Revista HIDRAULICA | HIDRAULICA Magazine

ISSN 2343–7707 ; ISSN-L 1453-7303

CURRENT ISSUE – HIDRAULICA Magazine No. 1/2018


Analysis of Temperature Resistance of Pressurized Cylindrical Fuel Tanks
Authors: Mihai ŢĂLU, Ștefan ŢĂLU

In this study, an approach based on Finite Element Modeling (FEM) was applied to analyze the performances of three different pressurized cylindrical fuel tanks with the same lateral cover, but with various head covers geometries. A specific mechanical and thermal model based on FEM was developed. A particular analysis of temperature resistance was carried out, to define specific key performance indicators and to determine (read more)


Using the Pressure Intensifiers in Hydraulic Units of Heavy Duty Machine Tools
Authors: Dan PRODAN, Anca BUCUREȘTEANU
 

This paper presents some applications of the pressure intensifiers used in the hydraulic units of the clamping/unclamping systems and unloading systems for the guideways of HBM and GANTRY type heavy duty machine tools. The paper makes a comparison between the systems with and without pressure intensifiers. There are presented mathematical models for the pressure intensifiers and the results obtained after ... (read more)


Improving Roughness Using Toroidal Milling for Complex Surface Processing
Author: Andrei OȘAN

The paper aims to study the processing of complex and convex surfaces using a cutting tool in a milling radius called toroidal end milling in terms of roughness. Roughness presents important influences on machine parts and not only be in operation contact surfaces are either fixed or mobile. This paper includes a series of 11 experiments in which different regimes are tested with the main purpose of finding the optimum regimen for the work to be subjected to the toroidal milling using the roughness value Ra and Rt as the comparison criterion. For roughness determination, the TR200 is used as a … (read more)


Design and Optimization of Pressurized Toroidal LPG Fuel Tanks with Variable Section
Authors: Mihai ŢĂLU, Ștefan ŢĂLU

This study addresses the design and optimization of the pressurized toroidal LPG fuel tanks with variable section used in automotive industry based on the finite element analysis (FEA) approaches, to model both thermal and mechanical processing conditions. To define specific key performance indicators and to determine the optimal form of toroidal LPG fuel tank with the minimum stress state and linear deformation was applied a mathematical and mechanical foundation for the design and optimization. Computer aided investigations are carried out using … (read more)


Fault Tree Analysis Used in Offshore Industry
Authors: Mariana PANAITESCU, Fănel-Viorel PANAITESCU, Ionuț VOICU,
Laurențiu-George DUMITRESCU

Fault Tree Analysis is one of the engineering tools that provide a systematic and descriptive approach to the identification of systems under risk. Probabilistic Risk Assessment (PRA) is a method to determine the reliability of a system based on the probability of component(s) and/or system(s) failure. Fault Tree Analysis (FTA), which is a part of PRA, provides a method for determining how failures can occur both quantitatively and qualitatively. In this paper we present the FTA for offshore facility: safety flow chart of offshore production facility, fault tree diagrams for … (read more)


Statistical Analysis of the Pollution of a Hydraulic Oil Based on the Evolution of the Filter Clogging on the Pressure Pipe
Authors: Mounir GAHGAH, Azzedine BOUZAOUIT 

We present in this paper the results of an experimental study conducted on the analysis of the influence of clogging of a hydraulic filter, installed on the discharge pipe of a variable displacement pump, the operating pressure is 210 bar. The pump is used to supply hydraulic power to a finisher in the rolling mill at the iron and steel complex in Algeria. In this context, we tested the filter retention efficiency, whose mesh size of the filter element is 15 μm. The influence of the service time and consequently the number of pollutant particles retained per filter on the singular pressure loss ΔP of the filter were characterized. A statistical analysis conducted on the representative sample of ΔP values, followed by … (read more)


Numerical Simulation of Thermal Processes Occurring at Testing Hydrostatic Pumps in Cavitation Mode
Authors: Alexandru-Daniel MARINESCU, Alexandru-Polifron CHIRIȚĂ, Corneliu CRISTESCU, Carmen-Anca SAFTA

This article refers to the use of infrared thermography in the predictive maintenance of hydraulic drive systems. Based on experimental research on the temperature evolution in a hydraulic system which operates in cavitation mode, a numerical simulation model was built. The numerical simulation results are compared with experimental measurements in the points of interest of the hydraulic diagram versus numerical simulation model. The results obtained show that infrared thermal imaging camera procedure can be used in the limit of … (read more)


Theoretical Aspects regarding the Pressure Safety Valves Operation within a Hydraulic Circuit
Author: Fănel Dorel ȘCHEAUA

Construction and agricultural machinery and equipment drives are currently accomplished by means of high-performance hydraulic and pneumatic systems through which difficult workloads are easily performed. Such systems have evolved over time, being indispensable from the basic functional machinery aggregate. In research-driven development there is a continuous increase in working power based on the increase of working pressure values ​​inside the hydrostatic circuits used. Primary components represented by pumps, motors, distributors need protection during the circuit operation at medium and high pressure values. This overpressure protection is carried out by means of safety valves or pressure valves that are able to send part of the working fluid flow rate to the plant tank adjusting the pressure to a value at which (read more)


From Human-Environment Interaction to Environmental Informatics (I): Theoretical and Practical Implications of Knowledge-Based Computing
Authors: Bogdan CIORUȚA, Mirela COMAN, Alin-Andrei CIORUȚA, Alexandru LAURAN

During recent decades the stirring up of the processes of globalization, practically in all spheres of present day civilization, has aggravated the society and brought numerous problems resulting from human-environment interactions. To overcome these problems, it is necessary to develop and adopt new concepts and techniques to manage the changes occurring on the Earth’s ecosystem. For this, application of information and communication technology via Environmental Information Systems (EISs) – as integrated part of Environmental Informatics (EI) – is the best option. This paper deals with new and interactive approach to process, analysis and synthesis of environmental systems using various IT applications, so we could underline that … (read more)

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