scholarly journals Preliminary analysis on an IVHM approach for prognosis of high-pressure filters for hydraulic Power Control Modules of helicopters

2019 ◽  
Vol 304 ◽  
pp. 04017
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli ◽  
Vincenzo Surdo
Keyword(s):  
State Of The Art ◽  
Operating Conditions ◽  
High Fidelity Simulation ◽  
Simulation Environment ◽  
Hydraulic Power ◽  
Hydraulic Equipment ◽  
Rigorous Description ◽  
Rotating Wing ◽  
Control Modules ◽  
Prognostics And Health Monitoring

The process of filtration is critical to ensure long operative life to on-board hydraulic equipment, especially in rotating-wing application where the severe vibratory environment lead to accelerated wear of the mechanical components and hence an increased production of debris. Filtration is obtained by mechanically separating the physical contaminants from the hydraulic fluid by means of filters, which hence tend to clog under prolonged usage. Filter replacement has been so far pursued through scheduled maintenance strategy, which however have proven to be rather cost-ineffective. To transition to a Condition-Based Maintenance, new Prognostics and Health Monitoring frameworks need to be developed. The paper deals with the feasibility analysis of such a system based on a high-fidelity simulation environment, rigorous description of the operating conditions and state-of-the-art algorithms.

scholarly journals Researches for the Modernization of Silage Fodder Distribution Technologies for Cattle

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Ancuta NEDELCU ◽  
Radu CIUPERCA ◽  
Dragos MANEA
Keyword(s):  
Mathematical Model ◽  
State Of The Art ◽  
Hydraulic Power ◽  
Hydraulic Equipment ◽  
Live Stock ◽  
Straw Bale

In order to modernize and turn account the foddering technologies for cattle in live stock farms, a state of the art machine has been achieved aiming to perform several operations within the fodder distributing technology: silage displacement, loading, mincing and mixing, hay and straw bale chopping, fodder automating weighing, mixing homogenizing and distributing the obtained fodder mixture. The paper presents the results of researches aimed to obtain a special hydraulically driven equipment of displacing and loading the ensilage fodder, its characteristics and mathematical model for calculating the required power PE , the hydraulic power PH , in view of properly choosing the hydraulic equipment.

Numerical Investigation of the Solidity Effect on Linear Compressor Cascades

2014 ◽  
Author(s):  
J. Sans ◽  
M. Resmini ◽  
J.-F. Brouckaert ◽  
S. Hiernaux
Keyword(s):  
Numerical Investigation ◽  
State Of The Art ◽  
Leading Edge ◽  
Operating Conditions ◽  
Compressor Cascade ◽  
Minimum Loss ◽  
Low Speed ◽  
High Mach ◽  
The Stability ◽  
The Impact

Solidity in compressors is defined as the ratio of the aerodynamic chord over the peripheral distance between two adjacent blades, the pitch. This parameter is simply the inverse of the pitch-to-chord ratio generally used in turbines. Solidity must be selected at the earliest design phase, i.e. at the level of the meridional design and represents a crucial step in the whole design process. Most of the existing studies on this topic rely on low-speed compressor cascade correlations from Carter or Lieblein. The aim of this work is to update those correlations for state-of-the-art controlled diffusion blades, and extend their application to high Mach number flow regimes more typical of modern compressors. Another objective is also to improve the physical understanding of the solidity effect on compressor performance and stability. A numerical investigation has been performed using the commercial software FINE/Turbo. Two different blade profiles were selected and investigated in the compressible flow regime as an extension to the low-speed data on which the correlations are based. The first cascade uses a standard double circular arc profile, extensively referenced in the literature, while the second configuration uses a state-of-the-art CDB, representative of low pressure compressor stator mid-span profile. Both profiles have been designed with the same inlet and outlet metal angles and the same maximum thickness but the camber and thickness distributions, the stagger angle and the leading edge geometry of the CDB have been optimized. The determination of minimum loss, optimum incidence and deviation is addressed and compared with existing correlations for both configurations and various Mach numbers that have been selected in order to match typical booster stall and choke operating conditions. The emphasis is set on the minimum loss performance at mid-span. The impact of the solidity on the operating range and the stability of the cascade are also studied.

scholarly journals Inner Damping of Water in Conduit of Hydraulic Power Plant

2021 ◽  
Vol 13 (13) ◽  
pp. 7125
Author(s):  
Daniel Himr ◽  
Vladimír Habán ◽  
David Štefan
Keyword(s):  
Power Plant ◽  
Operating Conditions ◽  
Mathematical Apparatus ◽  
Pressure Pulsations ◽  
Hydraulic Power ◽  
Economic Operation ◽  
Compression And Expansion ◽  
Rotor Stator Interaction ◽  
Start Ups

The operation of any hydraulic power plant is accompanied by pressure pulsations that are caused by vortex rope under the runner, rotor–stator interaction and various transitions during changes in operating conditions or start-ups and shut-downs. Water in the conduit undergoes volumetric changes due to these pulsations. Compression and expansion of the water are among the mechanisms by which energy is dissipated in the system, and this corresponds to the second viscosity of water. The better our knowledge of energy dissipation, the greater the possibility of a safer and more economic operation of the hydraulic power plant. This paper focuses on the determination of the second viscosity of water in a conduit. The mathematical apparatus, which is described in the article, is applied to data obtained during commissioning tests in a water storage power plant. The second viscosity is determined using measurements of pressure pulsations in the conduit induced with a ball valve. The result shows a dependency of second viscosity on the frequency of pulsations.

scholarly journals Hybrid Artificial Intelligence Methods for Predicting Air Demand in Dam Bottom Outlet

2021 ◽  
Author(s):  
Aliakbar Narimani ◽  
Moghimi ◽  
Amir Mosavi
Keyword(s):  
Artificial Intelligence ◽  
Economic Value ◽  
Air Entrainment ◽  
Operating Conditions ◽  
Successful Operation ◽  
Volume Rate ◽  
Hydraulic Equipment ◽  
Bottom Outlets ◽  
Hybrid Artificial Intelligence ◽  
Bottom Outlet

In large infrastructures such as dams, which have a relatively high economic value, ensuring the proper operation of the associated hydraulic facilities in different operating conditions is of utmost importance. To ensure the correct and successful operation of the dam's hydraulic equipment and prevent possible damages, including gates and downstream tunnel, to build laboratory models and perform some tests are essential (the advancement of the smart sensors based on artificial intelligence is essential). One of the causes of damage to dam bottom outlets is cavitation in downstream and between the gates, which can impact on dam facilities, and air aeration can be a solution to improve it. In the present study, six dams in different provinces in Iran has been chosen to evaluate the air entrainment in the downstream tunnel experimentally. Three artificial neural networks (ANN) based machine learning (ML) algorithms are used to model and predict the air aeration in the bottom outlet. The proposed models are trained with genetic algorithms (GA), particle swarm optimization (PSO), i.e., ANN-GA, ANN-PSO, and ANFIS-PSO. Two hydrodynamic variables, namely volume rate and opening percentage of the gate, are used as inputs into all bottom outlet models. The results showed that the most optimal model is ANFIS-PSO to predict the dependent value compared with ANN-GA and ANN-PSO. The importance of the volume rate and opening percentage of the dams' gate parameters is more effective for suitable air aeration.

A State-of-the-Art CFD Setup for Axial Compressors: Details and Validation

2020 ◽  
Author(s):  
Lorenzo Cozzi ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Savino Depalo ◽  
Pio Astrua ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Power Plants ◽  
State Of The Art ◽  
Secondary Flows ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Cfd Modelling ◽  
Axial Compressors ◽  
Surge Margin ◽  
Wide Range

Abstract The overall fraction of the power produced by renewable sources in the energy market has significantly increased in recent years. The power output of most of these clean sources is intrinsically variable. At present day and most likely in the upcoming future, due to the lack of inexpensive and reliable large energy storage systems, conventional power plants burning fossil fuels will still be part of the energy horizon. In particular, power generators able to promptly support the grid stability, such as gas turbines, will retain a strategic role. This new energy scenario is pushing gas turbine producers to improve the flexibility of their turbomachines, increasing the need for reliable numerical tools adopted to design and validate the new products also in operating conditions far from the nominal one. Especially when dealing with axial compressors, i.e. machines experiencing intense adverse pressure gradients, complex flow structures and severe secondary flows, CFD modelling of offdesign operation can be a real challenge. In this work, a state-of-the art CFD framework for RANS analysis of axial compressors is presented. The various aspects involved in the whole setup are discussed, including boundary conditions, meshing strategies, mixing planes modelling, tip clearance treatment, shroud leakages and turbulence modelling. Some experiences about the choice of these aspects are provided, derived from a long-date practice on this kind of turbomachines. Numerical results are reported for different full-scale compressors of the Ansaldo Energia fleet, covering a wide range of operating conditions. Furthermore, details about the capability of the setup to predict compressor performance and surge-margin have been added to the work. In particular, the setup surge-margin prediction has been evaluated in an operating condition in which the turbomachine experiences experimental stall. Finally, thanks to several on-field data available at different corrected speeds for operating conditions ranging from minimum to full load, a comprehensive validation of the presented numerical framework is also included in the paper.

scholarly journals Flux-Reducing Tendency of Pd-Based Membranes Employed in Butane Dehydrogenation Processes

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 291 ◽  
Author(s):  
Thijs A. Peters ◽  
Marit Stange ◽  
Rune Bredesen
Keyword(s):  
Competitive Adsorption ◽  
Prolonged Exposure ◽  
Hydrogen Permeation ◽  
State Of The Art ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Hydrogen Flux ◽  
Membrane Performance ◽  
Wide Range

We report on the effect of butane and butylene on hydrogen permeation through thin state-of-the-art Pd–Ag alloy membranes. A wide range of operating conditions, such as temperature (200–450 °C) and H2/butylene (or butane) ratio (0.5–3), on the flux-reducing tendency were investigated. In addition, the behavior of membrane performance during prolonged exposure to butylene was evaluated. In the presence of butane, the flux-reducing tendency was found to be limited up to the maximum temperature investigated, 450 °C. Compared to butane, the flux-reducing tendency in the presence of butylene was severe. At 400 °C and 20% butylene, the flux decreases by ~85% after 3 h of exposure but depends on temperature and the H2/butylene ratio. In terms of operating temperature, an optimal performance was found at 250–300 °C with respect to obtaining the highest absolute hydrogen flux in the presence of butylene. At lower temperatures, the competitive adsorption of butylene over hydrogen accounts for a large initial flux penalty.

scholarly journals Integrated Simulation Environment for Unmanned Autonomous Systems—Towards a Conceptual Framework

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
M. G. Perhinschi ◽  
M. R. Napolitano ◽  
S. Tamayo
Keyword(s):  
Conceptual Framework ◽  
State Of The Art ◽  
Autonomous Systems ◽  
Simulation Environment ◽  
Integrated Simulation ◽  
Systems Perspective ◽  
Future Developments ◽  
Current State ◽  
And Performance ◽  
Testing And Evaluation

The paper initiates a comprehensive conceptual framework for an integrated simulation environment for unmanned autonomous systems (UAS) that is capable of supporting the design, analysis, testing, and evaluation from a “system of systems” perspective. The paper also investigates the current state of the art of modeling and performance assessment of UAS and their components and identifies directions for future developments. All the components of a comprehensive simulation environment focused on the testing and evaluation of UAS are identified and defined through detailed analysis of current and future required capabilities and performance. The generality and completeness of the simulation environment is ensured by including all operational domains, types of agents, external systems, missions, and interactions between components. The conceptual framework for the simulation environment is formulated with flexibility, modularity, generality, and portability as key objectives. The development of the conceptual framework for the UAS simulation reveals important aspects related to the mechanisms and interactions that determine specific UAS characteristics including complexity, adaptability, synergy, and high impact of artificial and human intelligence on system performance and effectiveness.

Study of Light Weight Turbine Transmission Systems

1976 ◽  
Author(s):  
D. J. Fessett
Keyword(s):  
Gas Turbines ◽  
State Of The Art ◽  
Chain Drive ◽  
Tape Drive ◽  
Hydraulic Power ◽  
Transmission Systems ◽  
Determining Factors ◽  
Technical Risks ◽  
The Right ◽  
Marine Vessels

Several transmission systems that are applicable to advanced marine vessels were investigated to determine if drives other than right-angle gearboxes would be practical in transmitting 50,000 (37.3 NW) hp from dual gas turbines downward through a vertical distance of 20 (6.10 m) ft to a propeller drive shaft. These systems included: hydraulic power, chain drive, steel tape drive, and a slider crank drive. Results of this survey indicated the right-angle bevel gear drive was the optimum system considering our present state-of-the-art. Further investigation was performed to optimize turbine and gearbox arrangement using weight, reliability, efficiency, serviceability, technical risks, and relative cost as the determining factors.

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