Methods of reduction of interference signals in electromagnetic conductors that measure fluid flow

The pressure in the fluid flow, especially in the pipes of closed water supply systems, is generated mainly by pumps, and the water flow is usually pulsating. Electromagnetic transducers used to measure such nonstationary and pulsating fluid flow rates must have low inertia and high dynamic accuracy. In such cases, the frequency characteristics of electromagnetic transducers that measure fluid flow are their main parameters. It should be noted that the performance of the converters used to measure the flow rate of pulsating fluids should not depend on the change in the distribution profile of the flow velocities, otherwise additional measurement errors will occur. It is used in measuring non-stationary and pulsating fluid flow rates in controlled and controlled technological processes.

Pulsing Flows of a Viscous Incompressible Liquid in a Pipe with Elastic Walls

As you know, the recent intensive introduction into practice of flexible pipelines made of polymer synthetic materials, pulsating fluid flow in elastic pipes is of great importance. As you know, the recent intensive introduction into practice of flexible pipelines made of polymer synthetic materials, pulsating fluid flow in elastic pipes is of great importance. By solving the problem, the necessary hydrodynamic parameters will be determined, such as pressure distributions, velocities, flow rates, the speed of propagation of the pulse wave pressure and their decay. For the first time in this article, a decrease in hydraulic resistance in a pulsating flow through pipes due to the elasticity of the wall will be determined. The dependence of the dimensionless value of the pressure pulse wave on the vibrational number was investigated .The speed of the pulse wave was compared with the speed of Moens-Korteweg , and significant differences were revealed between them occurring at lower values of the Womersley oscillatory parameter, at large values of which significant differences are not observed. The dependence of the reciprocal damping per wavelength on the vibrational number , was also investigated; it was shown that the damping is free at smaller values of the Womersley vibrational parameter, practically equal to zero, and at large values of which it asymptotically approaches unity.

Numerical modeling of vibration fatigue of viscoelastic pipelines conveying pulsating fluid flow

The effect of investigation results on viscoelastic properties of the material and bases on vibration fatigue of a pipeline conveying pulsating fluid flow is given in the paper. A mathematical model of viscoelastic pipeline vibrations based on the theory of beams was developed when a pulsating fluid flows through it. A computational algorithm has been developed to solve vibration problems of composite pipelines conveying pulsating fluid. Stability and amplitude-time characteristics of vibrations of composite pipelines conveying pulsating fluid were studied at wide range of parameters variation of deformable systems and fluid flow.

Analytical Modeling and Simulation of an Electromagnetic Energy Harvester for Pulsating Fluid Flow in Pipeline

This paper presents the analytical modeling and simulation of an electromagnetic energy harvester (having linear behaviour) that generates power from pulsating fluid flow for pipeline condition monitoring systems. The modeled energy harvester is comprised of a cylindrical permanent magnet and a wound coil attached to a flexible membrane which oscillates due to the pulsating fluid flow in the pipe over which the prototype is considered to be mounted. In the harvester electrical energy is produced due to the relative motion between the coil and magnet. Based on the harvester’s architecture a lumped parameter model (single degree of freedom system) is developed and is simulated at different physical operational conditions. The simulation is performed at pressure amplitude of 625 Pa. When subjected to the operational frequency sweep, at the harvester’s resonant frequency (500 Hz) and damping ratio of 0.01, the devised model predicted the maximum open circuit voltage of 2.55 V and load voltage of 1.27 V. While operating under resonance, the maximum load voltage of 2.45 V is estimated at load resistance of 100 Ω. However, at an optimum load of 4.3 Ω, the simulation shows a production of 188151.2 μW power at a frequency of 500 Hz.

Evaluation of the cavitation generator efficiency in the hydro impulsive loosening of a coal-bed

The paper presents the results of mining and experimental work, bench tests and theoretical studies of the energy characteristics of the stationary and pulsating fluid flow, which allow to estimate the efficiency of the cavitation generator in the hydro impulsive loosening of an outburst-prone coal-bed. The active stage of the hydro impulsive loosening and the effective range of the amplitude-frequency (AF) spectrum of the generator operation acoustic signal have been established by the AF spectrum of the sound accompaniment of the hydro impulse impact and the backup pressure of the liquid in the well. By calculation for this range the energy characteristics of the static and dynamic components of the pulsating fluid flow were determined. This made it possible to determine that the efficiency of the cavitation generator, all other conditions of the coal-bed hydro loosening being equal, is 4.8–1.2 times higher than the efficiency of the static impact.