scholarly journals Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model

2021 ◽  
Vol 13 (16) ◽  
pp. 9114
Author(s):  
Alejandro Ballesteros-Coll ◽  
Koldo Portal-Porras ◽  
Unai Fernandez-Gamiz ◽  
Ekaitz Zulueta ◽  
Jose Manuel Lopez-Guede

Flow control device modeling is an engaging research field for wind turbine optimization, since in recent years wind turbines have grown in proportions and weight. The purpose of the present work was to study the performance and effects generated by a rotating microtab (MT) implemented on the trailing edge of a DU91W250 airfoil through the novel cell-set (CS) model for the first time via CFD techniques. The CS method is based on the reutilization of an already calculated mesh for the addition of new geometries on it. To accomplish that objective, the required region is split from the main domain, and new boundaries are assigned to the mentioned construction. Three different MT lengths were considered: h = 1%, 1.5% and 2% of the airfoil chord length, as well as seven MT orientations (β): from 0° to −90° regarding the horizontal axis, for five angles of attack: 0°, 2°, 4°, 6° and 9°. The numerical results showed that the increases of the β rotating angle and the MT length (h) led to higher aerodynamic performance of the airfoil, CL/CD = 164.10 being the maximum ratio obtained. All the performance curves showed an asymptotic trend as the β angle reduced. Qualitatively, the model behaved as expected, proving the relationship between velocity and pressure. Taking into consideration resulting data, the cell-set method is appropriate for computational testing of trailing edge rotating microtab geometry.

2020 ◽  
pp. 137-179
Author(s):  
Iain Crawford

Building on the case made in chapter 3, chapter 4 tunes to consider Martin Chuzzlewit and examines the ways in which the novel addresses the relationship between literacy, print media, and the experience of modern urbanism. Together eith its predecessor, the chapter argues that for Dickens America was far more than what has been generally perceived as an increasingly negative experience that chastened his understanding of the press and of mass culture. Rather, and notwithstanding all his complaints about Americans, tobacco, and spit, the encounter with America in fact provided him with a new sense, at once disturbing and alluring, of the potential power of a cheap mass-market press led by entrepreneurial editors operating in a print environment unconstrained by state controls. Moreover, in writing about America, and above all in writing about its newspapers in both American Notes and Martin Chuzzlewit, Dickens for the first time discovered a methodology for fusing fiction and the press in ways that would be foundational his most significant contribution to Victorian journalism, Household Words and its successor, All the Year Round.


2017 ◽  
Vol 29 (6) ◽  
pp. 1038-1049 ◽  
Author(s):  
Daochun Li ◽  
Qichen Liu ◽  
Yining Wu ◽  
Jinwu Xiang

The split drag rudder is an important yawing control device for the tailless flying-wing aircraft. In this article, a new morphing drag rudder is proposed based on the chordwise continuous variable camber technology. The designs of the structure and actuation system are first presented. A comparative study on the aerodynamics of the morphing and traditional drag rudders is performed numerically. The results show that the morphing drag rudder experiences a larger aerodynamic drag than the traditional one at small angles of attack. The analysis on the structural deformation and the required actuating moment at zero angle of attack are performed. The results show that the deformation due to the aerodynamic load increases more and more slowly with the angle of deflection. Besides, the relationship between the required actuating moment and the trailing edge deformation is linear, which indicates the applicability of using morphing drag rudder for yawing control.


Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6723
Author(s):  
Alejandro Ballesteros-Coll ◽  
Unai Fernandez-Gamiz ◽  
Iñigo Aramendia ◽  
Ekaitz Zulueta ◽  
José Antonio Ramos-Hernanz

Microtabs (MTs) are a regularly used flow control device in terms of wind turbine optimization. The present study introduces the application of the novel cell-set model for an MT implementation on a DU91W(2)250 airfoil. The cell-set model is based on the reusability of a mesh to add new geometries on the domain; the matching geometry is located where the user requires, and a set of cells is constructed around the mentioned geometry. Subsequently, wall boundaries are assigned to the generated region. Computational simulations were carried out for fully mesh and cell-set models: MT lengths were set at 1.0%, 1.5% and 2.0% of the airfoil chord length (c) and the MTs were placed at 93% and 95% of c from the leading edge of the airfoil. Resulting data showed that the MT behavior was similar for both models with regard to aerodynamic performance curve representations. A global relative error of 3.784% was obtained for the cell-set model and a maximum relative error of 7.332% was determined. Qualitatively, both models generated significantly similar flow stream velocity wakes on the trailing edge area of the airfoil.


2021 ◽  
pp. 101-115
Author(s):  
И.В. МАМИЕВА

В статье впервые в диахронном аспекте исследуется динамика связей осетинской литературы с эпической традицией, степень и характер востребованности ее на отдельных этапах развития художественного сознания. Цель работы – изучение специфики отражения «темы нартов», синтеза конвенционального и индивидуально-авторского начал в произведениях различных эпох, стилей и жанровых форм. Применены описательно-функциональный и мифопоэтический методы с использованием герменевтических приемов анализа текстов, вызвавших оживленную дискуссию. Отрефлексирован опыт пересоздания фольклорных мотивов и образов в творчестве К.Л. Хетагурова («Всати», «В пастухах», «На кладбище»). Особый акцент сделан на эпических константах национального мира в литературном процессе второй половины ХХ в. Обрисованы новые подходы писателей к осмыслению феноменов, составляющих значимый пласт в культурном пространстве осетин (фандыр, свирель Ацамаза, чаша Уацамонга, Кадаг-Сказание и пр.). Рассмотрен мифоэпический слой в структуре современной повести (К. Дзесов, Н. Джусойты, Г. Агнаев). Выделены характерные черты, такие как инкорпорирование мифологических реминисценций в художественную ткань произведений; двуприродность персонажа, вызванная имплицитными уподоблениями (сюжетно-мотивный и субъектный уровни); постановка и решение в «нартовском духе» проблемы праведного и греховного пути, антиномии «жизнь после смерти» – «смерть при жизни». Качественно иной уровень освоения темы (последняя треть ХХ – начало XXI в.), позиционируемый в статье как вершина синтеза фольклорно-мифологических и литературных истоков, соотнесен с зарождением в прозе новой жанровой разновидности – романа-мифа. Сделан вывод о том, что, несмотря на неоднородность поэтапного взаимодействия двух эстетических систем, Нартиада – непрерывный фундаментальный источник развития национальной словесности. In the article, for the first time in the diachronic aspect, the dynamics of the relationship of Ossetian literature with the mythoepic tradition, the degree and nature of its relevance at certain stages of the development of artistic consciousness. The purpose of the work is to study the specifics of the reproduction of the "theme of the Narts" by Ossetian writers, the synthesis of the mythical-epic and individual-author's principles in works of different eras, styles and genre forms. Descriptive-functional and mythopoetic methods were applied with the use of hermeneutic techniques in the analysis of texts on which there were lively discussions. The experience of recreating epic motifs and images in the work of the classic of Ossetian literature K.L. Khetagurov (poems "Vsati", "In the shepherds", "At the cemetery") is reflected. Special emphasis is placed on the reflection of the epic constants of the national world in the literary process of the second half of the twentieth century. New approaches of writers to the understanding of the phenomen that make up a significant layer in the cultural space of the Ossetians (fandyr, Atsamaz's flute, Uatsamonga bowl, Kadag- Saga, etc.) are analyzed. The mythoepic layer in the structure of the modern story is outlined (K. Dzesov, N. Dzhusoyty, G. Agnaev). The characteristic features are highlighted, such as: incorporation of mythological reminiscences into the artistic fabric of works; the character's two-naturedness caused by implicit comparisons (plot-motive and subjective levels); posing and solving in the “Nart spirit” the problem of the righteous and sinful path, the antinomy “life after death” – “death during life”. The next stage in the development of the theme of the Narts (the last third of the XX – the beginning of the XXI century), positioned in the article as the pinnacle of the synthesis of mythical-epic and literary principles, is correlated with the emergence in Ossetian literature of a new genre variety – the novel-myth. It is concluded that the Nartiada is a continuous fundamental source of the development of Ossetian literary literature, despite the heterogeneity of causal relations between the two aesthetic systems in different time periods.


Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 494 ◽  
Author(s):  
Qing Pan ◽  
Jing Wang ◽  
Yulong Gao ◽  
Hongyu Cui ◽  
Changjun Liu ◽  
...  

Since 2015, severe hydropericardium-hepatitis syndrome (HHS), caused by a highly pathogenic fowl adenovirus 4 (FAdV-4), emerged in China. In our previous study, the FAdV-4 has been identified as a novel genotype with a unique 1966-bp nucleotide deletion (1966Del) between open reading frame 42 and 43. In this study, the natural 1966Del was frequently identified among 17 clinical isolates and other reported Chinese clinical strains. To investigate the relationship between 1966Del and the increased virulence of the novel FAdV-4, a CRISPR/Cas9 operating platform for FAdV-4 was developed for the first time in this study. Based on this platform, a Re1966 strain was rescued, inserted the relative 1966Del sequence of a nonpathogenic strain KR5. In the pathogenicity study, the Re1966 strain retained high virulence for specific-pathogen-free chickens, similar to the parental wild-type HLJFAd15, although the survival time of chickens infected with Re1966 was much longer. Therefore, the natural 1966Del was identified as a non-essential site for the increased virulence of the emerged novel FAdV-4. Although further research on the virulence-determining region or point within the genome of the novel FAdV-4 is needed, the CRISPR/Cas9 operating platform for the novel FAdV-4 was developed and successfully applied to edit the genomic DNA for the first time, and it provides a novel powerful tool for both basic virology studies and vaccine vector development of FAdVs.


2020 ◽  
Vol 3 (2) ◽  
pp. 17-31
Author(s):  
Helmita Helmita ◽  
Elsa Mayora Putri

The problem in this thesis is Devotion and commitment in a contradictory conditions in the relationship between Noah and Allie who have differences in social status. Until their relationship was opposed by Allie's mother, even so Allie remained devotion to choose Noahh. Devotion and commitment to the contradictory conditions between Noah and Allie also occur when they are old. Noah remained loyal to Allie when she suffered from Alzheimer's disease. The object of this study was The Notebook novel by Nicholas Sparks. This research uses Sigmund Freud's theory of personality psychology. The results of this study are the figures Noah and Alli have personality aspects that refer to Sigmund Freud's theory of id, ego, superego. The writer uses descriptive analysis method and qualitative method. The author carries out a systematic procedure with an understanding of the novel, figures Noah and Allie, and also structural theory. This research aims : (1) to analyze the importance of loyalty and commitment in contradictory conditions. (2) to describe the loyalty and commitment contained in the Novel The notebook. (3) to explain the loyalty and commitment shown by Noah and Allie after marriage. Based on the results of this analysis it can be concluded that the problem faced by the main character is his deep love and loyalty to his wife, Noah did everything for Allie, including writing to him for two years even though his letter was never responded by Allie. But when they met for the first time after being separated for quite a long time their love for each other was still there. Until they married and aged together and Allie contracted Alzheimer's disease, but Noah remained faithful with her.


Author(s):  
Susanne-Marie Kirsch ◽  
Felix Welsch ◽  
Domenico Bevilacqua ◽  
David Naso ◽  
Stefan Seelecke ◽  
...  

Abstract Shape memory alloys (SMA) are used as an attractive technology in the field of actuators and sensors due to their versatile geometry, lightweight, high energy density, and low cost. The thermal activation principle, however, makes SMA application generally suitable for low-frequency (few Hz) regimes. In this work, a novel SMA-based antagonistic actuation system and its manufacturing process are presented for the first time. The main feature of the novel actuator concept is the possibility of being operated at frequencies up to at least 20 Hz. It spares the usual complex and time-consuming manufacturing of such a system. First parameter studies of a rotary actuation system are performed. The relationship existing between the pulse energy, frequency, and the resulting rotation angle is investigated through an extensive experimental campaign.


2019 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Xuezhong He

The novel tubular carbon membranes produced from natural materials are, for the first time, reported. The novelty of this idea is to use natural rattans as precursors for making carbon membranes to address the challenges of cellulose polymers. The rattan precursors were carbonized to present evenly distributed channels inside the tubular carbon membranes. Each channel has an inner diameter of 2 × 10−4 m with a dense-selective inner layer and a porous outer layer. Future work on selection of suitable rattans, proper pre-treatment, carbon structure tailoring can be conducted to open a new research field of carbon membranes/materials.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3078
Author(s):  
Yingying Li ◽  
Jingfeng Huang

Leaf pigment content retrieval is an essential research field in remote sensing. However, retrieval studies on anthocyanins are quite rare compared to those on chlorophylls and carotenoids. Given the critical physiological significance of anthocyanins, this situation should be improved. In this study, using the reflectance, partial least squares regression (PLSR) and Gaussian process regression (GPR) were sought to retrieve the leaf anthocyanin content. To our knowledge, this is the first time that PLSR and GPR have been employed in such studies. The results showed that, based on the logarithmic transformation of the reflectance (log(1/R)) with 564 and 705 nm, the GPR model performed the best (R2/RMSE (nmol/cm2): 0.93/2.18 in the calibration, and 0.93/2.20 in the validation) of all the investigated methods. The PLSR model involved four wavelengths and achieved relatively low accuracy (R2/RMSE (nmol/cm2): 0.87/2.88 in calibration, and 0.88/2.89 in validation). GPR apparently outperformed PLSR. The reason was likely that the non-linear property made GPR more effective than the linear PLSR in characterizing the relationship for the absorbance vs. content of anthocyanins. For GPR, selected wavelengths around the green peak and red edge region (one from each) were promising to build simple and accurate two-wavelength models with R2 > 0.90.


2011 ◽  
Vol 10 (3) ◽  
pp. 139-143 ◽  
Author(s):  
Gazi Islam ◽  
Sarah E. S. Zilenovsky

This note examines the relationship between affirmative action (AA) program perceptions and women’s self-ascribed capacity and desire to become leaders. We propose that women who believe that their organization implements a program of preferential selection toward women will experience negative psychological effects leading to lowered self-expectations for leadership, but that this effect will be moderated by their justice perceptions of AA programs. We test this proposition empirically for the first time with a Latin American female sample. Among Brazilian women managers, desire but not self-ascribed capacity to lead was reduced when they believed an AA policy was in place. Both desire’s and capacity’s relationships with belief in an AA policy were moderated by justice perceptions.


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