hydraulic power
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2022 ◽  
Vol 24 (1) ◽  
pp. 152-164
Author(s):  
Vrushabh A.Madnaik ◽  
◽  
V.R. Naik ◽  

Broaching machine is mainly developed for special purposes where cycle times are less and number of job quantity is very high. Only at such points development of broaching machine is justified. Design of such broaching machine is totally customizable. This paper discuss about frame design of machine, selection of guideways, design of hydraulic power pack for hydraulic operated machine and also selection of various cylinders, pipe fittings, mandrels, pump, motor, etc. So, main purpose of this paper is designing the broaching machine which includes all its components. This paper focuses on selection of bought out parts too.


2021 ◽  
Vol 29 (1) ◽  
pp. 55-71
Author(s):  
Vladimir V. Tetelmin

Fossil fuel energy and increase in concentrations of greenhouse gases in the atmosphere cause global climate change. In pursuance of the goals of the Paris Agreement, the global power industry must switch a significant part of fuel energy production to renewable energy production. The expected share of various sources in the global power industry by the end of the 21st century is provided. However, the limited possibilities of the biosphere make the current level of energy production from renewable sources nearly impossible. The most preferable scenario is proposed to reduce global carbon dioxide emissions by reducing the use of coal by 170 million tons per year, which will ensure a corresponding reduction in emissions by 620 million tons per year and the achievement by 2050 of the material balance of carbon in the emission - flow system. Under the most preferable scenario, it will be necessary to commission alternative replacement powers of about 160 GW per year; at the same time, the average global temperature will additionally rise by 0.6 С compared to the current one. The prospects and advantages of the development of the Russian hydraulic power industry as an environmentally and economically efficient alternative to coal projects are considered. In the emerging reality, Russian hydraulic power companies are advised to determine their ambitious share of the Russian quota for reducing emissions and commissioning 30 GW of replacement hydraulic power capacities by 2050 with additional electricity generation of up to 120 TWh per year.


Information ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 512
Author(s):  
Alexander Mitov ◽  
Tsonyo Slavov ◽  
Jordan Kralev

The impossibility of replacing hydraulic drives with other type drives in heavy duty machinery is the main reason for the development of a system for controlling hydraulic power steering. Moreover, the need for remote automatic control of the steering in specific types of mobile machinery leads to significant scientific interest in the design of embedded systems for controlling electro-hydraulic steering units. This article introduces an approach, which has been developed by authors, for robust stability and robust performance analysis of two embedded systems for controlling electro-hydraulic power steering in mobile machinery. It is based on the suggested new more realistic “black box” SIMO model with output multiplicative uncertainty. The uncertainty is obtained by parameters confidence interval and Gauss approximation formula. The embedded control systems used a linear-quadratic Gaussian (LQG) controller and H∞ controller. The synthesis of the controllers was performed on the basis of a nominal part of an uncertainty model. Robust stability and robust performance analyses were performed in the framework of a so-called structured singular value, μ. The obtained theoretical results were experimentally approved by real experiments with both of the developed control systems, which were physically realized as a laboratory test rig.


2021 ◽  
Author(s):  
Nur Alom ◽  
Bikash Kumar Sarkar

Abstract Cross-flow hydro turbines (CFHTs) are generally used in micro hydraulic power plants due to their simplicity in design and fabrication, moderate efficiency, ease of maintenance. The CFHT can be used in low flow and low head conditions with an efficiency of around 90% at rated conditions. However, the efficiency of the CFHT can further be improved by changing its geometric parameters Hence, in the present investigation, 3D unsteady simulations are performed in order to locate the exit blade angle (β2) with the intention is to improve the efficiency of the turbine. In the proposed investigation, the multi-physics FVM solver ANSYS Fluent has been used with the help of the SST k-ω turbulence model to carry out the unsteady simulations. The 3D unsteady simulations are performed by varying the exit blade angle (β2) from 60° to 90° to improve its efficiency when the rotational speed is fixed with the number of blades being 20. From the unsteady simulations, the maximum efficiency of the CFHT is at the exit blade angle (β2) = 80°.


2021 ◽  
Author(s):  
Zicheng Zhong ◽  
Fenglei CHEN ◽  
Song WANG ◽  
Binjie HE

2021 ◽  
Author(s):  
R. S. Lopes ◽  
M. P. Nostrani ◽  
L. A. Carvalho ◽  
A. Dell’Amico ◽  
P. Krus ◽  
...  

Abstract This paper presents the design and modeling process of a flight control actuator using digital hydraulics and a performance analysis that compares the proposed solution and the Servo Hydraulic Actuator (SHA) on a fighter aircraft model. The proposed solution is named Digital Hydraulic Actuator (DHA) and comprises the use of a multi-chamber cylinder controlled by on/off valves and different pressures sources provided by a centralized hydraulic power unit, as proposed in the Fly-by-Wire (FbW) concept. The analyses were carried out using the Aero-Data Model in a Research Environment (ADMIRE), which was developed for flight performance analysis. The actuators were modeled using the software Matlab/Simulink® and Hopsan. They were applied to control the aircraft elevons in a flight mission close to the aircraft limits, to evaluate the actuator’s behavior and energy efficiency. The results show a reduction in energy dissipation up to 22.3 times when comparing the DHA with the SHA, and despite the overshooting and oscillations presented, the aircraft flight stability was not affected.


2021 ◽  
Author(s):  
Carmen-Anca Safta ◽  
Sanda-Carmen Georgescu ◽  
Liliana Dumitrescu

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