International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

At the present days the great attention is given to a problem of research of hydrodynamics and heat exchange in the pulsating flows. Experimental studies for the flow in smooth channels show that the pulsation of fluids flow significantly affects to the heat transferring and can be accompanied by both reduction and increasing in the intensity of the heat exchanging. This problem has a big practical importance in the study of unstable processes in a various moving and power plants. The results showed that with unsteady fluid’s flow with a alternating pulsations relative to the average velocity in a discretely rough channel is furthering to the intensification of the heat transferring. It is shown that flow pulsations significantly affecting on the heat transferring coefficient, and its average values. This fact opens up the possibility of using such currents to increase the energy efficiency of various technical devices.

Basic methodology has been developed for a numerical modeling and heat exchange in a smooth channel and in a channel with a discrete roughness in the form of semispherical dimples. The methodology provides a possibility of computerized parametric calculations that adequately enough model the examined physical phenomena and allow to determine their characteristics being of practical interest. The efficiency of the examined discretely rough surface was estimated based on the coefficients of heat transfer and hydraulic resistance.

The subject of this paper is the analysis of stress distribution of the pipeline branch in hydropower. Pipe branches are widely used and very in complexity of the shape. Behaviour of the pipe branch subjected to the internal pressure was analyzed both numerically and experimentally. Analytical stress calculations are limited on the simpler forms of branches, so numerical calculations had to be used. Focus of numerical analysis was on determining critical locations and its values. Strain gauge method was used to measure greatest stress concentrations on the defined locations. Experimental results were very close to numerical calculations. Material used for manufacture of the pipeline branch is NIOVAL 47. This paper can be used as the base for the future researches concerning stress distribution in other branches among the pipeline both numerically and experimentally.