Here below we post a list of
Papers already accepted for publication in Issue 4/2019 of HIDRAULICA.
The list displays paper title, author(s) and affiliation, and also paper abstract.
Full-length paper will be available online only after publication.
Examining Centrifugal Pump on Cavitation
Assist. Prof. PhD. Stud. Eng. Nikolett FECSER1, Senior Seal System Project and Standardization Eng. Balázs SÁRA2, Associate. Prof. PhD.Rajmund KUTI1
1Széchenyi István University, Department of Mechatronics and Machine Design, Győr, Hungary
2FLOWSERVE HUNGARY SERVICE, Budapest, Hungary
Pumps influence all our lives directly or indirectly. Pumps are one of the most well-known and widespread type of a machine. Their task is to move fluid from one place to another, generally from a lower place to a higher one in a certain distance. For the safe operation of the pumps, it is essential to examine the operating parameters. The majority of specialists who are experts in pump technologies are familiar with cavitation. They are aware of its detrimental effects. Firstly, in our study we will briefly present the cavitation as a phenomenon. We will briefly present the place of measurement. Then we state the results of our measurements carried out type BKS 300. Finally we present regression calculation for BKS 300 type pump for H-NPSH curve. Our goal is to call attention to the proper way of operating centrifugal pumps, the cavitation generated during operation as a harmful phenomenon and its development examined in practice by us.
Marine Impressed Current Cathodic Protection System
PhD. Student Mihail-Vlad VASILESCU1, Prof.PhD.Eng. Mariana PANAITESCU1, Prof.PhD.Eng. Fănel-Viorel PANAITESCU1
1Maritime University of Constanta, Romania
The paper presents Marine Impressed Current Cathodic Protection system like a method of protection of the ship against corrosion. By installing and developing ICCP systems, we minimize the risk of failures or major renewals of hull structures, propeller and other still or iron parts of the vessel, which can be attacked by corrosion, during the ship’s expected life time and like this also ship owners can cut down repair costs.
This article major points are: how to design and choose the best Impressed Current Cathodic Protection system – ICCP for a ship, what are the main components and how it works an ICCP system, types of anodes, what parts of the ship the ICCP system can protect, installation of the system components and maintenance.
The Construction of Systems for Air Dispersion in Wastewater
PhD Student Titu – Cătălin CIOIENARU1, Prof. Dr. Eng. Nicolae BĂRAN1, Prof. Dr. Eng. Octavian DONȚU1, Conf. Dr. Eng. Daniel BESNEA1, Dr. Eng. Corina MOGA2, PhD Student Mihaela PETROȘEL1, Sl. Dr. Eng. Mihaela CONSTANTIN1
1University Politehnica of Bucharest, Romania
2DFR Systems SRL, Bucharest, Romania
For an efficient aeration of wastewater, two options are proposed:
1) In the case of stagnant waters the use of fine bubble generators; these fine bubble generators ensure accurate and uniform air dispersion;
2) In the case of the water flowing through the pipes, the aeration of the water will take place right inside the pipes, thus eliminating those huge aeration tanks used for water treatment.
The pipes carrying the wastewater can be placed horizontally or vertically; only horizontal pipes will be analysed in the paper.
The Influence of the Fluid Nature on the Driving Power of a Rotating Volumetric Pump with Profiled Rotors
PhD Student Mariana Mirela STOICAN (PRISECARU)1, Prof. Dr. Eng.Nicolae BĂRAN1, PhD Student Almaslamani Ammar Fadhil SHNAWA1, Sl. Dr. Eng. Mihaela CONSTANTIN1
1University Politehnica of Bucharest, Romania
The term rotating volumetric machine with profiled rotors refers to the following:
– The constructive solution of the rotating machine can be used as a force machine (steam engine, pneumatic engine);
– Or it can be used as a working machine (pump, fan, and compressor).
The constructive solution and the operation mode of the volumetric pump with profiled rotors are presented, and based on the functional parameters (speed and flow rate) the correlation between the driving power and the conveyed fluid nature is established.
The data obtained theoretically are verified by means of an experimental installation built for this purpose.
River-Bed Processes Numerical Analysis in the Influence Area of a Crossing Structure
Assist. dr.eng. Alina-Ioana POPESCU-BUȘAN1, Assist. dr.eng.Marie Alice GHIȚESCU1, Assoc.prof.dr.eng. Albert Titus CONSTANTIN1, Lect.dr.eng. Şerban-Vlad NICOARĂ1
1University Politehica of Timisoara, Romania
There is described a 1D numerical study of scouring and sedimentation processes on a specific altered river sector. The model developed and analysed by the help of HEC-RAS software package is concerned by the immediate upstream and downstream vicinity of an existing road bridge. The general quasi-unsteady (transitory) flowing regime assimilates a given hydrologic development unfolding over a generous time period, from August 1st, 1985 to July 31st, 1988.
The present paper considers a casual approach by which the specific crossing structure is replaced by two characteristic cross-sections along the concrete bridge faces. The scourings expansion and depth or the silting spread and height can so be revealed especially along the bothering bridge span but also along the influenced river sector as modelled.
Experimental Research on the Processing of Convex Spherical Surfaces with Toroidal Mills versus Spherical Mills
PhD. Student Eng. Andrei OȘAN1
1Technical University of Cluj-Napoca – North University Center of Baia Mare, Romania
The surface roughness plays a very important role on the wear layer, on the precision as well as on the lubrication environment. In terms of determining the quality of the surface, this is a complex process and highly influenced by the process factors. The present paper aims to determine the roughness of the convex spherical surface by using two types of mills with different geometries. The toroidal and spherical mills are subject to comparison. The processing with the two types of milling machines presents the processing with three variable regimes the rest keeping cash. In addition to determining the best quality obtained and the shortest execution time.