Litteris et Artibus

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    Efficiency criterion of CFD-modelling for studying the ultrasonic flowmeters
    (Lviv Polytechnic Publishing House, 2016) Roman, Vitalii; Matiko, Fedir; Lviv Polytechnic National University
    The paper presents a efficiency criterion of CFD-modelling for the research of ultrasonic flowmeters. He is a relative error of reproduction of mass flow rate in the i-th section 3D layout measuring pipeline. The authors investigated the influence of this criterion of effectiveness various options CFD-modelling.
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    Hydrodynamic flow measurement error of ultrasonic flowmeters
    (Видавництво Львівської політехніки, 2017-12-23) Roman, Vitalii; Matiko, Fedir; Kovalchuk, Ivanna; Lviv Polytechnic National University
    In this work the essence of hydrodynamic flow measurement error of ultrasonic flowmeter (USM). The methods of eliminating this error are analyzed. One of these methods is considered in detail – optimization of the location schemes of chordal acoustic paths (APs) of USM. The optimization is performed on the basis of the analytical-empirical power law of the distribution of the velocity of the undistorted flow. As a result of the work, the authors calculated the optimal location of the APs for chordal schemes of two- and three-path USMs. It was established that optimization of the location schemes of APs chordal USM allows to reduce the hydrodynamic flow measurement error to a value of 0.05 %(for USMwith two hordal APs) and 0.1 %(for USMwith three chordal APs). The developed approach is convenient when designing multipath USM and their research in laboratory conditions.
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    Investigation of ultrasonic flowmeter error in conditions of distortion of flow structure
    (Lviv Polytechnic Publishing House, 2015) Roman, Vitalii; Matiko, Fedir; Lviv Polytechnic National University
    Ultrasonic flowmeter error caused by distortion of flow structure has been investigated in this paper. Minimum number of acoustic chordal paths of multi-channel ultrasonic flowmeter was determined that ensures the error caused by distortion of flow structure less than the specified limits ±0.3 %. The authors used Salami velocity function as a model of distortion of flow structure. Acoustic path configurations of ultrasonic flowmeter were determined using classical numerical methods of integration of Gauss-Jacobi. The authors improved the flow rate equation of ultrasonic flowmeter by introduction of calibration coefficient that was determined using symmetric component of Salami function.