Volumul 25


26-11 TEHNOLOGIE DE EPURARE BIOLOGICĂ CU TUBURI POROASE ŞI TUBURI CU MEMBRANĂ ELASTICĂ PERFORATĂ ȘI DIMENSIONAREA INSTALAȚIILOR DE AERARE

TECHNOLOGY FOR WASTE WATER TREATMENT WITH
POROUS TUBE AERATORS AND ELASTIC PERFORATED
MEMBRANE TUBES OF THE BIOLOGICAL
WASTE WATER TREATMENT
The paper is to review and assess existing design procedures and provide
in-depth design information on critical features of the aeration process using Tube
aerators porous and elastic membrane tubes and key parameters affecting its
operation and performance that is typically available to the engineering community.
Since past decade, the old works started to be replaced with new technologies such
as those using tube aerators porous and elastic membrane tubes, especially for
industrial and municipal waste water treatment plants. This paper discusses the
theory, performance, design procedures, calculation and dimensioning of the
aeration using Tube aerators porous and elastic membrane tubes.
Keywords: aeration, porous tubes, tubes with elastic membrane, aeration
plants, wastewater, and wastewater treatment schemes
Cuvinte cheie: aerare, tuburi poroase, tuburi cu membrana elastică, instalații
de aerare, ape uzate, scheme de epurare
Descarcare text


25-86 SOLUŢII PENTRU ÎMBUNĂTĂŢIREA MĂRIRII CAPACITĂŢII PORTANTE A STRUCTURILOR DE REZISTENŢĂ ÎN CAZ DE INCENDII

ACCOMPLISHMENTS FOR THE FIRE RESISTANCE LOAD
BEARING CAPACITY IMPROVING OF THE STRUCTURES
The authors of the contribution presents several possible solutions
destined to improving the load bearing capacity of the steel structural elements.
In this sense, are described some existent solutions, respectively two other
originals, ones. Every solution is analyzed from their usefulness’ point of view,
respectively their limits. The original solutions/proposals seem to fulfil several
major fire safety criteria, mainly to increase the safe period of the structural
elements. The authors intend applying one of them in a forthcoming PhD
thesis experimental part.
Keywords: Steel structures, fire, load capacity, protection against fire
Cuvinte cheie: structuri metalice, incendii, capacitatea portantă,
protecţie la foc
Descarcare text


25-85 VERIFICAREA STRUCTURII DE REZISTENŢĂ LA VAGOANELE DE MARFĂ DESCOPERITE CU PEREŢI ÎNALŢI UTILIZATE ÎN TRANSPORTURILE UZINALE CU METODA ELEMENTELOR FINITE

CHECKING THE STRUCTURE OF RESISTANCE FREIGHT
WAGONS DISCOVER HIGH WALL IN TRANSPORT
FACTORIES FINITE ELEMENTS
This article aims to examine the structure simulating resistance to
compression of the buffers a freight wagon found with high walls used in
factories and railways removal solution validation platform Handbrake finite
element method.
Keywords: transport, freight wagon power roads, finite elements
Cuvinte cheie: vagon de marfă, transporturi uzinale, elemente finite
Descarcare text


25-84 ANALIZA EXPERIMENTALĂ A TENSIUNILOR ŞI DEFORMAŢIILOR LA VAGOANELE DE MARFĂ DESCOPERITE CU PEREŢI ÎNALŢI UTILIZATE ÎN TRANSPORTURILE UZINALE PRIN METODA TENSOMETRIEI ELECTRICE REZISTIVE

EXPERIMENTAL ANALYSIS OF STRESSES AND
STRAINS FREIGHT WAGONS DISCOVER HIGH WALL IN
TRANSPORT FACTORIES TENSOMETRIEI USING
ELECTRICAL RESISTIVE
This article aims to examine the resistance structure by static testing
with combined efforts from a freight car found with high walls to use railway
Factory method resistive electric tensometriei.
Keywords: transport, freight wagon power roads, tensions, deformations
Cuvinte cheie: vagon de marfă, transporturi uzinale, tensiuni, deformaţii
Descarcare text


25-83 ANALIZA NUMERICĂ A STĂRILOR DE TENSIUNI ȘI DEFORMAȚII DIN AXA TRIUNGHIULARĂ A TIMONERIEI DE FRÂNĂ DE LA VAGOANELE DE MARFĂ

TRIANGULAR AXIS BRAKE WHEELHOUSE FREIGHT
WAGONS NUMERICAL STRESS AND STRAIN ANALYSIS
The 120 kN triangular axes of the whellhouse is used for the bogie
Y25Rsa, Y25Ls(s)d, and to the whellhouse to brake the wheel two-axle
wagons, load of 22.5 tons/axle. These triangular axes are used for the
transmission and distribution of braking force to the wheels of each wheelset.
Keywords: triangular, wheelhouse axis brake, freight wagons
Cuvinte cheie: axa triunghiulară, timonerie frână, vagoane de marfă
Descarcare text


25-82 UZURA BILELOR DE RULMENT ÎNCERCATE LA OBOSEALĂ

WEAR AND TEAR OF FATIGUE-TESTED
BEARING BALLS
The bearing balls with the 12.7 mm diameter equipping radial bearings
were tested for the fatigue endurance stress. The test was performed on a
specialised machine, which creates a constant force during testing, at a number
of revolutions that is also constant. By weighing and dimensional
measurements we find a mass loss after the fatigue test, and implicitly the
diameter became smaller due to wear and tear.
Keywords: bearing ball, fatigue testing, ball wear and tear
Cuvinte cheie: bila de rulment, de oboseală, uzura bilei
Descarcare text


25-81 ANALIZA DIMENSIONALĂ ȘI CALITATIVĂ A SUPRAFEȚELOR BILELOR DE RULMENT ÎNCERCATE LA OBOSEALĂ

DIMENSIONAL AND QUALITATIVE ANALYSIS OF THE
SURFACE OF FATIGUE-TESTED BEARING BALLS
During the fatigue testing of bearing balls, subjected to compression at
constant force and number of revolutions, we find, from the technological point
of view, certain micron-sized alterations in relation with the dimensions and
quality of the tested balls’ surface. The main parameters refer to the ball
diameter [mm] and the number of revolutions affected by the machine during
testing [number of revolutions]. The contact during testing is sphere to plane.
Keywords: bearing ball, fatigue testing, roughness
Cuvinte cheie : bilă rulment, încercare de oboseală, rugozitate
Descarcare text


25-80 ANALIZA DURATEI DE VIAȚĂ A BILELOR DE RULMENT DE DIMENSIUNI MICI

ANALYSIS OF ENDURANCE LIFETIME FOR
SMALL BEARING BALLS
In order to determine the lifetime of bearing balls we need to proceed
to their fatigue test. The machine for fatigue testing has a special construction,
with several spaces for simultaneous tests. The contact between the ball to test
and the plate is plane. During the test, the machine’s number of revolutions and
the loading force are constant. An important parameter during testing is
represented by the environment conditions (with or without lubrication).
Keywords: bearing ball, fatigue test, endurance, lifetime
Cuvinte cheie: bila rulment; încercare la oboseală; durata de viață
Descarcare text


25-79 STUDII ASUPRA SOLIDIFICĂRII INTERSECȚIILOR ÎN FORMĂ DE T, A PEREȚILOR PIESELOR TURNATE

SOLIDIFICATION STUDIES T JUNCTIONS, WALLS CASTINGS
This paper aims to make a numerical and experimental analysis of the
succession of solidification zones of T-shaped intersection walls of cast
aluminium alloys. The idea of this study started with the observation that these
areas solidification thru dedicated method of cooling modules analysis does not
fully correspond to numerical analysis using a simulation solidification program.
By using the simulation software NovaCast it was studied the succession of
solidification process of T – shaped intersection of the walls of aluminium alloy
castings En AC-Al Si7Mg0,3 in several versions of ratio between the two
intersecting walls. Subsequently were made casts of this form examining their
solidification by determining the compactness of intersection and surrounding
areas. In interpreting the results obtained it can be concluded that the T-shaped
intersection of two walls, in most cases, doesn’t act as a heat node, as it would
be presumed at first glance.
Keywords: aluminum alloys, solidification, cast
Cuvinte cheie: aliaje, aluminiu, solidificare, turnate
Descarcare text


25-78 DETERMINAREA COMPORTAMENTULUI LA OBOSEALĂ A SÂRMELOR ZINCATE ȘI NEZINCATE UTILIZÂND PROGRAMUL DE SIMULARE ANSYS

DETERMINATION OF GALVANIZED WIRE FATIGUE
BEHAVIOR USING ANSYS SIMULATION SOFTWARE
Although the total number of parts that break during service is not
great, however over 50 % of the breaks are caused by fatigue cracking or
corrosion fatigue, and so is of a great importance the knowledge and mastery
of this phenomenon.
This study discusses the fatigue behaviour of the wires, making a
comparison of results obtained on galvanized wire specimens and on
ungalvanized wire specimens, using Ansys analysis program.
Keywords: fatigue, meshing, CAD model, number of cycles
Cuvinte cheie: oboseală, discretizare, model CAD, număr de cicluri
Descarcare text


25-77 STUDIU ISTORICO-CRITIC AL ANALIZEI DIMENSIONALE

HISTORICO-CRITICAL REVIEW OF DIMENSIONAL ANALYSIS
On the base of numerous literatures a critical review of main facts and
events that played a significant role in the history of dimensional analysis will be
presented. Dimensional analysis appeared in the antiques with the necessity to
qualitatively describe and understand the physical world and was fructuously
developed in the works of Galileo Galilei, Pierre-Marie-François Daviet de
Foncenex, Jean Baptiste Joseph Fourier and John William Strutt. Application of
dimensional analysis on a large scale began after 1914, when Edgar
Buckingham demonstrated his Π− theorem and Percy W. Bridgman published
his „Dimensional analysis” in 1922.
Keywords: history, geometrical dimensions, physical dimensions,
principle of dimensional homogeneity, Π – theorem, dimensional analysis
Cuvinte cheie: istorie, dimensiuni geometrice, dimensiuni fizice, principiul
de omogenitate dimensională, teorema Π , analiză dimensională
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25-76 CONTRIBUŢII LA TEORIA ALGEBRICĂ A ANALIZEI DIMENSIONALE

CONTRIBUTIONS TO THE
ALGEBRAIC THEORY OF DIMENSIONAL ANALYSIS
Dimensional analysis is based on the tacitly accepted idea, that physical
quantities, units and their dimensions represents algebraically factors, with
which you can perform ordinary operations like with the numbers. To
demonstrate the viability of this idea in the present paper were formulated and
proved four theorems of algebraic theory of dimensional analysis, taking as
starting point the relation between the definition of the physical quantities and
the invariance principle of the physical laws. It also shows, whether two
quantities are mechanical in nature, the product or multiplier of them is also of
mechanical nature. This correlations can be extended to others physical
quantities such as heat, electricity, electromagnetic, chemical etc.
Keywords: physical quantity, unit, numerical value, dimension,
dimensional analysis
Cuvinte cheie: mărime fizică, unitate, valoare numerică, dimensiune,
analiză dimensională
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25-75 CONSIDERAȚII PRIVIND ÎNCERCAREA LA TRACȚIUNE A MATERIALULUI UZUAL FOLOSIT PENTRU PARAPETELE DE PROTECȚIE LA DRUMURI

CONSIDERATIONS ON TENSILE TEST OF USUAL
MATERIAL USED ON ROAD RESTRAINT SYSTEMS
The paper presents a comparison between the results of tensile test
experiments for the material used for road restraint systems, S235JR, black
and galvanized. Deformable road restraint systems protect the vehicles from
danger, which are forwarded on the carriageway minimizing serious injury.
After the execution of the restraint systems components, these are
promoted on the technological flow for hot dip galvanizing, being protected
against corrosion.
Keywords: tensile test, S235JR galvanized, road restraint systems
Cuvinte cheie: încercare la tracțiune, S235JR zincat, sisteme de
reținere rutiere
Descarcare text


25-74 CONSIDERAȚII PRIVIND LĂȚIMEA DE LUCRU A PARAPETELOR LA IMPACTUL CU O SFERĂ

CONSIDERATIONS REGARDING THE WORKING
WIDTH OF ROAD RESTRAINT SYSTEMS AT
THE IMPACT WITH A SPHERE
This paper presents the simulation of the behaviour of two types of
road restraint systems on impact with a sphere in different points from the pillar
axis. The working widths of the restraint systems during collisions are
presented. The working width is very important because it characterizes the
parapets during impact. The simulations were performed with the help of finite
element software using Altair Hyper Works modules.
Keywords: displacement of parapets, road restraint systems
Cuvinte cheie: deplasarea parapetelor, sisteme de reținere rutiere
Descarcare text


25-73 EVALUAREA TEORETICĂ A PERFORMANȚELOR UNEI BARIERE DE SIGURANȚĂ RUTIERĂ

THEORETICAL PERFORMANCE EVALUATION
OF A TRAFFIC SAFETY BARRIER
By definition, the railing is a wall or a railing of little height which serves
to delimit the edge of a road, a bridge, aimed at stopping vehicles and
restoration mainly on the carriageway, pedestrians and conveyance of other
road users. Protective guardrail road safety ensures good road contact because
a vehicle deforms elastically, annihilating shock.
Keywords: enclosures, endurance, steel, deformation, protection
Cuvinte cheie: carcase, rezistență, oţel, deformare, protecţie
Descarcare text


25-72 CONSIDERAȚII ASUPRA AMORTIZĂRII IMPACTULUI UNUI VEHICUL CU UN OBSTACOL RIGID Partea a II-a

REFLECTIONS ON A VEHICLE WITH AN IMPACT
DEPRECIATION RIGID OBSTACLE – Part II
Make a selection of work items and the factors that lead to unexpected
event called „traffic accident”. Are the concept of „safety” and the possibility of
its optimization. The paper is presented a solution to reduce the negative
effects that occur in the event of a frontal impact of vehicle with a fixed obstacle
through equipping its bumper with shock absorbers magneto rheological.
Keywords: bumpers, crash, car, traffic, obstruction, safety, obstacle
Cuvinte cheie: amortizor, accident, automobil, obstacol, siguranța,
circulație
Descarcare text


25-71 CONSIDERAȚII ASUPRA AMORTIZĂRII IMPACTULUI UNUI VEHICUL CU UN OBSTACOL RIGID Partea I-a

REFLECTIONS ON A VEHICLE WITH AN IMPACT
DEPRECIATION RIGID OBSTACLE – Part I
Make a selection of work items and the factors that lead to unexpected
event called „traffic accident”. Are the concept of „safety” and the possibility of
its optimization? The paper is presented a solution to reduce the negative
effects that occur in the event of a frontal impact of vehicle with a fixed obstacle
through equipping its bumper with shock absorbers magneto rheological.
Keywords: bumpers, crash, car, traffic, obstruction, safety, obstacle
Cuvinte cheie: amortizor, accident, automobil, obstacol, siguranța,
circulație
Descarcare text


25-70 DETERMINAREA TENSIUNILOR ŞI DEFORMAŢIILOR LA UN ARC ELICOIDAL CILINDRIC DE TORSIUNE

DETERMINATION OF STRESS AND STRAIN
IN A HELICAL SPRING TORSION
The paper presents the analysis of state of stresses and strains in
helical spring torsion. Stresses and strain were analysed in dependence of the
spring dimensional factor and the cross-sectional diameter
Keywords: spiral spring, tensions, deformations
Cuvinte cheie: arc elicoidal de torsiune, tensiuni, deformaţii
Descarcare text


25-69 STUDIUL EFECTULUI FORŢEI TĂIETOARE ASUPRA DEFORMAŢIILOR GRINZILOR DREPTE SOLICITATE LA ÎNCOVOIERE

THE STUDY OF THE ACTION OF THE CROSS FORCE
ON THE STRAIGHT BEAM BUCKLING IN CASE
OF BENDING STRESS
The following paper presents a study done by the author on the
straight beam buckling subjected to bending stress, by considering or
neglecting the effect of the cross force. The study was done on different forms
of the cross sections, respectively for different values of the ratio (relation)
between the height of the beam section and its length.
Keywords: bending moment, shear force, deformations
Cuvinte cheie: moment încovoietor, forţă tăietoare, deformaţii
Descarcare text


25-68 PROPAGAREA FISURII LA OBOSEALĂ AXIAL- EXCENTRICĂ. MODELE DE STUDIU

THE CRACK PROPAGATION AT ECCENTRICALLY
TENSILE FATIGUE TEST. STUDY MODELS
The study consists in crack propagation analysis in a plate specimen
CT model with side notch, made by a R520 steel. The specimen is loaded to a
eccentrically tensile test. The loading asymmetry factors are: R = 0.1 and R =
0.3, and the loading temperature is the room temperature, T = 293K.
The defect seeding rate in the specimen material marked as da/dN
was analysed by the empiric mathematical models: 1° – a second degree
polynomial method of approximation; 2º – according to Paris formula and, 3° –
respectively to Walker model. By using the three methods, there was
determined the crack propagation rate variation da/dN versus the crack length
variation a1, respectively versus the stress intensity factor ΔK.
Keywords: cyclic, request coefficient of asymmetry, cracking, cracking
speed, intensity factor in blood (FIT)
Cuvinte cheie: solicitare ciclică, coeficient de asimetrie, fisură, viteză
de fisurare, factor de intensitate a tensiunii (FIT)
Descarcare text


25-67 CÂTEVA ASPECTE ALE ESTIMĂRII TENACITĂŢII LA RUPERE PENTRU OŢELUL 12H1MF

SOME ASPECTS OF ESTIMATING THE FRACTURE
TOUGHNESS FOR 12H1MF STEEL
Between main characteristics, praising the fracture toughness of
materials, there are different relations. The present paper is praising some
difficulties which concerning the fracture toughness, on the basis of a method
which allow to estimate another characteristic, much easy to determine.
Keywords: steam pipe, toughness, steel 12H1MF
Cuvinte cheie: conductă de abur, tenacitate la rupere, oţel 12H1MF
Descarcare text


25-66 STUDIUL COMPORTĂRII STRUCTURILOR IZOLATE CU SISTEME PENDULARE

STUDY OF THE BEHAVIOUR OF STRUCTURES
INSULATED WITH FRICTION PENDULUM SYSTEMS – II
The earthquakes have been, and are a great danger against humanity.
The study presented in this paper aims to determine the response of an
insulated structure due to earthquakes vibration loads, which are randomly,
non-periodic and contain various frequencies. The study, made on a two-story
structure involved finite element analysis, to determine the displacements,
velocities and accelerations in various locations on the structure. The actual
results were obtained using statistical methods, in order to determine the
dynamic behaviour of a vibrating structure.
Keywords: base isolation, friction, pendulum, structure
Cuvinte cheie: izolator seismic, frecare, pendul, structură
Descarcare text


25-65 STUDIUL COMPORTĂRII STRUCTURILOR IZOLATE CU SISTEME PENDULARE CU FRECARE Partea I-a

STUDY OF THE BEHAVIOUR OF STRUCTURES INSULATED
WITH FRICTION PENDULUM SYSTEMS – I
The earthquakes have been, and are a great danger against humanity.
The study presented in this paper aims to determine the response of an
insulated structure due to earthquakes vibration loads, which are randomly,
non-periodic and contain various frequencies. The study, made on a two-story
structure involved finite element analysis, to determine the displacements,
velocities and accelerations in various locations on the structure. The actual
results were obtained using statistical methods, in order to determine the
dynamic behavior of a vibrating structure.
Keywords: base isolation, friction, pendulum, structure
Cuvinte cheie: izolator seismic, frecare, pendul, structură
Descarcare text


25-64 STUDIUL COMPORTĂRII DINAMICE A STÂLPILOR CU DIFERITE NIVELE DE ÎNCĂRCARE

A STUDY REGARDING THE DYNAMIC BEHAVIOR OF
COLUMNS SUBJECTED TO DIFFERENT TIP MASSES
The present study aims to highlight the effect of a tip mass upon the
behavior of columns. We have first analytically determined, for a specific
column, the critical buckling force to find the range in which it works in the
elastic domain. Afterwards, by means of numerical simulations, we performed
analysis regarding the influence of loads due to different additional masses and
have identified the effect upon the natural frequencies and modal shapes,
concluding that the higher the mode number, the higher the influence.
Keywords: column, buckling, natural frequency, simulation
Cuvinte cheie: stâlp, flambaj, frecvenţe proprii, simulare
Descarcare text


25-63 EFECTUL DEFECTELOR STRUCTURALE ASUPRA COMPORTAMENTULUI DINAMIC AL GRINZILOR COMPOZITE STRATIFICATE

EFFECT OF STRUCTURAL DAMAGES ON THE DYNAMIC
BEHAVIOUR OF LAMINATED BEAMS
This paper presents results obtained by modal analysis on composite
beam-like structures in healthy and damaged state. The aim is to obtain
damage “signatures” for all possible damage scenarios and to use these data
to assess transversal cracks based on vibration techniques, by involving natural
frequency shifts. The analysis was performed in SolidWorks software for a fivelayer
composite, 30 vibration modes being obtained by numerical simulations.
An example how to interpret the results is shown in the last section of the
paper.
Keywords: damage, finite elements, frequency, simulation, structure
Cuvinte cheie: defect, elemente finite, frecvenţă, simulare, structură
Descarcare text


25-62 STUDIUL EFECTULUI TEMPERATURII ÎN APARIŢIA TENSIUNILOR REMANENTE DIN CAZUL DISCURILOR DE GROSIME MICĂ. Partea a II-a: RELAŢII DE CALCUL PENTRU STABILIREA TENSIUNILOR REMANENTE

THE STUDY OF TEMPERATURE EFFECT IN THE RESIDUAL
STRESSES OCCURRENCE FOR THE CASE
OF LOW THICKNESS DISKS
PART II – THE CALCULUS RELATIONS FOR THE RESIDUAL
STRESSES DETERMINATION
In order to determine the stress and deformation state of some
structures one must know the residual stresses due to the temperature. One
considers the situations when the stresses reach the limits imposed by von
Mises criterion; plastic deformations will appear; these have as effect a
redistribution of residual stresses. In order to determine the residual stresses,
theoretical studies and experimental research, based on the section method,
have been done. One has studied the hot laminated structures. Following the
uniform cooling, residual thermal-elastic-plastic stresses appear in the material.
The performed determinations based on the section method lead to high
precision determination of the residual stresses field. The established
theoretical equations were also verified.
Keywords: residual stresses, plastic deformation, criteria, tension of
the membrane, plate
Cuvinte cheie: tensiuni remanente, deformații plastice, criterii, tensiuni
de membrană, placă
Descarcare text


25-61 STUDIUL EFECTULUI TEMPERATURII ÎN APARIŢIA TENSIUNILOR REMANENTE DIN CAZUL DISCURILOR DE GROSIME MICĂ. Partea I-a – STUDIUL PROPAGĂRII TEMPERATURII

THE STUDY OF TEMPERATURE EFFECT IN
THE RESIDUAL STRESSES OCCURRENCE FOR
THE CASE OF LOW THICKNESS DISKS
PART I – THE STUDY OF THE TEMPERATURE
PROPAGATION
In order to determine the state of stress and deformation due to the
temperature, one has to study, as exactly as possible, the temperature’s
propagation mode. There are many practical situations when in some bodies’
material exist self-balanced stresses, even in the absence of any load.
These are residual stresses. Their magnitude and their distribution
depend on the material, on the technological working process, on the machine
parts’ size. The residual stresses appear mainly because of the local
deformations in the elastic-plastic field, because of some structural
transformation or because of some thermo-elastic-plastic deformations.
The paper presents some aspects regarding the residual stresses due
to the heat treatment and to the shallow working.
Key words: residual stresses, deflections, temperatures, plastic plate
Cuvinte cheie: tensiuni remanente, deformaţii plastice, temperatură,
placă
Descarcare text


25-60 VARIAŢIA COEFICIENTULUI DE DEBIT LA ORIFICII MICI CU VÂSCOZITATEA ŞI TENSIUNEA SUPERFICIALĂ

THE VARIATION OF SMALL ORIFICES DISCHARGE
WITH VISCOSITY AND SUPERFICIAL TENSION
This paper presents a synthesis of theoretical and experimental
results concerning the discharge coefficient of hydraulic orifices and its
dependence on Reynolds number for the case of fluids with known physical
properties. The experimental researches performed in laboratory emphasize
the influence of superficial tension and viscosity on the discharge through a
small orifice of 3 mm diameter. For the investigated range of superficial
tensions and viscosities (σ = (23 ÷ 80) ·10-3 N/m and η = (1.1 ÷ 910)·10-3 Pa·s),
there was found a linear dependence of discharge on lg Re and lg100We.
Keywords: orifice, discharge coefficient, superficial tension, viscosity
Cuvinte cheie: orificii, coeficient de debit, tensiune superficială,
vâscozitate
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25-59 METODA ELEMENTELOR DE FRONTIERĂ CU ELEMENTE LINIARE, PENTRU O REŢEA AXIALĂ ÎN ”S” Partea a II-a

BORDER ELEMENT METHODS WITH LINEAR ELEMENTS,
FOR A NET AXIAL „S” – Part II
This paper, for a reversible cascade ”S” axial profiles., presents
boundary element method (BEM), with linear elements, for the numerical
simulation of ideal incompressible fluid. BEM apply for Laplace’s equation
depending on flow and hydrodynamic field, speed and pressure are obtained,
inside of domain analysis for a axial “S” axial cascade.
Keywords: axial “S” axial cascade, linear elements, BEM, Laplace
equation, hydrodynamic field
Cuvinte cheie: cascada axială axial „S”, elemente liniare, BEM,
ecuaţia lui Laplace, domeniul hidrodinamic
Descarcare text


25-58 CONSIDERAŢII PRIVIND OPTIMIZAREA FORMEI DISCULUI LA O VANĂ FLUTURE PENTRU REDUCEREA COEFICIENTULUI DE REZISTENŢĂ HIDRAULICĂ

CONSIDERATIONS REGARDING THE BUTTERFLY VALVE
DISK SHAPE OPTIMISATION FOR DECREASING OF THE
RESISTANCE COEFFICIENT
The paper presents the optimization of the butterfly valve disc shape
to obtain a hydraulic resistance coefficient of 0.07 by numerical methods and by
experimental measurements. The optimized butterfly valve disc model on which
measurements were done and the results of the model tests are presented.
The results of the model tests consist of determining the hydraulic resistance
coefficient and consequently the flow coefficient and of the forces and moment
coefficients, the coefficient of cavitation and vibration level.
Keywords: van butterfly, disc biplane, coefficient of resistance
Hydraulic, numerical methods
Cuvinte cheie: vană fluture, disc biplan, coeficient de rezistenţă
hidraulică, metode numerice
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25-57 PROIECTAREA INSTALAŢIEI ELECTRICE CU SISTEM FOTOVOLTAIC OPTIM CUPLAT LA REŢEA, CU AJUTORUL UNUI SOFTWARE DEDICAT

ELECTRICAL DESIGN OF OPTIMUM PHOTOVOLTAIC
SYSTEM COUPLED TO THE NETWORK WITH
A DEDICATED SOFTWARE
In article, it will design and simulate using Sunny Design dedicated
software, version 2.30.0, a photovoltaic system connected directly to the
network, for a villa located in Reşiţa, Caraş-Severin region, Romania.
In the first variant we find that 38.3 % of the electricity produced by the
solar panels is required of the users of the villa, the remaining 61.7 % can be
offered for sale. The second variant, we find that 26.4 % of the electricity
produced by the solar panels is required of the users of the considered case,
the remaining 73.6 % can be given for sale. It appears that option 2 is the
optimum solution.
Keywords: optimization, design, networking, SUNNY coupling DESIGN
version 2.30.0
Cuvinte cheie: optimizare, proiectare, cuplare la reţea, SUNNY DESIGN
versiunea 2.30.0
Descarcare text


25-56 STUDIU PRIVIND REPARAŢIA PRIN SUDARE A COMPONENTELOR DIN OŢEL MARTENSITIC ALE TURBINELOR HIDRAULICE

STUDY ON REPAIR BY WELDING MARTENSITIC STEEL
COMPONENTS OF HYDRAULIC TURBINES
CA-6NM cast parts are frequently used in the manufacture of rotors and
turbines guiding equipment. CA-6NM material behaves better at casting and
improved weld ability compared to the stainless steel CA-15. During the
production process, rotor blades or their repairs hydraulic power operation have
identified four situations. These four cases have resulted to the design of
different welding repair technologies that are intended to meet the specific
conditions of each case.
Keywords: martensitic steel, welding, repairs, turbines
Cuvinte cheie: oţel martensitic, sudare, reparaţii, turbine
Descarcare text


25-55 EVALUAREA ANALIZELOR FIZICO – CHIMICE ÎN LABORATORUL DE ÎNCERCĂRI LA ULEIURILE MINERALE ELECTROIZOLANTE FOLOSITE PENTRU TRANSPORTUL CURENTULUI DE ÎNALTĂ TENSIUNE

EVALUATION OF PHYSICO-CHEMICAL ANALYSES IN THE LABORATORY FOR TESTS ON MINERAL OILS
USED AS CARRIERS OF ELECTRICAL CURRENT
OF HIGH VOLTAGE
Now you can use these types of equipment using mineral oil. Trying to
replace the equipment that I use SF6. MV SF6 insulated equipment for
overload lines with manual operating system, remote connection rod, steel pole
hot dressed, motorized operating mechanism, the operation of electric wiring,
cable network connection.
Keywords: power plants, gas SF6, autotransformers, oil analysis,
physicochemical characteristics, electrical equipment
Cuvinte cheie: centrale electrice, gaz SF6, autotransformatoare,
analize de ulei, caracteristici fizico-chimice, echipamente electrice
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25-54 MĂSURAREA ŞI AFIŞAREA TEMPERATURII DE LA UN ECHIPAMENT INDUSTRIAL CU SISTEM DE DEZVOLTARE CU MICROCONTROLER

MEASUREMENT AND DISPLAY OF TEMPERATURE FROM
INDUSTRIAL EQUIPMENT WITH THE DEVELOPMENT
SYSTEM WITH MICROCONTROLLER
In most industrial applications which used electrostatic precipitators that
have been used more than 30 years, their electrical equipment’s (i.e. power
supply sources, electric insulators etc.) are old in terms of measurements and
controls. Measurements and controls systems with a microcontroller can be
used at electrostatic precipitators for from thermal power stations. It presents
an opportunity to measure and display the temperature of electric insulator or in
a different part of power supplies.
Keywords: temperature, industrial, microcontroller, development system
Cuvinte cheie: temperatură, echipament industrial, microcontroler,
sistem de dezvoltare
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25-53 CIRCUITE BASCULANTE ASTABILE REALIZATE PE AUTOMATUL PROGRAMABIL PS-3 KLÖCKNER- MOELLER – Partea a II-a

BISTABLE TRIGGER CIRCUITS MADE ON PS-3 KLÖCKNERMOELLER
PROGRAMMABLE LOGIC CONTROLLER – II
The paper presents three variants of bistable trigger circuits with PS-3
(Klöckner-Moeller) programmable logic controller. They have in their
composition two electronic circuits with time-on delay circuits. For each bistable
trigger circuits present the principle accompanied by graphic representations of
the main signals of the bistable trigger circuits, the mode of operation of these
oscillators, and finally, the program achieved on PS-3 programmable logic
controller related signal generators.
Keywords: programmable, automatic changeover circuit, circuit time
astable, timing at actuator
Cuvinte cheie: automat programabil, circuit basculant astabil, circuit de
timp, temporizare la acţionare
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25-52 CIRCUITE BASCULANTE ASTABILE REALIZATE PE AUTOMATUL PROGRAMABIL PS-3 KLÖCKNER- MOELLER – Partea I-a

BISTABLE TRIGGER CIRCUITS MADE ON PS-3 KLÖCKNERMOELLER
PROGRAMMABLE LOGIC CONTROLLER – I
The paper presents three variants of bistable trigger circuits with PS-3
(Klöckner-Moeller) programmable logic controller. They have in their
composition two electronic circuits with time-on delay circuits. For each bistable
trigger circuits present the principle accompanied by graphic representations of
the main signals of the bistable trigger circuits, the mode of operation of these
oscillators, and finally, the program achieved on PS-3 programmable logic
controller related signal generators.
Keywords: programmable, automatic changeover circuit, circuit time
astable, timing at actuator
Cuvinte cheie: automat programabil, circuit basculant astabil, circuit de
timp, temporizare la acţionare
Descarcare text


25-51 ANALIZA PUTERILOR COMPLEXE ALE UNUI RECEPTOR TRIFAZAT

THE COMPLEX POWERS ANALYSIS OF A THREE-PHASE
LOAD
This paper presents the real unbalanced load and the powers
absorbed by it. It is considered the impedances with negative real part, in other
words generalized impedances. Also, taking into consideration the calculation
symmetrical components of impedances, a three-phase impedance system may
be divided into two parts: a balanced part and an unbalanced part. Afterwards,
the complex powers absorbed are calculated for the direct, inverse and
homopolar sequences. Then the diagram of the complex powers is deduced for
the real unbalanced load and are presented the conclusions. The bibliography
can be found at the end of the paper.
Keywords: three-phase, power complex receiver, generalized
impedance, symmetrical components, calculation of symmetrical components
Attenuation, the powers
Cuvinte cheie: receptor trifazat, putere complexă, impedanţă
generalizată, componente simetrice, componente simetrice de calcul ale
impedanţelor, diagrama puterilor
Descarcare text


25-50 ANALIZA PUTERILOR ACTIVE ALE UNUI RECEPTOR TRIFAZAT

THE ACTIVE POWERS ANALYSIS OF A THREE-PHASE LOAD
In this paper we consider a three-phase load and the absorbed powers
by it. We define the real unbalanced load, which has a balanced part and an
extremely unbalanced part. Using the complex power absorbed by the threephase
load, we make the actiwe powers analysis of it. Also, we construct the
energetical diagrams about the active powers circulation and are presented the
conclusions. In the end of the paper we indicate the references.
Keywords: three-phase, power complex receiver, active power,
generalized symmetrical components, impedance, calculation of symmetrical
components Attenuation, energy diagrams
Cuvinte cheie: receptor trifazat, putere complexă, putere activă,
impedanţă generalizată, componente simetrice, componente simetrice de calcul
ale impedanţelor, diagrame energetice
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25-49 CALCULUL CU ELEMENTE FINITE A PARAMETRILOR ŞI CARACTERISTICILOR GENERATORULUI ELECTRIC ASINCRON CU DOUĂ ÎNFĂŞURĂRI STATORICE

FINITE ELEMENT CALCULATION OF THE PARAMETERS
AND CHARACTERISTICS OF ELECTRIC GENERATOR
STATOR WINDINGS WITH TWO ASYNCHRONOUS
Induction generator with dual stator winding is very good for low power
and speed, wind and hydro power plant systems, because it has a good
controllability, low reactive power consumption, low cost and flexible
characteristics. In this paper is presented the 2D finite element method (FEM)
analysis, and parameters and characteristics.
Keywords: electrical generator stator windings, two asynchronous, low
speed, power and finite element analysis
Cuvinte cheie: generator electric asincron, două înfăşurări statorice,
putere şi turaţie reduse, analiză cu elemente finite
Descarcare text


25-48 CREŞTEREA PRODUCTIVITĂŢII DE ENERGIE ELECTRICĂ ŞI REDUCEREA PIERDERILOR PRIN GĂSIREA DE SOLUŢII OPTIME LA GENERATOARELE DE ENERGIE EOLIANĂ

INCREASE PRODUCTIVITY AND REDUCE ELECTRICITY
LOSSES BY OPTIMUM SOLUTIONS FOR WIND ENERGY
GENERATORS
Decentralized energy production, currently receiving a very important
development, applicable in various industries. It covers a huge range of power
from a few kW to tens of MW. What to do is to find as many injection points in
the low voltage network. In this article we present a detailed study of the
performance of energy systems to produce electricity by using wind energy and
optimization solutions to reduce costs.
Keywords: Energy, Wind Energy, Green Energy
Cuvinte cheie: energie, centrale eoliene, energie verde
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25-47 OBSERVAŢII PRIVIND INFLUENŢA CÂMPULUI DE VITEZE ASUPRA GEOMETRIEI PALETELOR TURBINELOR EOLIENE CU AX ORIZONTAL

NOTES ON THE INFLUENCE OF SPEED FIELD ON
THE GEOMETRY OF HORIZONTAL AXIS WIND TURBINES
Unlike hydraulic turbines, wind turbines operate ”in open apparatus”.
Thus, the field of velocities and pressures has direct influence on the operation
of the turbine. The paper presents an analysis of the influence of the speed
field on the geometry of the blades of horizontal axis wind turbines.
Keywords: wind turbines, geometry, optimization
Cuvinte cheie: turbine eoliene, geometrie, optimizare
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25-46 TESTAREA LA SARCINĂ STATICĂ DISTRIBUITĂ A PALETELOR DE TURBINĂ EOLIANĂ DE MICĂ PUTERE

TESTING AT DISTRIBUTED STATIC LOADS OF THE ROTOR
BLADES OF LOW POWER WIND TURBINES
This paper presents a study on distributed static load testing of 5 kW
wind turbine blades. There have been done tests at distributed static loads on
five blades of the rotor designed and installed in an Alba county site. It has also
been investigated the behaviour at the same load type and for the same blade,
using a finite element analysis method. There were drew conclusions about the
comparison of results obtained by the two methods.
Keywords: low power wind turbines, Finite Element Analysis, load,
stress
Cuvinte cheie: turbine de vânt de mică putere, paletă, metoda
elementelor finite, forţe aerodinamice, momente, tensiuni, rezistenţă mecanică
Descarcare text


25-45 STUDIU DE SOLUȚIE PRIVIND RACORDAREA UNEI CENTRALE ELECTRICE EOLIENE DE 20 MW partea a III-a

ETUDE DE RACCORDEMENT D’UNE FERME
EOLIENNE DE 20 MW – Partie III de la
L’article présente les solutions possibles de raccordement au système
électro énergétique national (SEN) de la ferme éolienne de Nufăru, dép. de
Tulcea ayant une puissance installée de 20 MW. Les calculs de circulation des
puissances sont effectués sur le réseau à N éléments et les réseaux à N-1
éléments, en fonction des contingences prises en compte.
Mots clés : parcs éoliens, puissance
Cuvinte cheie: parcuri eoliene, circulaţii de puteri
Descarcare text


25-44 STUDIU DE SOLUȚIE PRIVIND RACORDAREA UNEI CENTRALE ELECTRICE EOLIENE DE 20 MW partea a II-a

ETUDE DE RACCORDEMENT D’UNE FERME
EOLIENNE DE 20 MW – Partie II
L’article présente les solutions possibles de raccordement au système
électro énergétique national (SEN) de la ferme éolienne de Nufăru, dép. de
Tulcea ayant une puissance installée de 20 MW. Les calculs de circulation des
puissances sont effectués sur le réseau à N éléments et les réseaux à N-1
éléments, en fonction des contingences prises en compte.
Mots clés : parcs éoliens, puissance
Cuvinte cheie: parcuri eoliene, circulaţii de puteri
Descarcare text


25-43 STUDIU DE SOLUȚIE PRIVIND RACORDAREA UNEI CENTRALE ELECTRICE EOLIENE DE 20 MW partea I-a

ETUDE DE RACCORDEMENT D’UNE FERME
EOLIENNE DE 20 MW – Partie I-la
L’article présente les solutions possibles de raccordement au système
électro énergétique national (SEN) de la ferme éolienne de Nufăru, dép. de
Tulcea ayant une puissance installée de 20 MW. Les calculs de circulation des
puissances sont effectués sur le réseau à N éléments et les réseaux à N-1
éléments, en fonction des contingences prises en compte.
Mots clés : parcs éoliens, puissance
Cuvinte cheie: parcuri eoliene, circulaţii de puteri
Descarcare text


25-42 REDUCTOARELE DE PRESIUNE DIN AMENAJĂRILE HIDROTEHNICE

THE PRESSURE REDUCERS FROM HYDROTECHNICAL APPLIANCES
This paper presents two types of pressure reducers which can be
used for different interior diameters of the pipes. There are presented all the
working characteristics for every reducer. The models presented are very
simple and inexpensive so that the final results could be very good.
Keywords: pressure reducers, working characteristics, hydro technical
appliances
Cuvinte cheie: reductoare de presiune, caracteristici de funcționare,
amenajări hidrotehnice
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25-41 ANALIZA SIGURANŢEI ÎN FUNCŢIONARE A STAŢIILOR ELECTRICE

RELIABILITY STUDY OF ELECTRIC POWER STATIONS
The paper treated the main aspects regarding the reliability of
electric stations from power electric energy system of Electrica S.A. Resita,
with modern techniques for diagnosis and maintenance. It has been
considered useful to treat the electric energy system with equivalent
structural diagram method for reliability indicators calculus using the
MathCAD medium.
Keywords: reliability, method, equivalent element, indicators
Cuvinte cheie: fiabilitate, metodă, element echivalent, indicatori
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25-40 EXPLOATAREA POMPELOR VOLUMICE CE ACŢIONEAZĂ INSTALAŢIILE DE SIGURANŢĂ ALE BARAJELOR

EXPLOATATION OF VOLUMETRIC PUMPS WHICH
ACT DAM SAFETY SYSTEMS
Exploitation means all operations which are performed in order to
efficiently use the parameters of equipment or a machine in order to maintain
their values as acceptable for a period of time. Experience shows that often
because major malfunctions, found during exploitation, were due to failure or
not taking into account the indications that seem usually unimportant.
This article presents important aspects of operating pumps that
discharge valve installation equips bottom dam Motru applicable for the range
of volumetric pumps that equip hydraulic installations. Following situations were
analysed: replacement pumps less than 30 years in operation, adapting the
existing hydro plant, adjustments made for putting into service and operation.
Key words: axial-piston pump volume, exploitation, life expectancy, ass
wipe
Cuvinte cheie: pompă volumică cu pistoane axiale, exploatare, durată
de viață, golire de fund
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25-39 STANDARDELE ÎN SPRIJINUL SISTEMELOR DE MANAGEMENT AL ENERGIEI ŞI AL SURSELOR REGENERABILE DE ENERGIE ELECTRICĂ CU UTILIZAREA ENERGIEI POTENŢIALE A APEI Partea a II-a

STANDARDS SUPPORTS THE ENERGY MANAGEMENT
SISTEMS AND THE RENEWABLE ENERGY SOURCES
USING POTENTIAL ENERGY OF THE WATER – Part II
Renewable energy and energy efficiency of the industrial systems are
two main objectives that lead to improve security of supply and to reduce the
primary energy consumption.
The technical committees are structured on the technical
standardization profile, regarding security requirements, measurement
techniques, attempts to reception and automation systems (based on a uniform
terminology) to obtain electricity using the energy of water in the hydraulic
turbine and the energy of the tidal and the waves.
The Energy management and the energy strategy improve energy
efficiency and reduce energy consumption. This paper presents European and
International standardization activity regarding these fields.
Keywords: management, energy, benchmarking, audit, renewable
energy sources, hydraulic turbines, marine energy, wave, tidal, water current
Cuvinte cheie: management, energie, analiza comparativă, audit,
surse regenerabile de energie, turbină hidraulică, hidrocentrală, energie
marină, valuri, maree, curent de apă
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25-38 STANDARDELE ÎN SPRIJINUL SISTEMELOR DE MANAGEMENT AL ENERGIEI ŞI AL SURSELOR REGENERABILE DE ENERGIE ELECTRICĂ CU UTILIZAREA ENERGIEI POTENŢIALE A APEI Partea I-a

STANDARDS SUPPORTS THE ENERGY MANAGEMENT
SISTEMS AND THE RENEWABLE ENERGY SOURCES
USING POTENTIAL ENERGY OF THE WATER – Part I
Renewable energy and energy efficiency of the industrial systems are
two main objectives that lead to improve security of supply and to reduce the
primary energy consumption.
The technical committees are structured on the technical
standardization profile, regarding security requirements, measurement
techniques, attempts to reception and automation systems (based on a uniform
terminology) to obtain electricity using the energy of water in the hydraulic
turbine and the energy of the tidal and the waves.
The Energy management and the energy strategy improve energy
efficiency and reduce energy consumption. This paper presents European and
International standardization activity regarding these fields.
Keywords: management, energy, benchmarking, audit, renewable
energy sources, hydraulic turbines, marine energy, wave, tidal, water current
Cuvinte cheie: management, energie, analiza comparativă, audit,
surse regenerabile de energie, turbină hidraulică, hidrocentrală, energie
marină, valuri, maree, curent de apă
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