ISSN 2343–7707 ; ISSN-L 1453-7303

HIDRAULICA Magazine No. 4 / 2019

Hidraulica no.4/2019

Examining Centrifugal Pump on Cavitation
Authors: Nikolett FECSER, Balázs SÁRA, Rajmund KUTI

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 … (read more)

The Influence of the Fluid Nature on the Driving Power of a Rotating Volumetric Pump with Profiled Rotors
Authors: Mariana Mirela STOICAN (PRISECARU), Nicolae BĂRAN,
Almaslamani Ammar Fadhil SHNAWA, Mihaela CONSTANTIN

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(read more)

Design of a Bionic Arm Using Rapid Prototyping Technology
Authors: Adrian ȚÎMPEA, Cristian COSMA, Cosmin CODREAN, Aurelian MAGDA

This paper presents a 3D printable design for a myoelectric prosthetic arm which is electronically actuated and controlled by a user flexing muscles. The prototype has the potential to be used by an amputee or person born without a limb. In these days, a rapid prototyping (RP) technology as Fused Deposition Modeling (FDM) allows individuals to become small-scale manufacturers. Using RP technology to obtain physical parts for the bionic arm has a high impact due to … (read more)

Dynamic Analysis of a Centrifugal Pump using CFD and FEM Methods
Authors: Nicolae IACOB, Nicușor DRĂGAN

The article analyses the performances of a centrifugal pump using the Computational Fluid Dynamic (CFD) method, a computer numerical simulation method that was performed with specialized software in dynamic fluid flow analysis, ANSYS Workbench, using the FluidFlow (CFX) module. With this, the performances parameters of a centrifugal pump were determined: the inlet pressure and the outlet pressure of the pump, the flow of the pump, the speed of the fluid through the pump, the cavity of the pump. Using the finite element method (FEM) for solid bodies, the stresses and deformations occurring in the rotor blades were determined. For this part of the study, the Static Structural module from  … (read more)

Modelling and Sensitivity Study of a Firefighting System
Authors: Flóra HAJDU, Rajmund KUTI

For safe operation of firefighting systems it is essential to study the operation conditions, especially in case of mobile fire pumps, which are sometimes used by firefighters under extreme conditions. Changes in operation parameters can have a serious impact on the amount of water that can be extracted from the system, and thus on the effectiveness of firefighting itself. Therefore, the study of the topic is an important current issue. During this research a simulation model of a firefighting system was created. In this paper the developed model is presented first, which is followed by (read more)

Marine Impressed Current Cathodic Protection System
Authors: Mihail-Vlad VASILESCU, Mariana PANAITESCU, Fănel-Viorel PANAITESCU

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 (read more)

Experimental Research on the Processing of Convex Spherical Surfaces with Toroidal Mills versus Spherical Mills
Author: Andrei OȘAN

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 (read more)

Optimal Design of a CNG Storage Tank with a Combined Form Consisting of a Torus and a Sphere
Authors: Mihai ŢĂLU, Ștefan ŢĂLU

This paper presents the optimum sizing of a storage tank composed of a torus and a sphere, made of steel, intended for compressed natural gas (CNG) storage from the automotive industry. A design strategy was proposed to determine based on the finite element method, the optimum thicknesses of the torus and spherical coverings, with the correction of their thickness taking into account: the temperature variation, the corrosion action during the operation, the tolerances of execution of the sheet laminate, and the technological process used to manufacture the elements. Numerical simulations were carried out to determine … (read more)

River-Bed Processes Numerical Analysis in the Influence Area of a Crossing Structure
Authors: Alina-Ioana POPESCU-BUȘAN, Marie Alice GHIȚESCU, Albert Titus CONSTANTIN,
Şerban-Vlad NICOARĂ

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 … (read more)

The Influence of Corrosion and Temperature Variation on a CNG Storage Tank with a Combined Form Consisting of a Torus and a Sphere
Authors: Mihai ŢĂLU, Ștefan ŢĂLU

The objective of this paper is to study the influence of corrosion and temperature variation on a CNG storage tank with a combined form consisting of a torus and a sphere, made of steel, for compressed natural gas (CNG) storage from the automotive industry. Numerical simulations had been performed to assess the influence of the corrosion and temperature variation on the state of stress and of the linear deformation values. A polynomial interpolation was applied to provide a comparison between … (read more)

Aspects of the Operation of the Blade Pumps Used in Agricultural Irrigation Applications
Author: Fănel Dorel ȘCHEAUA

The population increase rate represents a factor of progress registered as a result of the people living standard improvement. This increase must be sustained worldwide through improved agricultural practices that allow to obtain optimum yields on cultivated lands that guarantee the well-being of human communities first and foremost in terms of providing food and related economic activities. The agricultural productions have had remarkable increases on the units of cultivated areas in the last years, which denotes … (read more)

The Construction of Systems for Air Dispersion in Wastewater
Authors: Titu – Cătălin CIOIENARU, Nicolae BĂRAN, Octavian DONȚU, Daniel BESNEA,

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 (read more)

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