ISSN 2343–7707 ; ISSN-L 1453-7303

HIDRAULICA Magazine No. 1 / 2016

Hidraulica no.1/2016

Numerical Investigation of Unsteady Flows Using OpenFOAM
Author: Alin ANTON

In this paper OpenFOAM is used for the numerical investigation of the unsteady flow in a well known numerical benchmark. Von Karman vortex street is obtained in a flow of water past a square cylinder. The results are validated against experimental and numerical investigations from the literature using the drag coefficient. The bazaar-style development of the OpenFOAM toolkit and the principles of Free Software are confirmed to be valid even for …. (read more)

Modeling and Simulation of Conical Poppet type Relief Valve with Damping Spool
Authors: Basavaraj V. HUBBALLI, Vilas B. SONDUR

This paper deals with the simulation of poppet type pressure relief valve with damping spool to analyze transient response. Mathematically explained the performance characteristics of this valve based on original research carrying out on the compound pressure relief valve and related to hydraulic pressure control valve. Pressure control valves allow establishing sequences in hydraulic operations via …. (read more)

Considerations on Flow Regeneration Circuits and Hydraulic Motors Speed Variation at Constant Flow
Authors: Teodor Costinel POPESCU, Alina Iolanda POPESCU, Alexandru MARINESCU

The material shows a brief summary of simple practical applications of hydraulic drive systems that work on three principles: technology of regeneration of hydraulic motors feed flow, variation in steps of hydraulic motors speed at constant flow and control of vertical displacement speed of inertia loads. These applications have good energy efficiency, low price, high reliability and they are used to drive mechanisms that operate in several working phases, characterized by …. (read more)

Optimization of Axial Wind Turbines Operation
Author: Mircea BĂRGLĂZAN

The operation of horizontal axial wind turbines was diversified through their applications in aero-energetic of variable speed of rotation. These situations are investigated and optimized in function of wind velocity, as intensity. Results are useful for wind power plants Marga and Ciugud designed and realized by … (read more)

Considerations on Energy Losses in Hydraulic Drive Systems
Authors: Corneliu CRISTESCU, Catalin DUMITRESCU, Genoveva VRÂNCEANU, Liliana DUMITRESCU

The article presents some considerations on energy losses in hydrostatic drive systems, identifying the elements and specific places where flow and pressure losses occur. Some considerations are made on flow regimes and calculation relations are presented for assessing the pressure and flow losses; also, on an example of hydrostatic drive system, there is assessed energy dissipation and …. (read more)

Functional Description of a Hydraulic Throttle Valve Operating inside a Hydraulic Circuit
Author: Fănel Dorel ȘCHEAUA

Nowadays the global manufacturers for industrial and mobile equipments offer products containing advanced hydraulic systems by means of which are accomplished the multiple tasks imposed by the designers in a convenient and easy manner. The hydraulic systems are comprised of components of last generation that are able to circulate the working fluid (mineral oil) at high values of pressure and considerable speed through their proper circuit. Besides the hydraulic pump and engine as the primary components of the hydraulic circuit there are also the pressure and flow control components necessary to …. (read more)

Fertilizer Injection Device
Authors: Gheorghe SOVAIALA, Sava ANGHEL, Gabriela MATACHE, Alina POPESCU, Petru CARLESCU, Nicolae TANASESCU

The fertilizer injection device is a component of the equipment for fertigation of horticultural crops (the main vegetable species cultivated in protected areas, and respectively tree species and shrubs) used at works in aggregate with drip irrigation and micro sprinkling systems.
The injection device (type double diaphragm pump with hydraulic control) developed under the PN-II-PT-PCCA-2013-4-0114 – Contract no. 158/2014 in Experimental Model phase, offers a number of advantages compared to … (read more)

Alternating Flow Hydraulic Generator for Water Jet Cutting Systems
Authors: Ioan-Lucian MARCU, Cornel CIUPAN

The paper describes new approaches regarding the water jet machining systems. There are presented some aspects of the design possibilities of the water jet cutting head in the context in which the main hydraulic power supply is not a conventional one, but one who can provide directly an alternating flow, considering also the involved disadvantages of this solution.
The second part present a some concepts regarding the design of an alternating flow hydraulic generator, and details regarding the functioning conditions which …. (read more)

A Review of Heat Engines
Authors: Aman GUPTA, Sunny NARAYAN

  Engines are common engineering devices which have become essential to the smooth running of modern society. Many of these are very sophisticated and require infrastructure and high levels of technological competence to ensure their correct operation, for example, some are computer controlled, others require stable three phase electrical supplies, or clean hydrocarbon fuels. This project focuses on the use of novel Stirling engine which can be used to pump water up to certain distance without use of …. (read more)

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