This paper presents the using criterions to estimate the behavior and
cavitațional resistance of materials. The materials were testing in laboratory
installations. Also are analyses how can it apply and calculate.
Cuvinte cheie: cavitație, rezistență, criteriu, parametru, viteza de
eroziune cavitațională
Keywords: cavitations, resistance criteria, parameters, cavitational
erosion rate
The index tests performed to double regulated turbines are used to
determine operating characteristics, to check on cam operation, to check power
guarantee, the efficiency etc.
Cuvinte cheie: probe index, hidroagregat, turbină cu dublu reglaj,
randamentul turbinei, cădere, debit, aparat director, rotor
Keywords: index tests, hydro unit, double regulated turbine, turbine
efficiency, head, discharge, wicket gates, runner
The paper analyses the wave energy capture and conversion with
hydro pneumatic equipments.
Main stages and activities of the project, results
a) A relevant study has been accomplished which analyzed the
hydro-meteorological conditions in the western Black Sea. Also it has been
made a documented presentation of the types of hydro plants suitable for
efficient conversion of wave energy in this area.
b) An experimental model of small-scale power plant driven by
waves has been designed and executed. Also, it has been performed
experiments on this model and on a specialized channel for wave simulation.
Hydropneumatic and energetic characteristics has been obtained and similarity
criteria for reporting results scale and choosing the best construction were
developed.
c) Building plans for a full scale hydro power plant were developed.
The generator which converts the wave energy into electrical energy was also
designed and made.
d) Experiments were conducted on a stand in a wind tunnel to test
the electrical generator, which required the devise and development of specific
support and aligning elements. The turbine was gradually loaded by connecting
to the shaft an electrical generator having a variable resistive load at output.
e) Determinations were performed in air velocity range of 5-20 m/s,
and characteristics of mechanical power have been extrapolated by specific
similarity criteria up to 50 m/s. It was concluded that the conversion unit is
compatible with a maximum power of 3.6 kW at an air velocity of 50 m/s
f) It has been developed technical documentation for construction
109
and assembly of micro hydro power plant.
g) There were carried out analytical calculations and computer
simulations to demonstrate the functionality of the model to illustrate the
phenomenology of the flow in the oscillating column, the dynamic behavior of
the turbine, and the correlation with experimental results.
Cuvinte cheie: microelectrocentrale, resurse regenerabile, conversia
energiei, valuri
Keywords: micro power plant, renewable resources, energy
conversion, wave
At low power wind turbines blade end is free. The paper shows the
negative influences of finite span on performance profiles. It is made a critical
analysis of application Prandtl model for finite span wing at low power wind
turbines. The paper introduces a new method for calculating certain
adjustments based on Prandtl model.
Cuvinte cheie: turbine de vânt de mică putere, modelul Prandtl,
anvergura finită, coeficient de portanţă, coeficient de rezistenţă, coeficientul de
portanţă indus şi coeficientul de rezistenţă indus.
Keywords: low power wind turbines, Prandtl model, scale finite lift
coefficient, drag coefficient, lift coefficient and induced drag coefficient induced
The paper presents a contribution to the aerodynamic body of
revolution movement trajectories in the thin atmosphere. As a particular case,
the paper refers to flying projectiles and missiles, to customize linearization
stationary movements around thin bodies of revolution.
Cuvinte cheie: proiectil, rachetă, potenţialul vitezelor, numărul Mach,
unghi de atac
Keywords: projectile, rocket, potential speed, Mach number, angle of
attack
This paper presents some features of evolutionary parameters on fluid
flow through the ejector gas dynamics. Ejectors are devices with wide
applicability gas dynamical in the technical field and especially in the military.
Cuvinte cheie: ejector, camera de amestec, parametri gazodinamici,
camera de amestec, coeficient de ejecţie, fluid antrenat, fluid de antrenare
Keywords: ejector, mixing chamber, gas dynamical parameters, the
mixing chamber, ejection coefficient, fluid driven fluid drive
The paper presents the components and the behavior of a hydraulic
axe, used to simulate the yaw mechanism of a wind turbine. Are presented,
synthetic calculations for sizing stand and the main experimental results
obtained. Has been carried out static and dynamic control and record the
results being achieved with the computer attached to the stand.
Cuvinte cheie: turbine de vânt, reglare, model matematic, încercări
statice, încercări dinamice
Keywords: wind turbine, control, mathematical model, static testing,
dynamic testing
This paper presents the behaviour of a micro-hydro unit equipped with a
small cross-flow turbine (turbine calculated power is lass than PT=10 kW),
depending on the opening angle of the guiding paddle, at same amount of
water falling height. The tests and measurements were made at Hydro
Engineering SA Reşiţa hydraulic laboratories, with specialized equipment.
Cuvinte cheie: comportament, randament, 10 kW, unghi de deschidere,
paletă
Keywords: behaviour, output, 10 kW, opening angle, wide
This second paper presents the behaviour of a micro hydro unit
equipped with a small cross-flow turbine, depending on the height of fall of
water, at various opening angle of the guiding paddle. The tests and
measurements (as in the previously case) were made at Hydro Engineering SA
Reşiţa hydraulic laboratories, for several values of the height of fall of water.
Cuvinte cheie: comportament, randament, 10 kW, înălţimea de cădere,
paletă
Keywords: behaviour, output, 10 kW, falling height, palette
Établir des relations pour permettre l`application des résultats des
testes d`érosion de la cavitation, d`un appareil a l`autre, représente une
continue préoccupation des chercheurs. À cet égard, l`ouvrage offre un model
de cet type de relation, mais qui, dans cette phase, permettre la corrélation
d`un petit nombre de matériaux, testé en Laboratoire de Machines
Hydrauliques de Timisoara, Gdansk et Michigan.
Cuvinte cheie: rezistența la cavitație, parametri aparat vibrator, relații
de corelare
Mots-clés: résistance à la cavitation, les paramètres des appareils
vibrants, des relations de corrélation
This paper presents boundary element method (BEM), with linear
elements, for the numerical simulation of ideal incompressible fluid, for a
reversible cascade”S” axial profiles. BEM apply for Laplace’s equation
depending on flow and hydrodynamic field, speed and pressure are obtained,
inside of domain analysis.
Cuvinte cheie: elemente liniare, BEM, ecuaţia lui Laplace, puncte
unghiulare
Keywords: linear elements, BEM, Laplace equation, angular points
Globalization is a new challenge for small and medium-sized
enterprises. On one hand pose a threat, because new companies are going to
enter the domestic market, but, on the other hand, represent an opportunity to
enter the new emerging and growing markets.
In order to win this challenge SMEs must focus on the inter-network
connection; in fact, is well recognized that SMEs forming networks can improve
the efficiency and effectiveness absolutely necessary to win the globalization
battle.
Cuvinte cheie: SIAD, IMM, tablou de bord, indicatori economicofinanciari
Keywords: DSS, SME, dashboard, financial-economical indicators
The present paper regards elements about safety management
system and maintenance in civil and military aeronautical field. All organisations
must correlate the minimum risk with higher performance in their specific
activity.
Cuvinte cheie: de întreţinere, de gestionare a riscurilor, de siguranţă,
costuri
Keywords: maintenance, risk management, safety, costs
Utilizarea unui dinamometru la alte trepte de sarcină decât cele la care
a fost etalonat reclamă aplicarea metodei interpolării valorilor măsurate. În
lucrare se propun relații de definire a abaterilor de interpolabilitate aferente
acestui procedeu, cu aplicații la un set de 9 dinamometre ovale tip PGH.
Wenn Kraftmessbügel bei Werten verwendet werden die zwischen
den beim Eichen eingestellten Kraftstufen liegen, wird üblicherweise die
Methode des Interpolierens angewendet. In vorliegender Arbeit werden
Beziehungen für die Bestimmung der Interpolierbarkeitsabweichung
vorgeschlagen, die an Hand von Messungen an 9 ovalen Kraftmessbügel des
Typs PGH erläutert werden.
Cuvinte cheie: dinamometre1, interpolarea2 valorilor măsurate,
imprecizia metodei
Schlüsselwörter: Dynamometern, Interpolierung der messtechnischen Kenngrösse, Ungenauigkeit der Methode
Articolul prezintă un sistem de achiziţie şi de prelucrare pentru tensiuni
şi curenţi de la o rețea electrică de joasă tensiune, o structură dezvoltată pentru
a fi integrată într-un sistem complex de gestionare a energiei.
Pentru a asigura o flexibilitate sporită, sistemul este modular şi este complet
personalizabil de software. Toate componentele sunt module compatibile, toate
semnalele de intrare/ieşire sunt standardizate (0 .. 100V AC, 0 .. 5A AC şi 4 ..
20 mA – semnal unificat). Toate modulele sunt interschimbabile, tipul de
configuraţie de intrare se introduce uşor prin aplicarea interfaței prietenoase.
Sistemul constă dintr-un set de semnal, un card de achiziţie de date şi un
calculator personal. Toate conditionat au ieşire în semnal unificat, şi placa de
achiziţie de date comunică cu computerul prin intermediul unui port serial
(RS232 sau în cazul în care există un risc ridicat de interferenţă, RS485). Pe
PC-ul se execută o aplicaţie cu interfaţă prietenoasă, responsabil de
configurarea sistemului şi de stocare a datelor.
Cuvinte cheie: achiziții de date, de semnal unificat, de control a
tensiunii
Keywords: data acquisition, unified signal, voltage monitoring
In this paper we shall present such the numerical solving as the
experimental test of the viscous liquid three dimensional flow through the
clearance with and without baffle plate of the hydraulic turbo machine
labyrinths, considering the ring curvature by using the flow equations written in
the cylindrical trihedral coordinates.
We present also the stability of the numerical solution and the specific
boundary conditions to the posed problem, as well as the installation to
visualize the appearance of Sir Geoffrey Taylor’s whirls.
Cuvinte cheie: debit tridimensional, fluxurile de lichide vâscoase,
fluxuri hidraulice prin labirinturi/strângeri ale turbo-maşinilor
Keywords: three-dimensional flow, viscous liquid flows, flow through
the hydraulic turbo machine tightening labyrinths