ISSN 2343–7707 ; ISSN-L 1453-7303


Hidraulica no 2/2024Modeling and Simulation of the Hydraulic Clamping/Unclamping Systems Using Hydro-Pneumatic Accumulators

This article highlights some methods for determining the optimal accumulator for the hydraulic units with accumulators used in the locking and clamping/unclamping systems for machine-tools. The mathematical models and the results of the simulations carried out for designing such units are shown below. The results of the research can also be applied in the case of … (read more)

The Laser Treatment’s Impact on the Surface Topography of MONEL® Alloy 400, used in the Manufacturing of Marine Equipment Components
Authors: Ștefan ŢĂLU, Kipkurui RONOH, Dinara SOBOLA

In the study, the authors investigated the effects of picosecond laser ablation on the surface topographies of MONEL® alloy 400, used in the manufacturing of marine equipment components (such as pumps, valves, fixtures and fasteners). The experimental methodology involved preparing the material through grinding, polishing, and cleaning before subjecting it to picosecond laser ablation using specific parameters. The laser processing was carried out to create square ablated cavities on the alloy surface. The impact of the laser treatment on the surface condition of the alloy was assessed through … (read more)

Experimental Measurement of Functional Parameters for a Tesla Turbine
Authors: Răzvan-Ionuț TĂNĂSESCU, Dragoș-Ionuț SBURLAN, Adrian-Sebastian UNGUREANU, Ștefan-Mugur SIMIONESCU

A small-scale experimental set-up was designed and built, consisting of a Tesla turbine and electric generator, with casing, consumer and measurement devices. Experimental measurements were carried out, regarding the working performance of the turbine at different air inlet pressures. The other parameters measured were the inlet air velocity, the rotational speed and the output electrical power. The results were discussed and explained through … (read more)

Modification of the Cavitation Erosion Resistance of Aluminum Alloy 2017 A by 12 Hours Duration of the Artificial Ageing Heat Treatment at 140°C 
Authors: Ilare BORDEAȘU, Brândușa GHIBAN, Alexandru Nicolae LUCA, Dorin BORDEAȘU, Cristian GHERA, Cornelia Laura SĂLCIANU, Daniel Cătălin STROIȚĂ

Aluminum-based alloys are known for their applications in most fields, due to their physical-mechanical properties and their technological capability to lend themselves to the realization of various parts, with geometrical configurations ranging from simple to complex. These parts include those working in hydrodynamic flow fields, characterised by certain degrees of destruction by erosion created by microjets and shock waves. Such parts are the propellers of motor boats, the impellers of household pumps, radiators and pumps in the cooling system of motor vehicles. As erosion causes the surface of the part to change, causing it to fail, research is currently being developed to increase service life by … (read more)

Modelling and Simulation of Hydraulic Circuits Using 4/2-Way Hand-Lever Valves
Authors: Mihai DIACONU, Elena Gabriela CURCĂ, Lidia CALANCEA, Tiberiu AXINTE, Camelia PASCU, Iulia TOMOZEI

The paper presents an overview of the efficiency for a hydraulic circuit with 4/2-way hand-lever valves. Thereby in this article we are studying three hydraulic circuits which contain 4/2-way hand-lever valves. The first hydraulic circuit contains the following devices: pump unit, tank, 4/2-way hand-lever valve, throttle valve, double acting cylinder (Dou 1-1). The second hydraulic circuit contains the following components:  pump unit, tank, 4/2-way hand-lever valve, pressure relief valve, double acting cylinder (Dou 2-1), and 2-way flow control valve. The last circuit, which is actually (read more)

Considerations regarding the Behaviour of X12CrMoS17 and X22CrNi17 Steels to the Cavitation Erosion
Authors: Lavinia Mădălina MICU, Ilare BORDEAȘU, Daniel OSTOIA, Robert PARMANCHE, Alexandru Nicolae LUCA, Cristian GHERA, Corneliu Eusebiu PODOLEANU, Cornelia Laura SĂLCIANU

The paper presents the results of the cavitational erosion research carried out on two stainless steels intended for the manufacture of parts strongly subjected to cavitation, such as the vanes and rotors of hydraulic turbines and pumps. In accordance with the new trends, to reduce carbon below 0.1%, for both categories the carbon content was kept at the value of 0.038%. The researches are carried out in the Cavitation Erosion Research Laboratory of the Politehnica University of Timisoara, on the magnetostrictive vibrating device with a nickel tube. The behaviour and resistance to cavitation erosion are evaluated based on  (read more)

Hurricane Otis Forensic Analysis Effects on Acapulco Bay: Identification of Variables Causing Damage

The devastating impact of Hurricane Otis, a Category 5 storm that hit Acapulco Bay, Mexico, in October 2023, highlighted the importance of conducting in-depth forensic hydrology analysis. With sustained winds close to 265 km/h, the storm caused rapid urban flooding and landslides exacerbated by an extraordinary 190 mm of rainfall within 4 hours. This event emphasizes the critical link between water dynamics and climate change. By examining the hydrological factors behind such extreme coastal weather events, this study sheds light on (read more)

Numerical Simulation of Drying Equipment for Vegetal Matter with Automatic Process Control and Moisture Estimation by means of a Neural Network
Authors: Alexandru-Polifron CHIRIȚĂ, Gabriela MATACHE, Adriana Teodora MUSCALU

This study presents the development and validation of a comprehensive numerical simulation model for drying equipment designed for vegetal matter, utilizing automatic process control and moisture estimation through a neural network. The system, modeled in AMESim, includes a TLUD (Top-Lit UpDraft) gasifier as the heat source, an air flowrate regulation mechanism controlled by butterfly valves, and a drying chamber. A PID (Proportional-Integral-Derivative) controller with autotuning capabilities manages the air flowrate to maintain the desired drying temperature. Additionally, a neural network, trained with experimental data, estimates (read more)

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