Corrective Solutions for the Shaft with Flange Used for Fixing the Blade on a 5 kW Wind Turbine to Withstand Extreme Weather Conditions

2014 ◽  
Vol 1029 ◽  
pp. 118-123
Author(s):  
Rodica Bădărău ◽  
Teodor Miloş ◽  
Ilare Bordeaşu ◽  
Adrian Bej
Keyword(s):  
Mechanical Strength ◽  
Wind Turbine ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Original Solution ◽  
Root Area ◽  
Materials Used ◽  
Improved Design ◽  
The Right ◽  
Technical Solutions

The paper presents a case study on the original solution of a flange shaft as part of the root area of a 5 kW wind turbine blade. There were analyzed the causes that led to the shaft breakage under wind loadings in extreme weather conditions, and consequently technical solutions have been searched in order to improve the shaft design making it more reliable as mechanical strength at extreme wind loadings. The flange shaft is a welded subassembly that keeps the blades attached to the rotor hub. The first part of the paper consists in an analysis referring the loading status, the materials used for blade manufacturing, the identification of critical areas where the breaking was initiated and also the causes for which the materials assumed and specified in the technical design and manufacturing technology failed under loading at wind gusts of about 30 m/sec. Based on this preliminary analysis, the second part of the paper presents the technical solutions which were considered in reference to the materials and the improved design concept aiming to provide the right mechanical strength necessary to withstand specific wind loadings in extreme weather conditions.

scholarly journals Impact of fertilization on production capacity and reaction to fertilization in maize hybrids

2001 ◽  
pp. 42-46
Author(s):  
Péter Jakab
Keyword(s):  
Global Warming ◽  
Production Capacity ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Available P ◽  
Maize Hybrids ◽  
New Varieties ◽  
Main Factors ◽  
The Right

New varieties and fertilization have significantly increased yields of maize in recent decades. It has to be taken into account however that the interactions and the balanced combination of cropping factors (ecological, biological and agrotechnical) are the main factors which determine yields. Weather conditions were rather unfavourable during the last decade. Extreme weather conditions occurred due to global warming; 6 of 10 years were plagued by drought. Consequently yields increased from 10-20% to 30-50%. In view of varieties the situation is advantageous, maybe the supply of hybrids is too high, nevertheless those hybrids need to be selected which are particularly well adjusted to the ecological conditions. Many technologies can be applied which vary according to intensity, but the balanced combination of cropping factors should be secured on the basis of the hybrid’s intensity. Among agrotechnical factors the compensation of nutrients and technological conditions were inadequate. These days farmers only use nitrogenous fertilizers consequently they significantly decrease the easily available P and K content of the soil which in long term leads to the deterioration of the soil’s productivity. The technological background is therefore important, because sufficient yields can only be expected if agrotechnical operations are carried out in the right time and quality. 

scholarly journals AHP method to determine the optimal technological variant for maxillofacial implant fabrication

2018 ◽  
Vol 178 ◽  
pp. 03012
Author(s):  
Luciana Laura Dincă ◽  
Alexandra Banu ◽  
Aurelian Vişan ◽  
Nicolae Ionescu
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Strength ◽  
Technological Process ◽  
Clinical Case ◽  
Metallic Materials ◽  
Optimal Process ◽  
Ahp Method ◽  
Materials Used ◽  
Manufacturing Technologies ◽  
The Right

The paper describes different technologies for manufacturing maxillofacial implant. By using the AHP method the AM, the direct manufacturing technology SLM is the optimal process. Technological variants for obtaining a maxillofacial implant that replaces the right zygomatic bone and a part of maxilla, based on a real clinical case are presented. Starting from the possibility of processing the biocompatible metallic materials used in the oral and maxillofacial technique, it is possible to classify the technological process variants in procedures that use and do not use additive manufacturing technologies. The aim of this paper is to show how important it is to select the optimal technological process in obtaining a maxillofacial implant. It has been analyzed the technological processes of achieving the maxillofacial implant, both those which use the additive manufacturing technologies and those which do not use such technologies, highlighting not only the benefits but also their limits. Based on criteria such as: mechanical strength, porosity, roughness, accuracy, anchorage, time and cost, by using the AHP method, it is possible to choose the optimal technological process for achieving the maxillofacial implant.

scholarly journals Theoretical study on the efficiency of utilization of nanoclay-CFRP composite materials in the root area of wind turbine blades

10.30544/397 ◽  
2018 ◽  
Vol 24 (4) ◽  
Author(s):  
Layth Sayyid Salman Al-Rukaibawi ◽  
Miodrag J Lukic
Keyword(s):  
Composite Materials ◽  
Wind Turbine ◽  
Theoretical Calculations ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Reinforced Polymers ◽  
Root Area ◽  
Carbon Fibre Reinforced Polymers ◽  
Cfrp Composite ◽  
Materials Used

In this study, theoretical calculations were performed to determine the most efficient utilization of nanoclays added as reinforcement for CFRP composite materials used for wind turbine blade manufacture. Four different V39 blade models were created, and numerical simulations by FEA were performed. Glass Fibre Reinforced Polymers (GFRP), whole model made of Carbon Fibre Reinforced Polymers/nanoclay (2%) (CFRPN2), Hybrid Glass and Carbon/nanoclay (2%) (HGCN2) and Hybrid Glass and Carbon/nanoclay (5%) (HGCN5). The targeted part was the joining zone between the root and the blade. The most important finding to emerge from this study is that the modest addition of nanoclay (2%) with carbon fiber reinforced polymer leads to a significant stiffer blade, with a minimal deflection, about 70% lower than GFRP. Furthermore, the HGCN2 model is considered to be safer as it has a lower stress concentration than others (52.84 kN/m2). It can be considered that the probability of failure of the entire root area will be decreased if nanoclay-CFRP hybrid blades are used, yielding higher durability and lower overall costs. These findings contribute to decisions related to materials selection, structural, aerodynamic design and layup schedule choice.

Influence of meteorological factors on potato yield in the conditions of the Right-Bank Forest-steppe

2018 ◽  
Vol 1 (94) ◽  
pp. 55-61
Author(s):  
R.O. Myalkovsky
Keyword(s):  
Meteorological Factors ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Potato Yield ◽  
High Yield ◽  
Forest Steppe ◽  
Potato Tubers ◽  
Middle Aged ◽  
Lower Yield ◽  
The Right

Goal. The purpose of the research was to determine the influence of meteorological factors on potato yield in the conditions of the Right Bank Forest-steppe of Ukraine. Methods.Field, analytical and statistical. Results.It was established that among the mid-range varieties Divo stands out with a yield of 42.3 t/ha, Malin white – 39.8 t/ha, and Legend – 37.1 t/ ha. The most favourable weather and climatic conditions for the production of potato tubers were for the Divo 2011 variety with a yield of 45.9 t/ha and 2013 – 45.1 t/ha. For the Legenda variety 2016, the yield of potato tubers is 40.6 t/ha and 2017 – 43.2 t/ha. Malin White 2013 is 41.4 t/ha and 2017 42.1 t/ha. The average varieties of potatoes showed a slightly lower yield on average over the years of research. However, among the varieties is allocated Nadiyna – 40.3 t/ha, Slovyanka – 37.2 t/ ha and Vera 33.8 t/ha. Among the years, the most high-yielding for the Vera variety was 2016 with a yield of 36.6 t/ha and 2017 year – 37.8 t/ha. Varieties Slovyanka and Nadiyna 2011 and 2012 with yields of 42.6 and 44.3 t/ha and 46.5 and 45.3 t/ha, respectively. Characterizing the yield of potato tubers of medium-late varieties over the years of research, there was a decrease in this indicator compared with medium-early and middle-aged varieties. However, the high yield of the varieties of Dar is allocated – 40.0 t/ha, Alladin – 33.6 t/ha and Oxamit 31.3 t/ha. Among the years, the most favourable ones were: for Oxamit and Alladin – 2011 – 33.5 and 36.5 t/ha, and 2017 – 34.1 and 36.4 t/ha, respectively. Favourable years for harvesting varieties were 2011 and 2012 with yields of 45.7 and 45.8 t/ha. Thus, the highest yield of potato tubers on average over the years of studies of medium-early varieties of 41.2-43.3 t / ha were provided by weather conditions of 2011 and 2017 years, medium-ripe varieties 41.0-41.1 - 2012 and 2011, medium- late 37,6-38,5 t / ha - 2012 and 2011, respectively.

Microcontroller Device for Conductor Identification Using Acoustic Signal

2020 ◽  
Vol 67 (1) ◽  
pp. 28-34
Author(s):  
Aleksandr V. Vinogradov ◽  
Aleksey V. Bukreev
Keyword(s):  
Acoustic Signal ◽  
Acoustic Waves ◽  
Theoretical Calculations ◽  
Poor Quality ◽  
Electrical Circuit ◽  
Research Purpose ◽  
Electrical Wiring ◽  
The Right ◽  
The Cost ◽  
Technical Solutions

When repairing and replacing electrical wiring in enterprises, the main difficulty is the lack or poor quality of documentation, plans for conductors laying. Distinguishing wires (cables) and their cores by the color of the shells or using tags attached to the ends is difficult if the shells have the same color and there are no tags. Devices and technical solutions used to identify wires and cables do not allow recognizing conductors without breaking the electrical circuit, removing insulation, and de-energizing the network. Searching for the right conductor is a time-consuming operation. (Research purpose) The research purpose is developing a new microcontroller device for identifying wires using an acoustic signal. (Materials and methods) Literature sources has been searched for devices for conductors identifying. (Results and discussion) The article proposes a method that involves feeding an acoustic signal to a wire at one point and capturing it at another, in order to recognize the desired wire. The article presents results of comparison of the developed microcontroller device for identifying conductors using an acoustic signal with known devices and methods for conductors recognizing. (Conclusions) The article reveals the shortcomings of existing methods and means of identifying wires and cables. Authors performed a theoretical calculation of the sound pressure in the conductor at a given distance. The article presents the calculation of speed of acoustic waves in conductors with different types of insulation. Authors designed a microcontroller device for identifying conductors using an acoustic signal and tested it. It was determined that the device increases the safety of work, reduces the cost of operating internal wiring and identification time; eliminates the violation of wire insulation, the need to disable electrical receivers. The convergence of theoretical calculations and experimental data was shown.

scholarly journals Rain Erosion Maps for Wind Turbines Based on Geographical Locations: A Case Study in Ireland and Britain

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
K. Pugh ◽  
M. M. Stack
Keyword(s):  
Wind Turbine ◽  
Western Europe ◽  
Meteorological Data ◽  
Turbine Blades ◽  
Weather Conditions ◽  
Annual Rainfall ◽  
Wind Turbine Blades ◽  
Weather Patterns ◽  
The Uk

AbstractErosion rates of wind turbine blades are not constant, and they depend on many external factors including meteorological differences relating to global weather patterns. In order to track the degradation of the turbine blades, it is important to analyse the distribution and change in weather conditions across the country. This case study addresses rainfall in Western Europe using the UK and Ireland data to create a relationship between the erosion rate of wind turbine blades and rainfall for both countries. In order to match the appropriate erosion data to the meteorological data, 2 months of the annual rainfall were chosen, and the differences were analysed. The month of highest rain, January and month of least rain, May were selected for the study. The two variables were then combined with other data including hailstorm events and locations of wind turbine farms to create a general overview of erosion with relation to wind turbine blades.

scholarly journals Precipitation Modeling for Extreme Weather Based on Sparse Hybrid Machine Learning and Markov Chain Random Field in a Multi-Scale Subspace

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1241
Author(s):  
Ming-Hsi Lee ◽  
Yenming J. Chen
Keyword(s):  
Machine Learning ◽  
Markov Chain ◽  
Random Field ◽  
Long Range ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Prediction Algorithm ◽  
Learning Method ◽  
Multi Scale ◽  
Hybrid Machine

This paper proposes to apply a Markov chain random field conditioning method with a hybrid machine learning method to provide long-range precipitation predictions under increasingly extreme weather conditions. Existing precipitation models are limited in time-span, and long-range simulations cannot predict rainfall distribution for a specific year. This paper proposes a hybrid (ensemble) learning method to perform forecasting on a multi-scaled, conditioned functional time series over a sparse l1 space. Therefore, on the basis of this method, a long-range prediction algorithm is developed for applications, such as agriculture or construction works. Our findings show that the conditioning method and multi-scale decomposition in the parse space l1 are proved useful in resisting statistical variation due to increasingly extreme weather conditions. Because the predictions are year-specific, we verify our prediction accuracy for the year we are interested in, but not for other years.

Multi-objective resilience enhancement program in smart grids during extreme weather conditions

2021 ◽  
Vol 129 ◽  
pp. 106824
Author(s):  
Rahman Ashrafi ◽  
Meysam Amirahmadi ◽  
Mohammad Tolou-Askari ◽  
Vahid Ghods
Keyword(s):  
Smart Grids ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Multi Objective
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