http://elar.nung.edu.ua/handle/123456789/30 The scientific journal 2026-04-04T11:24:50Z http://elar.nung.edu.ua/handle/123456789/102 Title: Control of surface aktive agents content in agueous environment by measuring surface tension Authors: Kisil, I. S.; Bodnar, R. T.; Patlovskyy, I. R.; Malko, O. H.; Kuchirka, Yu. M. Abstract: Surface tention (ST) is a physical-chemical parameter that informs about the presence of surface-active agents (surfactants) in the aqueous environment. The article proposes to obtain experimentally ST (1ST) time dependence of the controlled aqueous environment and to judge by the equilibrium ST value (EST) about the surfactant concentration in such an environment, based on the previously received calibration dependence of EST on the concentration of respective surfactant in the aqueous environment. EST dependence of controlled aqueous environment is recommended to get though ST measurements by pulsing meniscus method based on the measurement of maximum pressure in the bubble (MPB) without its separation.The essence of pulsing meniscus method has been described. The advantage of this method over usual MPB method is that in the process of obtaining 1ST dependence and EST value one should use the same air meniscus surface at the end of metering capillary submerged in the sample of the investigated aqueous environment. It considerably speeds up the process of getting 1ST dependence and EST value of aqueous environment. The article contains a block diagram, appearance and work description of a device that implements pulsing meniscus method with the application of microcontrollers and hydraulic damper of depth of the metering capillary submersion in the controlled aqueous environment. Calculation of ST value on the basis of the measured maximum pressure drop Afmax m me meniscus pulsation process could be accomplished by one of the proposed dependences and methods (M. Cantor, R. Feustel, E. Schrodinger, J. Dugne, S. Sudgen, R. Bendure, I. Kisil). Recommended ranges of values for the parameter Apgr/Apm;a have been demonstrated, where relative methodological error of the calculation results of ST values will not exceed 0.1%, where Ap is the densities difference of the controlled aqueous environment and air, g is the acceleration of free fall and r is an outlet radius of the device metering capillary. 2014-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/100 Title: Modeling of ultrasonic guided waves propagation in a waveguide with cros-section of finite size Authors: Mandra, A. A.; Lyutak, I. Z.; Lyutak, Z. P. Abstract: The most topical task is further development of testing methods of oil and gas industry objects by ultrasonic guided waves. The aim of research is to develop mathematical model of ultrasonic guided waves propagation in oil and gas pipelines made from steel. The method of research is a computer modelling of ultrasonic guided waves propagation in waveguides with cross-sections of finite size. Calculations of guided waves propagation have been performed in two spectral ranges. With the increase of frequency an algorithm finds the same number of modes in a more narrow frequency spectra. Numerical results of found modes were estimated by effective mass criterion. The criterion shows that only a few modes from the found set correspond with applied boundary conditions of ultrasonic guided waves propagation. Results of calculations are applied to ultrasonic guided waves propagation along the V weld. Welded joints sizes meet requirements of normative documents about oil and gas main pipelines. In the paper it is specified that the parameters of ultrasonic guided waves propagation in a waveguide with its cross-cuts of finite sizes can be calculated utilizing existent algorithms realising search of eigenvalues, based on Timoshenko beam which is a finite element typelt has been found out that not all results of eigenvalues calculation by the algorithm with boundary conditions that describes propagation of guided waves with specified wavenumber correspond to propagation of the modes. The results of calculations have to be filtered out by the criterion of effective mass. It has been shown that the criterion of effective mass of a mode can be used to determine the type of guided wave. It has been found out that modes, propagating in a waveguide with its cross-cuts of finite sizes, can have marked torsional displacements without additional axial movements. 2014-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/99 Title: Optimization of the differential pressure flowmeters by means of "RASKHOD-RU" CAD Authors: Pistun, Ye.; Lesovoy, L.; Fedoryshyn, R. Abstract: New methodology of designing of the differential pressure flowmeters, which are optimal as to the accuracy of flowrate measurement is developed in order to provide minimum uncertainty of flowrate measurement results. This methodology is implemented in "Raskhod-RU" CAD system for computer aided design and calculation of differential pressure flowmeters. "Raskhod-RU" CAD meets the requirements of the new Standards (DSTU GOST 8.586.1,2,3,4,5-2009 and GOST 8.586.1,2,3,4,5-2005) and provides accomplishment of the following tasks: verification of conditions (constraints) for the application of the differential pressure method according to the requirements of the new Standards; calculation of primary device parameters, pipe straight lengths and flowmeter in general according to the requirements of the new Standards; calculation of uncertainty of fluid flowrate and volume measurement results; design of an optimal flowmeter as to the accuracy of flowrate measurement. 2014-01-01T00:00:00Z http://elar.nung.edu.ua/handle/123456789/98 Title: Modeling of fluid flow in pipeline with the leaks due to the surface Authors: Oliynyk, A. P.; Shtayer, L. O. Abstract: A mathematical model of viscous fluid flow in the pipeline with the presence of leaks due to their surface, which is based on a system of Navier-Stokes equations in two-dimensional rectangular region with a special type of boundary conditions has been designed. The geometric configuration of the leakage zone is taken into the account. It is believed that the fluid motion is under the influence of constant length of pressure difference. For the solving of this system, the numerical method of finite differences was developed by which the finite differences scheme is realized - the first step is implicit in longitudinal coordinate, and the second - on the transversal. The study on the stability of the spectral features method, stability conditions are established for the case of flow calculation with specified parameters and for the given type of the pipeline geometry. The calculations were made for a wide class of boundary conditions that established the patterns of distribution of velocities in different configurations and leakage areas in their absence, it was found that conspicuous effects of leaking occuring in the area around the pipe walls. The pattern of deviations from symmetry of the distribution of values of the longitudinal component was establishe, it depends on the distance of the leak, of the speedchange of the zone near the pipe wall, it also depends on the leakage intensity and the estimated parameters of the grid. It was set that the behavior of the flow in the zone near the wall after the longitudinal component derivative turned zero. The results can be used in designing the localization of small oil leaks from different areas of leakage configuration, the indicated technique can also be used in the study of utility and process piping in many different industries. It was found that the developed method adequately describes the phenomenon. Directions for further research are as follows: identification of dependencies different kinds of liquids, piping specifications, configuration leakage areas and exploration of the case for more complex dependencies pressure on the coordinates of the investigated area. 2014-01-01T00:00:00Z