Numerical analysis of flow around a fan blade of a CFM56-3

This work was performed in cooperation with TAP maintenance and engineering, speci cally the engine shop’s engineering team. The main goal is to analyze the ow around a fan blade of a CFM56-3 engine. The ow analysis around a blade intends essentially to learn the relations between the chord variation and the consequent changes in the ow properties, particularly two, mach number and total pressure, and doing after a results validation process using the TAP-ME test bench readings as a reference. The Navier-Stokes equations for compressible and adiabatic ow are the governing equations of this problem. However, it was necessary to adapt these equatios for a reference moving frame, so as to be adjusted to a rotating fan problem. The averaged Navier-Stokes equations are resolved along with the K-W SST turbulence model. The control volume of this problem was divided in three domains (inlet, blade and outlet) and three different blade chords were created (small, medium and Large). After control volume construction the grids were created using the software Turbomesh, two domains use structured grids and the third uses an unstructured grid and the suitable boundary conditions are applied. It was chosen the commercial software ANSYS CFX 15 as the most suitable for this study, then six simulations are performed, three of those simulations were executed in take-off regime and the other three in maximum continuous. After the completion of the simulations and the results obtained, the most relevant for this investigation are selected. The numerical solutions were analyzed in detail for the convergence and accuracy in order to guarantee the quality of those solutions. The results are then presented for all simulations in several views and for two essential properties, mach number and total pressure. Then a comparative analysis is performed for two parameters in order to learn the differences between variations in blade chord and different regimes. Subsequently, there is an analysis to validate the numerical model, in which the numerical solutions are compared with experimental data taken from one of the databases of the TAP-ME test bench. The comparison is made for some parameters that can be measured on the test bench and is then completed and the validity of the model is proofed since there is good agreement between values. Finally, are present the main ndings of this research and are also indicated some proposals for future works as well as work that is currently under development, which aims to apply the results of this work.Este trabalho foi realizado em cooperação com a equipa de manutenção de motores da TAP Manutenção e Engenharia e surgiu com o intuito de analisar o escoamento em torno das pás da fan do motor CFM56-3. A análise do escoamento em torno da fan pretende essencialmente entender as relações entre a variação da corda e a alteração das propriedades, em particular duas propriedades essenciais, Mach number e Pressão total, procedendo posteriormente á validação dos resultados através das leituras dos testes efetuados no banco de ensaio da TAP-ME. As equações de governo do problema são as equações de Navier-Stokes para escoamento compress ível e adiabático. Foi então necessário adaptar as equações para um um moving reference frame de forma a serem ajustadas ao problema de uma pá em rotação. As equações de Navier Stokes em termos dos valores médios (RANS) são resolvidas, juntamente com o modelo de turbul ência k-w sst. O volume de controlo do problema foi dividido em três domínios (inlet, blade, outlet), e foram criadas três pás com cordas diferentes (pequena, média, grande). Após a construção do volume de controlo foram compostas no software Turbomesh malhas estruturadas em 2 domínios e não estruturada no terceiro e são então aplicadas as condições de fronteira adequadas. Procedeu-se á escolha do software comercial ANSYS CFX 15 como sendo o mais adequado á realização deste estudo, e são então realizadas 6 simulações, destas, três simula ções foram executadas em regime de Take-off e as restantes três em Maximum continuous. Após a realização das simulações e da obtenção de todos os resultados, são selecionados os mais relevantes para a investigação. As soluções numéricas foram então detalhadamente analisadas para a convergência e precisão para garantir a qualidade das mesmas. Os resultados são apresentados para todas as simulações em várias vistas e para duas propriedades essências, Mach number e Pressão total. É então efetuada uma análise comparativa destes dois parâmetros para permitir uma melhor compreensão das diferenças entre as diferentes cordas e diferentes regimes. Posteriormente existe uma análise para a validação do modelo numérico, em que as soluções numéricas são comparadas com os dados experimentais retirados de uma das bases de dados do banco de ensaio da TAP-ME. A comparação é efetuada para alguns parâmetros que podem ser medidos no banco de ensaio e é então concluída a validade do modelo uma vez que existe boa concordância entre valores. Para nalizar são apresentadas as principais conclusões desta investigação e são também indicadas algumas propostas para trabalhos futuros assim como um trabalho que esta atualmente em desenvolvimento, que pretende aplicar os resultados deste trabalho

Fatigue Behavior of Metallic Components Obtained by Topology Optimization for Additive Manufacturing

The main goal of the present research is to propose an integrated methodology to address the fatigue performance of topology optimized components, produced by additive manufacturing. The main steps of the component design will be presented, specially the methods and parameters applied to the topology optimization and the post-smoothing process. The SIMP method was applied in order to obtain a lighter component and a suitable stiffness for the desired application. In addition, since residual stresses are intrinsic to every metallic additive manufacturing process, the influence of those stresses will be also analyzed. The Laser Powder Bed Fusion was numerically simulated aiming at evaluating the residual stresses the workpiece during the manufacturing process and to investigate how they could influence the fatigue behavior of the optimized component. The effect of the built orientation of the workpiece on the residual stresses at some selected potential critical points are evaluated. The final design solution presented a stiffness/volume ratio nearly 6 times higher when compared to the initial geometry. By choosing the built orientation, it is possible impact favorably in the fatigue life of the component

Impact of composition and morphology on the optical properties of Si-NC/P3HT thin films processed from solution

Blends of Si nanocrystals (Si-NCs) and organic semiconductors are promising materials for new optical and electronic devices processed from solutions. Here, we study how the optical properties of composite films containing Si-NCs and the organic semiconductor poly(3-hexylthiophene) (P3HT) are influenced by the composition and morphology resulting from different solution-processing parameters and different solvents used dichlorobenzene vs. chloroform). The optical spectra of the hybrid films are described using a simple phenomenological model, with which we can discern the contribution of each material in the films to the optical properties. From this analysis, we obtain quantitative information about the composition and morphology of the hybrid nanostructured films, which otherwise would be obtained from more demanding microscopy and spectroscopy techniques. For the case of the Si-NC/P3HT blend, we find that in films deposited from dichlorobenzene solutions the Si-NCs contribute sizably to light absorption.This work was funded by FCT/I3N via the HybridSolar project, by the DFG via Teilprojekt B2 and by the European Union and the Ministry of Innovation, Science and Research of the German State of North Rhine-Westphalia in the framework of an Objective 2 Programme (European Regional Development Fund, ERDF). Funding is also acknowledged from the Portuguese Foundation for Science and Technology (FCT) through the Projects Nos. PTDC/FIS/112885/2009 and PEst-C/CTM/LA0025/2011 and via the Strategic Project LA 25:2011-2012

Kaolin Application Modulates Grapevine Photochemistry and Defence Responses in Distinct Mediterranean-Type Climate Vineyards

At a local scale, kaolin particle-film technology is considered a short-term adaptation strategy to mitigate the adverse effects of global warming on viticulture. This study aims to evaluate kaolin application effects on photochemistry and related defence responses of Touriga Franca (TF) and Touriga Nacional (TN) grapevines planted at two Portuguese winegrowing regions (Douro and Alentejo) over two summer seasons (2017 and 2018). For this purpose, chlorophyll a fluorescence transient analysis, leaf temperature, foliar metabolites, and the expression of genes related to heat stress (VvHSP70) and stress tolerance (VvWRKY18) were analysed. Kaolin application had an inhibitory effect on VvHSP70 expression, reinforcing its protective role against heat stress. However, VvWRKY18 gene expression and foliar metabolites accumulation revealed lower gene expression in TN-treated leaves and higher in TF at Alentejo, while lipid peroxidation levels decreased in both treated varieties and regions. The positive kaolin effect on the performance index parameter (PIABS) increased at ripening, mainly in TN, suggesting that stress responses can differ among varieties, depending on the initial acclimation to kaolin treatment. Moreover, changes on chlorophyll fluorescence transient analysis were more pronounced at the Douro site in 2017, indicating higher stress severity and impacts at this site, which boosted kaolin efficiency in alleviating summer stress. Under applied contexts, kaolin application can be considered a promising practice to minimise summer stress impacts in grapevines grown in Mediterranean-like climate regions

The CgHaa1-dependent pathway mediates Candida glabrata response and tolerance to acetic acid thereby enhancing colonization of vaginal epithelium

To successfully colonize the vaginal tract Candida glabrata has to cope with various stresses including the presence of acetic acid at a low pH that is produced by the bacteria that co-colonize this niche. The genes/pathways involved in C. glabrata tolerance and response to acetic acid are largely unknown, although these are a highly interesting set of novel targets to control vaginal infections caused by this yeast. Saccharomyces cerevisae response and tolerance to acetic acid was found to be largely mediated by the ScHaa1 transcription factor [1,2,3]. In this work the involvement of CgHaa1 in C. glabrata tolerance and response to acetic acid is demonstrated. Elimination of CgHAA1 gene from C. glabrata genome dramatically increased susceptibility of this pathogenic yeast to acetic acid (30 mM at pH 4.0). Around 140 genes were found to be up-regulated, directly or indirectly, by CgHaa1 in response to acetic acid stress, based on results of a transcriptomic analysis. Functional clustering of the genes activated by CgHaa1 under acetic acid stress shows an enrichment of those involved in carbohydrate metabolism, transport, cell wall maintenance, regulation of internal pH and nucleic acid processing. At least five of the CgHaa1-regulated genes were found to increase C. glabrata tolerance to acetic acid including CgGAD1, encoding a glutamate decarboxylase; CgTPO2/3, encoding a drug efflux pump of the Major Facilitator Superfamily; CgYPS1, encoding a cell wall aspartyl protease; and CAGL0H04851 and CAGL0E03740, encoding two uncharacterized ORFs. Altogether our results are consistent with the concept that the CgHaa1- signalling pathway increases C. glabrata tolerance to acetic acid by reducing the internal accumulation of the acid and by up-regulating the activity of the plasma membrane proton pump H+-ATPase CgPma1, two essential features for a robust weak acid response. The role exerted by CgHaa1 in the ability of C. glabrata to colonize reconstituted vaginal human epithelium (RVHE) in the presence of acetic acid (30 mM at pH 4.0) was also investigated in this work. In the absence of acetic acid wild-type and DCgHaa1 mutant cells were able to colonize RVHE at a similar rate, however, in the presence of acetic acid colonization of the vaginal tissue was markedly reduced in the mutant background. The reduced colonizing capacity of DCgHaa1 mutant cells was correlated with a reduced expression of the adhesin-encoding genes EPA6, EPA7 and EPA1 and with a lower adhesiveness to the extracellular matrix proteins fibronectin and vitronectin

Kaolin foliar application has a stimulatory effect on phenylpropanoid and flavonoid pathways in grape berries

The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fpls.2016. 01150Drought, elevated air temperature, and high evaporative demand are increasingly frequent during summer in grape growing areas like the Mediterranean basin, limiting grapevine productivity and berry quality. The foliar exogenous application of kaolin, a radiation-reflecting inert mineral, has proven effective in mitigating the negative impacts of these abiotic stresses in grapevine and other fruit crops, however, little is known about its influence on the composition of the grape berry and on key molecular mechanisms and metabolic pathways notably important for grape berry quality parameters. Here, we performed a thorough molecular and biochemical analysis to assess how foliar application of kaolin influences major secondary metabolism pathways associated with berry quality-traits, leading to biosynthesis of phenolics and anthocyanins, with a focus on the phenylpropanoid, flavonoid (both flavonol- and anthocyanin-biosynthetic) and stilbenoid pathways. In grape berries from different ripening stages, targeted transcriptional analysis by qPCR revealed that several genes involved in these pathways—VvPAL1, VvC4H1, VvSTSs, VvCHS1, VvFLS1, VvDFR, and VvUFGT—were more expressed in response to the foliar kaolin treatment, particularly in the latter maturation phases. In agreement, enzymatic activities of phenylalanine ammonia lyase (PAL), flavonol synthase (FLS), and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) were about two-fold higher in mature or fully mature berries from kaolin-treated plants, suggesting regulation also at a transcriptional level. The expression of the glutathione S-transferase VvGST4, and of the tonoplast anthocyanin transporters VvMATE1 and VvABCC1 were also all significantly increased at véraison and in mature berries, thus, when anthocyanins start to accumulate in the vacuole, in agreement with previously observed higher total concentrations of phenolics and anthocyanins in berries from kaolin-treated plaThe work was supported by European Union Funds (FEDER/COMPETE-Operational Competitiveness Programme —INNOVINE—ref. 311775, Enoexcel—Norte—07-0124FEDER-000032 and INTERACT - NORTE-01-0145-FEDER000017 - Linha VitalityWine - ON 0013), and by Portuguese national funds (FCT-Portuguese Foundation for Science and Technology) under the project FCOMP-01-0124FEDER-022692. AC was supported by Enoexcel—Norte— 07-0124-FEDER-000032 and INTERACT - NORTE-010145-FEDER-000017.This work also benefited from the networking activities within the European funded COST ACTION FA1106 “QualityFruit.”info:eu-repo/semantics/publishedVersio

The CgHaa1-regulon mediates response and tolerance to acetic acid stress in the human pathogen Candida glabrata

To thrive in the acidic vaginal tract C. glabrata has to cope with high concentrations of acetic acid. The mechanisms underlying C. glabrata tolerance to acetic acid at low pH remain largely uncharacterized. In this work it is demonstrated the essential role of the CgHaa1 transcription factor (encoded by ORF CAGL0L09339g) in the response and tolerance of C. glabrata to acetic acid. Transcriptomic analysis showed that CgHaa1 regulates, directly or indirectly, the expression of about 75% of the genes activated under acetic acid stress. CgHaa1-activated targets are involved in multiple physiological functions including membrane transport, metabolism of carbohydrates and amino acids, regulation of the activity of the plasma membrane H+-ATPase and adhesion. Under acetic acid stress CgHaa1 increased the activity and the expression of the CgPma1 proton pump and contributed to increased colonization of vaginal epithelial cells by C. glabrata. CgHAA1, CgTPO3 and CgHSP30, two identified CgHaa1-activated targets, are herein demonstrated to be determinants of C. glabrata tolerance to acetic acid. The protective effect of CgTpo3 and of CgHaa1 was linked to a role of these proteins in reducing the accumulation of acetic acid inside C. glabrata cells. In response to acetic acid stress, marked differences were found in the regulons controlled by CgHaa1 and by its S. cerevisiae ScHaa1 ortholog, demonstrating a clear divergent evolution of the two regulatory networks. The results gathered in this study significantly advance the understanding of the molecular mechanisms underlying the success of C. glabrata as a vaginal colonizer.Cristoph Schueller (University of Natural Resources and Life Sciences, Austria) and Ken Haynes (University of Exeter, UK) are acknowledged for sharing strains. Funding received by the Institute for Bioengineering and Biosciences from the Portuguese Foundation for Science and Technology (FCT) (UID/BIO/04565/2013) and from Programa Operacional Regional de Lisboa 2020 (project no. 007317)is acknowledged. FCT is also acknowledged for funding the Centre of Biological Engineering through contracts FCOMP-01-0124-FEDER020243 and PTDC/EBB-EBI/120495/2010. Science Foundation Ireland and the Wellcome Trust are acknowledged for funding G.B

Optimising grapevine summer stress responses and hormonal balance by applying kaolin in two Portuguese Demarcated Regions

In Mediterranean-like climate areas, field-grown grapevines are typically exposed to severe environmental conditions during the summer season, which can negatively impact the sustainability of viticulture. Despite the short-term mitigation strategies available nowadays to cope with climate change, little is known regarding their effectiveness in different demarcated winegrowing regions with differing climate features. Hence, we applied a kaolin suspension (5 %) to Touriga-Franca (TF) and Touriga-Nacional (TN) grapevine varieties located in two Portuguese demarcated regions (Alentejo and Douro) with different mesoclimates to study its effect on the physiological performance, hormonal balance and ABA-related grapevine leaf gene expression during the 2017 and 2018 growing seasons. Data show that 2017 was warmer than 2018 due to the occurrence of two heatwaves in both locations, highlighting the protective effect of kaolin application under severe environmental conditions. In the first study year, at midday, kaolin enhanced water use efficiency (23 % in Douro and 13 % in Alentejo), carbon assimilation rates (PN; 72 % in Douro and 25 % in Alentejo), and the soluble sugar content of grapevine leaves, while decreasing the accumulation of plant growth regulators (ABA, IAA, and SA) during the ripening stage. The results show an up-regulation of ABA biosynthesis-related genes (VvNCED) in TF treated vines from the Douro vineyard mainly in 2017, suggesting an increased stress response under severe summer conditions. Additionally, kaolin triggered the expression of ABA-responsive genes (VvHVA22a and VvSnRK2.6) mainly in TF, indicating different varietal responses to kaolin application under fluctuating periods of summer stress