channels per laser. This architecture showed a high coverage of monitoring objects by sensors in optically efficient network organization with their small number. Theoretically, the number of sensors in the fiber optical sensor system (FOSS) can be expanded to 256 sensors using two fibers. Note that in the fiber optical telecommunication system (FOTS) the maintenance of 256 PON TDM-WDM terminals is a typical requirement. Thus, monitoring tasks for FOTS and FOSS PON are based on unified approaches. In general, when designing a FOTS, it is necessary to take into account the close relationship that exists between all the factors that determine the characteristics of the network elements, with the existing economic conditions, which will create an optimal network.
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