buletinul institutului politehnic din iaşi bulletin of the polytechnic ...

More documents

Recommendations

Info

method). The functional diagrams allow obtaining the graphical representation of the level of the liquid from the reservoir during the time of the emptying process but also the graphical representation of the flow rate of the liquid through the orifice. Using the measured values of flow rate, the velocity and the Reynolds number can be calculated. A comparative analysis of the numerical results for the emptying time for constant head and for variable head reservoirs, obtained with the analytical and the functional diagram methods will be presented. Key words: constant cross-sectional area reservoir, emptying time, emptying orifice, functional diagram, MATLAB. FUNCTIONAL DIAGRAMS FOR MODELING THE RESERVOIR EMPTYING PROCESS THROUGH AN EMPTYING PIPE by DĂNUŢ ZAHARIEA Abstract. In this paper the emptying process of constant head and variable head reservoirs with constant cross-sectional area through an emptying pipe will be investigated. The pressure at the water surface and also the velocity of this surface, as well as the head loss due to friction along the emptying pipe will be considered. Two methods will be presented: the analytical method based on the fundamental equations governing the reservoir emptying process and the functional diagrams method based on MATLAB/Simscape computational approach suited to analyze the real physical systems. A comparative analysis of the numerical results for the emptying time for constant head and for variable head reservoirs, obtained with the analytical and the functional diagram methods will be presented. Key words: constant cross-sectional area reservoir, emptying time, emptying pipe, functional diagram, MATLAB. A PLEADING FOR THE MODERNIZATION OF MACHINE TOOLS IN NATIONAL INDUSTRY by DAN POPESCU
Abstract. Numerical controls have a great role in increasing the efficiency of the electric drive of the machine tool, thus in the energy saving. Measurements were done for two of those (one equipped with numerical control and a converter for the asynchronous motor of the main drive, and another with no numerical control and with a converter for the d.c. motors of the main drive). Measurements were done using a kit which was specialized in acquiring and handling energetic data. This project presents the diagrams resulted from the measurements in a comparative study. The monitored parameters were the following: actual values of voltage and currents during the three phases, the content of harmonics, or the frequency spectrum for all three phases, the frequency of the feeding voltage, active and reactive power, energy, and the power factor. Key words: numerical controls, active and reactive power, energy, converter.
Page 1 and 2: B U L E T I N U L I N S T I T U T U
Page 3 and 4: BRUNO RĂDULESCU and MARA-CRISTINA
Page 5 and 6: RESEARCH ON EXPERIMENTAL HEAT EFFEC
Page 7 and 8: EXPERIMENTAL RESEARCH REGARDING THE
Page 9 and 10: Ansoft. A dc applied magnetic field
Page 11 and 12: Abstract. Quality management is bro
Page 13 and 14: FINITE ELEMENT MODELING OF A KNEE A
Page 15 and 16: Abstract. This paper presents the d
Page 17: CONSIDERATIONS ABOUT CONTROL CHARTS

buletinul institutului politehnic din iaşi bulletin of the polytechnic ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?