Mobiliųjų mašinų hidraulinių pavarų energinio efektyvumo tyrimas

Research work relevance is concerned with global energy-saving trend, which is crucial for the transport sector as well. Dissertation work presents a study of efficient indicators of mobile machinery hydraulic drive elements for energy-saving. Different theoretical analyses and evaluations, experimental investigation and numerical simulation methods are applied for complex research, to suggest efficiency improving implements of using hydraulic drives and getting a better understanding of energy-saving by reducing fluid pulsation and minimization hydraulic resistance. In the introduction, the importance of the thesis, aim and tasks of researching work are presented. Scientific novelty, the theoretical and practical significance of results that were achieved, defendable statements and author published scientific papers are presented. Overview of scientific state-of-art according to dissertation theme presented in the first chapter. Different energy-saving methods and technologies in modern mobile machinery hydraulic drives were reviewed according to other scientific works, and the influence of these methods on energy-efficient problemating was discussed. In addition, scientific literatures in research area of fluid pulsation in hydraulic drives, the problem of hydraulic composite high-pressure hoses deformation investigation and the problem of fitting connections was described. The second chapter represents different research work methodologies, which were applied for the theoretical analysis and numerical simulation, models calculations and pre-experimental tests. In this chapter mathematical models of axial-pistons pump for investigation high pulsation inside hydraulic lines are presented. Pre-experimental tests of pressure losses on fitting connections and spectrum analyses of high-pressure hose composite material are investigated. A mathematical model of high-pressure hose and methodology of determination the parameters of rheological models of the viscous-elastic high-pressure hose material was presented. Modelling of fluid flow through different fitting connections and research of power losses on investigated objects were presented. Experimental test results of high-pressure hoses deformation and frequency response, fluid pressure drops and measuring of high fluid pulsation presented in the third chapter. Analysis of the system element energy efficiency were presented additionally in the third chapter. Nine scientific articles focusing on the subject of the dissertation was published: two – in a scientific journals, included in the Clarivate Analytics Web of Science databases with IF; one – in Clarivate Analytics Web of Science database Conference Proceedings; two – in a peer-reviewed scientific journals; four – in peer-reviewed international conference materials.Doctoral dissertatio