bluuebunny/crossref_metadata_2025 huggingface dataset:
Slovácko Verbuňk as a Tradition and Performance
Authors:   Ústav etnologie Filozofické fakulty Univerzity Karlovy, Jagošová Anna
Published: July 2023

The Slovácko verbuňk is a solo male dance of jumping nature. Originally, it was part of military recruiting and was danced by soldiers or, much more often, by the recruiters. Verbuňk had many functions. Some of them, for example the psychological and the symbolic and social ones, have already disappeared, some others, such as the identification, erotic, and competitive ones have survived to date. It is due to the competitive feature of the dance that a “dance race” has been organized at the International Folklore Festival in Strážnice since its foundation; the Festival has given rise to the Contest for the Best Dancer of the Slovácko Verbuňk. This has significantly changed the form of the Slovácko verbuňk - for example, the Contest has supressed the improvisation, but increased the awareness of the dance and attracted many dancers who want to learn it. The performance of the Slovácko verbuňk by child dancers is a phenomenon of the last twenty years. This fact has its supporters and opponents among Slovácko verbuňk dancers and leaders of folk ensembles.
Whitsunday Procession of Královničky in Svatobořice-Mistřín. The Current Condition of the Customary Tradition
Authors:   Ústav evropské etnologie Filozofické fakulty Masarykovy univerzity, Drastil Petr
Published: July 2023

Applying the micro-historical approach, the presented study maps fifteen years of the renewed tradition of Královničky [Little Queens] in the Slovácko village of Svatobořice-Mistřín (District of Hodonín, Czech Republic). The treatise contains an analysis of transformations that the custom has undergone for the quite short time of its existence. Attention was paid both to the initiating impetuses and motivations leading to the revival, and to the role of persons and groups that have taken part in organizing the custom. One of the major objectives was to analyse the social and other functions that the Královničky (tied to Pentecost) are fulfilling towards the actors and the whole local community.
Housing for Farmers: the Adaptation of Urban Housing Standards to the Environment of Rural Settlements
Authors:   Ústav evropské etnologie Filozofické fakulty Masarykovy univerzity, Drápala Daniel
Published: July 2023

Housing construction in Czechoslovakia began to grow in the 1940s, which was reflected in the increased number of flats and improved housing standards. This growth was made possible mainly due to the construction of blocks of flats. Although in the countryside, in contrast to the cities, people predominantly lived in their own family houses, the construction of apartment blocks also contributed to the increase in capacity there. However, the experience from the 1940s and 1950s shows negative impacts of adopting the projects for blocks of flats which were designed for the city and the urban way of life and did not suit rural residents, who had different working patterns and needs. In the 1960s, an intensive dialogue between local participants, architects, and the authorities took place, leading to the adaptation of the apartment block concept to the needs of agricultural workers. The adaption concerned both the external appearance, which had to respect the village environment, and the internal layout. The adapted projects included separate rooms for residents to wash themselves after their return from fields and gardens, and storage compartments for foods and livestock feed. Attention was also paid to the surroundings, where buildings related to residents’ farming activities were designed (small animal breeding, working in the gardens and small fields). The willingness to conduct the dialogue and to adapt the projects for rural blocks of flats disappeared in the 1970s as a result of the normalization and gradual improvement in agricultural workers’ living standards.
Deluge, Pain, Agony, and Survival: Decoding Disaster’s Adversities
Authors: R. Eslit Edgar
Published: July 2023

This article aimed to explore the experiences of deluge victims in Iligan City following Typhoon Sending using Interpretative Phenomenological Analysis (IPA). Semi-structured interviews were conducted with 10 participants, and the data were analyzed using IPA. The study found that the flood had a significant psychological and emotional impact on the participants, with several key themes and patterns emerging from the IPA analysis. These included the impact on emotional well-being, coping strategies, and patterns of adaptation and adjustment among Iligan City’s Sending Survivors. The coping strategies employed by the participants highlighted the importance of social support and community engagement in disaster recovery. The patterns of adaptation and adjustment observed among the participants suggest the potential for personal growth and development following a traumatic event. The study has implications for practitioners and policymakers involved in disaster response and recovery, and highlights the need for continued research and support for individuals and communities affected by natural disasters.
Effects of Availability and Access to Safe Drinking Water on Students’ Academic Performance in Secondary Schools in Muhoroni Sub-County, Kenya
Authors:   University of Eldoret, Sang Ednah Jepkoech , Omuse Emoit
Published: July 2023

Access to improved sanitation is an important component of human health and wellbeing. Minimum requirements for safe WASH in schools are not provided in most rural schools in Kenya. The current paper investigated the effects of availability and access to safe drinking water on students’ academic performance in secondary school in Muhoroni Sub-County, Kenya. Descriptive research design and mixed methodology was used. The target population was 2354 form three students and 23 teachers. Krejcie and Morgan sample size determination formula was used to obtain a sample size of 331 respondents. Questionnaires and interviews were used to collect data. Validity was determined by consulting research supervisors while reliability was determined through the use of Cronbach Alpha. Quantitative data were analysed by SPSS (version 25) and the findings presented using frequencies and percentages while qualitative data were thematically classified and arranged before they were reported in narrations and quotations. The study found that 65.4% of the learners reported that they were using safe drinking water in their schools. In addition, 63.3% of the study participants reported that their schools had reliable, sufficient and clean water supply. The study concluded that availability of safe drinking water at schools reduces the likelihood of water-related illnesses, such as diarrhea or other waterborne diseases. In addition, availability to sanitation facilities influence students’ academic performance among secondary school students. This study will give the current WASH scenario of schools in the study area that can help concerned authorities abide by WASH guidelines to improve the school’s WASH situation.
Tinjauan Atas Akuntansi Pajak Tangguhan pada PT. KAI (Persero) Kantor Pusat Bandung
Authors: Abdurokhim Abdurokhim
Published: July 2023

Masalah utama perlakuan akuntansi pajak penghasilan adalah bagaimana mempertanggungjawabkan konsekuensi pajak pada periode berjalan dan periode mendatang untuk pemulihan nilai tercatat aset dan kewajiban. Serta transaksi kejadian lainnya pada periode berjalan yang diakui pada laporan keuangan perusahaan. Pengakuan ini mengharuskan perusahaan mengakui aset dan kewajiban pajak tangguhan. Tujuan dari penelitian ini adalah untuk mengetahui pengakuan awal, pengukuran, pencatatan dan penyajian pajak tangguhan dalam laporan keuangan PT. KAI (Persero) Kantor Pusat. Metode penelitian yang digunakan dalam penelitian ini adalah penelitian perpustakaan (library research) dan penelitian lapangan (field research). Penelitian ini dilaksanakan di PT. KAI (Persero) yang beralamatkan di Jl.Perintis Kemerdekaan No.1 Bandung. Hasil penelitian ini menunjukkan bahwa PT. KAI (Persero) telah melakukan pengakuan, pengukuran, pencatatan, dan penyajian aset pajak tangguhan telah sinkron dengan PSAK No. 46 dan buku teori khususnya tentang akuntansi retribusi honorarium
Analisis Rasio Aktivitas pada CV. HMZ
Authors: Fariah Aen
Published: July 2023

CV. HMZ merupakan perusahaan yang bergerak dalam bidang industri retail yang menjual barang berupa busana, nonbusana dan kosmetik. Dengan perkembangan zaman sekarang yang telah berkembang dan seiring majunya teknologi maka perusahaan dituntut harus dapat mengembangkan usahanya dengan semaksimal mungkin. Maka perusahaan dituntut untuk menampilkan yang terbaik dalam segi kinerja dan ditunjang dengan manajamen keuangan yang baik. Selain itu, perusahaan juga memerlukan adanya penganalisisan laporan keuangan untuk mengetahui kemampuan perusahaan dalam mengatasi masalah-masalah yang berkaitan dengan keuangan perusahaan. Tujuan penelitian ini adalah untuk mengetahui receivable turnover, total aset turnover dan inventory turnover perusahaan periode 2015-2017. Model penelitian yang dilakukan adalah penelitian lapangan (field research). Menganalis laporan keuangan denganpenelitian pustaka (library research). Hasil penelitian menunjukan bahwa rasio aktivitas mengalami penurunan dan peningkatan (tidak stabil) Jika dilihat dari rasio aktivitasnya adalah kurang efisien, hal ini terbukti bahwa perusahaan gagal dalam perencanaan dan pelaksanaan strategi untuk peningkatan  keuntungan perusahaan, perusahaan tidak dapat menagih piutangnya dan perusahaan tidak mampu dalam memanfatkan aset aset yang dimilikinya. Hal ini dapat berakibat pada
penurunan keuntungan di masa depan. Berdasarkan perhitungan receivable turnover inventory turnover dan total asset tunrover pada setiap tahun mengalami penurunan dibawah minimum standar industri, ini artinya perusahaan terlalu menahan persediaan berlebihan, penagihan piutang yang kurang efektif dan kurangnya pemanfaatan terhadap aset-aset yang tersedia di perusahaan.
Pengaruh Latar Belakang Pendidikan Siswa Paket Terhadap Prestasi Belajar pada Pelajaran PAI
Authors: Abdullah Abdullah
Published: July 2023

Masalah pendidikan tidak akan pernah selesai untuk dibicarakan. Karena soal pendidikan akan selalu terkait dengan konstektualitas kehidupan umat manusia sepanjang zaman. Setiap perkembangan peradaban umat manusia sudah barang tentu selalu diikuti oleh berbagai dimensi kehidupan manusia itu sendiri. Dengan demikian masalah pendidikan ini mempunyai arti dan definisi serta istilah yang berbeda-beda Sekolah merupakan pendidikan formal. Penelitian ini bertujuan untuk mengetahui dampak pendidikan siswa paket B dengan hasil prestasi belajar di mata Pelajaran Pendidikan Agama Islam (PAI). Penelitian ini dilakukan dengan metode uji normalitas. Tugasnya adalah mengembangkan kemampuan, bakat, dan minat anak atau siswa secara optimal sesuai dengan potensinya. Dengan pengembangan tersebut, siswa menjadi manusia yang berguna baik bagi dirinya maupun bagi orang lain atau lingkungannya. Oleh karena itu, setiap anak yang akan melanjutkan sekolah ke jenjang yang lebih tinggi, membutuhkan penyesuaian diri dengan latar belakang pendidikan yang dia tempuh sebelumnya. Sebagai contoh, siswa yang mempunyai latar belakang pendidikan dari Madrasah Ibtidaiyah (MI) sebaiknya atau idealnya melanjutkan ke Madrasah Tsanawiyah (MTs), sedangkan bagi siswa yang mempunyai latar belakang pendidikan dari Sekolah Dasar (SD) sebaiknya atau idealnya melanjutkan ke Sekolah Menengah Tingkat Pertama (SMP) ataupun ke lembaga pendidikan non formal seperti PKBM Paket B Hidayatul Mubtadiin. Akan tetapi dalam kenyataannya, tidak seluruh siswa itu dapat melanjutkan sekolah sesuai dengan latar belakang pendidikannya. Hal ini disebabkan oleh beberapa alasan.Apabila salah satu faktor di atas mengalami hambatan, maka hasil belajar siswa pun terpengaruhi.
Pemanfaatan E-Commerce Bagi UMKM pada Era Industri 4.0
Authors: Berliana Irda , Ompusunggu Dicky Perwira
Published: July 2023

Dunia saat ini memasuki era industri 4.0 yang berfokus pada pola digital economic, artificial intelligence, big data, robotic, dan teknologi lainnya. E-commerce merupakan penghubung antara teknologi informasi dalam pemasaran dan pendistribusian produk yang berpotensi meningkatkan skala kinerja UMKM. Dengan memanfaatkan e-commerce, UMKM tetap dapat menjalankan bisnis dan menjangkau banyak konsumen serta memperluas pangsa pasar. Penelitian ini bertujuan untuk membahas tenang pemanfaatan e-commerce bagi UMKM pada era industri 4.0. Penelitian ini mengunakan pendekatan studi kepustakaan dengan mengamati  dan menganalisis semua informasi mengenai topik penelitian. Pemanfaatan e-commerce bagi UMKM menyebabkan UMKM mampu untuk memasarkan barang dan jasa yang mereka miliki baik secara fisik maupun digital. Di era industri 4.0 memberikan banyak dampak positif pada e-commerce, sehingga prospek pertumbuhan e-commerce dimasa mendatang akan meningkat. E-commerce dan industri 4.0 memiliki hubungan yang selaras dan berbanding lurus, karena teknologi e-commerce akan beradaptasi dengan teknologi saat ini pada era industri 4.0.
Securing the Internet of Things: A review of Lightweight and low-power Cryptography Techniques
Authors: Abdulrazzaq H.A. Al-ahdal  , Mouad M.H. Ali  , Abdullah Alahdal  , Arafat S.M. Qaed  , Galal A. Al-Rummana
Published: July 2023

The current information related to security and IoT by conducting a theoretical and methodological study. It provides a detailed explanation on what is the meaning of IoT and on the various applications in IoT. It also presents the major issue of the security of IoT for applications. Moreover, the chapter discusses the metrics that define lightweight algorithms in hardware and software, and it presents the reasons for choosing blocks in lightweight algorithms and studying the architecture of those blocks. It also refers to the blocks/algorithms, both the traditional ones and the lightweight ones.
FORMATION, PROBLEMS AND PROSPECTS FOR THE DEVELOPMENT OF THE METHODOLOGY FOR STUDYING LOCAL POLITICAL REGIMES IN UKRAINE: A MAXIMALIST APPROACH
Authors: Rishko Stepan
Published: July 2023

The relevance of the study of local political regimes in Ukraine has been growing since the 2010s. This is due to the need to predict the behavior of the local political actors after the transfer of a large number of authorities to them due to the reform of decentralization of power. In addition, practical studies of local political regimes make it possible to highlight the main features of formal and informal relationships between local political actors and with the central government, covering the essence and effects of the process of decentralization of power in Ukraine. In this sense, the purpose of the article is to determine the key parameters of local political regimes; analysis of the methods used by Ukrainian scientists when studying local political regimes in Ukraine; defining parameters for comparing local political regimes in the Ukrainian context based on a maximalist approach. Based on the results of the study, a periodization of existing studies of local political regimes in Ukraine is proposed, in particular, taking into account existing studies in the format of case studies and regional comparisons. Based on them, the key parameters for the formation of a methodology for comparing local political regimes are identified, which should include indices and indicators for analyzing democracy and the level of decentralization of power within the local regime, as well as identifying the influence of local authorities, business and civil society on the process of forming the agenda and determining strategic directions of socio-economic growth.
Features of theorization, verification and structuring of regionalism as a possible basis for the politicization of ethnicity in Ukraine in 1991-2013 and before the Russian-Ukrainian war.
Authors: Białobłocki Tomasz
Published: July 2023

The article analyzes the features of theorization, verification and structuring of regionalism and regionalization as a possible basis for politicization of ethnicity in Ukraine in 1991-2013, i.e. before the Russian-Ukrainian war, in particular in its local phase since 2014 and in large-scale phase since 2022.This is done at the background of the statement that aggressive Russia has always proceeded from the ideological and propagandistic (including instilled in Ukraine) assumption that Ukraine is not a united and consolidated country, because it has historically been characterized by regionalism and regionalization, which Russia expects should were the basis for the politicization of ethnicity and the ethnolinguistic issue in Ukraine in 1991-2013. However, as the political and military practice of 2014-2022 showed, this calculation turned out to be largely erroneous and incomparable with the electoral, religious, linguistic, ethnic and other socio-political cleavages that historically characterized (and significantly were overestimated by Russia) post-Soviet Ukraine. To demonstrate this, various approaches to understanding and organizing regionalism in Ukraine were proposed, including two-component, four-component, eight-component, etc., each of which was structured and characterized. The author argued that any attempt to use the idea of regionalization of Ukraine – especially in its twofold logic (divided into “West” and “East” or the Right Bank and the Left Bank relative to the Dnipro River) – in the real socio-political process in this country, but especially in the context of the Russian-Ukrainian war, which began in 2014 and intensified on a large scale in 2022, failed. However, this does not mean that the issue of regionalism and regionalization in Ukraine should not be continued and developed, but in a completely different way and direction, especially in the context of European integration of this country.
ELECTORAL AND PARLIAMENTARY PARTIES IN DEMOCRATIC COUNTRIES: POLITICAL AND INSTITUTIONAL PERSPECTIVES ON THE DEFINITION AND ARRANGEMENT OF RELATIONS
Authors:   Akademia Nauk Stosowanych Gospodarki Krajowej, Moszczyńska Aneta
Published: July 2023

The article analyzes and systematizes different political and institutional perspectives of defining and arrangement of relations between electoral and parliamentary parties, as well as the options of distinguishing between them in representative democracies. This is done in view of the fact that parties in representative democracies play a major role in organizing and articulating the demands, interests and needs of different groups of voters. Accordingly, the issue of theorizing and understanding political and institutional perspectives of defining and arrangement of relations between parties as participants in elections and fractions as parties in the parliaments of almost all democratic countries in the world was put on the agenda. To do this, the author analyzed and structured the differences between such notions as “party”, “electoral party”, “parliamentary party”, “faction”, “caucus” and “coalition”.
The features of legislative process in the countries of the visegrad group: a descriptive and comparative analysis
Authors:   Akademia Nauk Stosowanych Gospodarki Krajowej, Moszczyńska Aneta
Published: July 2023

The article is dedicated to analyzing, comparison and synthesis of the features of legislative process in the countries of the Visegrad group. It was emphasized on a descriptive and comparative analysis of the proposed cases. The researcher motivated that the countries of the Visegrad group are nominally and practically characterized by variational procedures and patterns of legislative process. This is determined by the fact that there are unicameral (more legislatively stable) and bicameral (more legislatively volatile) legislatures in the region, which use different procedures of legislative process. Although it was recognized that in general (in the case of the unicameral and bicameral parliaments of the countries of the Visegrad Group) legislative process is largely implemented in the same way, but with some differences.
The Physiological Changes In The Postpartum Period After Childbirth
Authors: Martin Christian , Viky Muhammad , Rokibullah Rokibullah , Sofinia Haleyoan
Published: July 2023

The physiological changes that occur during the puerperium are very clear, where the process of pregnancy goes in reverse. Physiological changes that occur during pregnancy will return to normal during the postpartum period. Pregnancy and childbirth are physical events, so the concept is that during the puerperium the body will recover. This study aims to provide an explanation of the physiological changes during the puerperium after childbirth and to add insight in describing precisely and training the scientific thinking needed to be able to analyze a problem accurately and quickly. This study used the contrast review method, meaning the journal review method by finding differences between several research journals and then drawing conclusions. The results of this study found that there were several physiological changes during the postpartum period including changes in the reproductive system, changes in the endocrine system, changes in vital signs, changes in the cardiovascular system, changes in the blood circulation system, changes in the hematological system, and changes in the respiratory system.
Pengaruh Level Substitusi Rumput (Bothiriochola Pertusa) dengan Kangkung Terhadap pH, Konsentrasi VFA dan Amonia Cairan Rumen Ternak Kambing Kacang
Authors: Leo Sepni , Maranatha Grace , Oematan Gustaf
Published: July 2023

This study was aimed to determine the effect of substitution level of Bothhriochloa pertusa grass with water spinach on pH, Volatile Fatty Acid, Concentration and ammonia in rumen fluid of peanut goat livestock. This study used 4 male kacang goats aged 8-1,5 years with a body weight range of 13,3-19,8 kg with an average of 16,2 kg. This study used a Latin Square design (RBSL)  with four treatments and four replication periods. The four treatments were P0: Bothriochloa pertusa grass 60% + leucaena leucochephala 40%, P1: Bothriochloa pertusa grass 45% + leucaena leucochephala 40% + water spinach 15%, P2: Bothriochloa pertusa grass 30% + leucaena leucochephala 40% + water spinach 30%, P3: Botriochloa pertusa grass 15% + leucaena leucochephala 40% + water spinach  45%. Parameters measured were pH, Vollatile Fatty Acid (VFA) and Ammonia (NH3). The data obtained were analysed using Analisis of Variace (ANOVA. The results of this study indicate that pH, P0: 5.89 ± 0.22b, P1: 5,82 ± 0,1b, P2: 5,72 ± 0,17ab,  P3: 5,57  ± 0,1a . VFA (mM), P0: 132,03 ± 3,99a, P1: 127,14 ± 3,99a, P2: 129,58 ± 6,31a, P3: 132,76 ± 4,95a.  NH3 (mg/dl), P0: 15,89 ± 2,12a, P1: 15,14 ± 0,97a, P2: 15,52 ± 2,45a, P3: 16,41 ± 0,1a. The results of statistical analysis showed that the effect was not significant on the concentration of pH, concentration of VFA and rumen fluid ammonia of peanut goads. The conclusion of this study is that the substitusion of Bothriochloa pertusa grass with water spinach at different levels has the same effect between the treatments on pH, VFA concentration and rumen fluid ammonia of male peanut goat.
IMPNS Computations of the X-15 Flight Vehicle: A Validation and Verification
Authors:   School of Engineering, Cranfield University, Cranfield, Bedfordshire MK43 0AL, Shaw S. , Mifsud M. ,   School of Engineering, Cranfield University, Cranfield, Bedfordshire MK43 0AL, Wagner B. ,   School of Engineering, Cranfield University, Cranfield, Bedfordshire MK43 0AL, Moureaux A. ,   School of Engineering, Cranfield University, Cranfield, Bedfordshire MK43 0AL, Bennett J. ,   School of Engineering, Cranfield University, Cranfield, Bedfordshire MK43 0AL
Published: July 2023

A verification and validation study of the IMPNS space-marching flow solver has been undertaken for a complete hypersonic air-vehicle configuration. A hierarchical approach was adopted in which the vehicle aerodynamics was decomposed and related flow phenomenon studied. Using this hierarchy benchmark solutions and laboratory experiments were identified that provide the basis of the verification and validation exercises. Detailed comparisons of iterative and grid converged IMPNS computations with benchmark solutions and wind tunnel measurements are presented. Computations of the X-15 wind tunnel and flight experiments are described and comparison is made with measured surface and off-surface pressure measurements and wind tunnel flow visualization observations that demonstrate the reliability and capability of the IMPNS flow solver for complex configurations.
Validation of Experimental Results of a Realistic Natural Laminar Swept Wing through Advanced Stability Methods
Authors:   CIRA, Italy, de Rosa D. , Donelli R. ,   CIRA, Italy, Romano D. ,   Piaggio Aero Industries S.p.A., Italy
Published: July 2023

In a study by Ma et al. (2010), an innovative honeycomb heatsink design for an LED lighting system was analysed using computational fluid dynamics (CFD) and experimentation. The previous simulation results were replicated using an immersed boundary approach, validating the code against that used in the earlier study. When we looked critically at the images of the experiment in Ma et al. (2010), we noted some discrepancies between the simulation model and the experimental setup. Although the experimental setup was not fully described, we were able to identify a number of issues and make near-exact estimates of the dimensions and other values needed to include their effects in the simulation. The resulting simulation matched the test data very well. In this paper, we present the rationale for applying a different approach that is commonly used in electronics thermal design. We also describe the different aspects of the alternative CFD technology used, as these will not be familiar to most readers, to describe how it can handle fluid flow and heat transfer within complex geometries without simplification. These benefits are illustrated using the honeycomb heatsink example.
Numerical Investigation of Droplet Distribution from a Pre-filming Air-blast Atomizer
Authors:   Centre for Rotating Machinery Design, M S Ramaiah School of Advanced Studies. Bangalore, India, Poovanna C. , Sridhara S. ,   Centre for Rotating Machinery Design, M S Ramaiah School of Advanced Studies. Bangalore, India.
Published: July 2023

The combustion characteristics and emission from a gas turbine greatly depends on the spray characteristics. Pre-filming air-blast atomizers are commonly used in gas turbines due to their high spray cone angle and shorter atomization axial distance when compared to direct air-blast atomizers. Various numerical models are available in the open literature for predicting droplet characteristics. In the present study commercial code FLUENT 6.3 is used to predict the spray characteristics. The numerical results are validated against experimental results and further the spray characteristics in terms of radial Sauter mean diameter (SMD), mass flux distribution at varied axial distance and swirl number (S) have been discussed. The variation of predicted SMD with swirl number demonstrated a decrease in its value for each level of increase in the swirl number. Smaller droplets start to appear further downstream in addition to significant increase in radial spread of droplets. Negligible mass contribution from the smaller droplets at the boundary compared to that from bigger droplets at the centre was observed. Recessing the liquid tube at the exit of air nozzles showed a slight decrease in SMD. Recessing the liquid tube in the exit air nozzles results in a slight in SMD values, hence, the recessing of liquid post in the atomizer within certain limit might be beneficial not only helping in flame holding but also resulting in finer spray. The lessons learnt from this study on use of CFD for simulating the atomization process is highlighted.
Water in Fuel Sloshing for Aircraft Fuel Tanks
Authors:   University of the West of England, UK, Hylands G. ,   Airbus Operations Ltd., UK, Toomer C. ,   University of the West of England, UK, Lam J. ,   Airbus Operations Ltd., UK
Published: July 2023

Water is an unavoidable contaminant in aircraft fuel tanks. During an aircraft manoeuvre, fuel and water will slosh. The sloshing of two liquids (two-liquid sloshing) gives rise to a number of interesting phenomena which single-liquid sloshing does not experience. These include internal waves at the liquid-liquid interface and interaction between the motions of the two liquids. This paper investigated the ability of three commercial Computational Fluid Dynamics (CFD) modelling packages to accurately predict the pressures imparted on the tank walls of a rectangular tank when excited at near-resonant frequency while containing two liquids; water and fuel. A sloshing test rig was set-up to provide both qualitative (visual images) and quantitative (pressure data) results for comparison with the CFD calculations. The CFD calculations correlated well with the experimental results qualitatively and quantitatively. Snapshots of the sloshing show that CFD is able to model the wave modes reasonably well; and the pressure data show that CFD is able to simulate the pressure them were postulated.
CµFD: Simulation of Microfluidic Systems
Authors:   Fluidics and Simulation Department, Institut für Mikrotechnik Mainz GmbH - IMM, Schönfeld F. , Drese K. ,   Fluidics and Simulation Department, Institut für Mikrotechnik Mainz GmbH - IMM, Hardt S. ,   Chair of Technical Thermodynamics, Darmstadt University of Technology, Germany
Published: July 2023

We discuss the applicability of standard CFD techniques in µ-fluidics, highlight challenges and introduce methods which allow for corresponding extensions. The focus is especially on problems of major practical importance, namely liquid mixing in micro mixers and free-surface micro flows. With respect to the former two approaches are presented allowing eliminating the problems due to numerical discretisation errors for specific cases of miscible liquids. In the case of emulsion formation of immiscible liquids the RayleighPlateau decay is identified to be the driving mechanism for droplet formation under certain process conditions. Furthermore we investigate capillary filling of a narrow slit, where a special focus is put on the effects induced by a dynamic variation of the contact angle. The test case shows that on practically manageable grids the dynamic behaviour of the contact angle cannot be sufficiently reproduced. A result of the studies performed is the possibility to incorporate the correct contact-angle dynamics even on comparatively coarse grids by introducing a macroscopic slip range at the 3-phase contact line. By virtue of such an “artificial slip method”, correct results for free-surface micro flows can be obtained on grids with a moderate number of computational cells, without the need to resolve the contact line very accurately. Finally, a micro fluidic application involving both mixing of miscible liquids and free-surface flows is exemplarily outlined as one of the future challenges.
Simulation of the Efficiency of Static Mixers
Authors:   Sulzer Markets and Technology AG, Sulzer Innotec, Winterthur, Switzerland, Schöck J , Muggli F. ,   Sulzer Markets and Technology AG, Sulzer Innotec, Winterthur, Switzerland, Hirschberg S. ,   Sulzer Chemtech, Winterthur, Switzerland
Published: July 2023

Within the Sulzer Corporation the behavior and efficiency of static mixers is predicted by means of CFD. Typical mixers are the SMX mixer and the CompaX mixer. As the SMX mixer is used for laminar mixing and homogenization of high viscous fluids, the CompaX mixer is applied for turbulent flow regimes. Simulations carried out for these mixers have been validated with measurements. Key values to evaluate the efficiency are the pressure loss and mixing quality. The pressure loss for both mixer types can be directly gained from the CFD simulation. But it is not possible to predict the mixing quality of laminar mixers directly from CFD simulations as for laminar flows the numerical diffusion is significantly higher than the real molecular diffusion. Thus, to predict the mixing quality of laminar mixers a trajectory method is applied. The molecular diffusion along the trajectories is taken into consideration by a Monte Carlo method. For turbulent flows diffusive mass transfer plays only a minor role. Therefore, the mixing quality can be gained directly from the CFD simulation. Furthermore, for structural analysis the forces acting on the mixer elements induced by the flow, the residence time distribution of fluid elements in the mixer and heat exchange with the duct wall is of particular interest.
Calculation of the characteristic diagram of an axial fan using CFD
Authors:   TLT Turbo GmbH, 66482 Zweibruecken, Germany, Wolfanger T. , Lenartz M. ,   TLT Turbo GmbH, 66482 Zweibruecken, Germany
Published: July 2023

The characteristic curves of a ventilator with adjustable blade angle were calculated using CFD. The characteristic curve is valid for a certain blade angle of a single stage ventilator and was measured on a test stand according to DIN 24163. To evaluate the critical points for the calculation of the characteristic curves, a number of blade angles have been considered. It turned out that the points with the maximum deviation between measurement and calculation were lying close to the optimum efficiency point of the fan operation in the vicinity of the separation line. For further studies of the influence of mesh resolution, turbulence modelling and geometric modelling, one operation point showing relatively large deviations from the measurements was chosen. For this operation point, a successive refinement of the mesh was done to get a grid independent solution. The mesh of the grid independent solution was used to study the influence of several turbulence models including two equation k-ε and k-ω models and a ω based Reynolds stress model and the influence of the blade tip gap. Finally, one curve from the characteristic diagram was recalculated using the best performing turbulence model and the results were compared to measurements.
Simulation of Turbulent Swirling Flows: Gas Turbine Combustor Application and Validation
Authors:   Düsseldorf University of Applied Sciences, Düsseldorf, Germany, Benim A. , Stopford P. ,   ANSYS Europe, Oxfordshire, UK, Buchanan E. ,   Siemens Industrial Turbomachinery Ltd., Lincoln, UK, Syed K. ,   Siemens Industrial Turbomachinery Ltd., Lincoln, UK
Published: July 2023

In the first part of the paper, CFD analysis of the combusting flow within a high-swirl lean premixed gas turbine combustor and over the 1st row nozzle guide vanes is presented. In this analysis, the focus of the investigation is the fluid dynamics at the combustor/turbine interface and its impact on the turbine. The predictions show the existence of a highly-rotating vortex core in the combustor, which is in strong interaction with the turbine nozzle guide vanes. This has been observed to be in agreement with the temperature indicated by thermal paint observations. The results suggest that swirling flow vortex core transition phenomena play a very important role in gas turbine combustors with modern lean-premixed dry low emissions technology. As the predictability of vortex core transition phenomena has not yet sufficiently been investigated, a fundamental validation study has been initiated, with the aim of validating the predictive capability of currently-available modelling procedures for turbulent swirling flows near the sub/supercritical vortex core transition. In the second part of the paper, results are presented, which analyse such transitional turbulent swirling flows in a laboratory water test rig. It has been observed that turbulent swirling flows of interest are dominated by low-frequency transient motion of coherent structures, which can not be adequately simulated within the framework of steady-state RANS turbulence modelling approaches. It has been found that useful results can be obtained only by modelling strategies, which resolve the three-dimensional, transient motion of coherent structures, and do not assume a scalar turbulent viscosity at all scales. These models include RSM based URANS procedures as well as LES. To exploit the full potential of LES, however, additional attention needs to be paid to modelling issues such as achieving the necessary grid resolution as well as providing convenient inlet boundary conditions.
Computational Fluid Dynamics Validation Utilizing a Tracer Gas Study Related to a Mine Mill Area Toxic Gas Release for Emergency Response Planning
Authors:   Chemistry & Industrial Hygiene, Inc. 10201 W. 43 Ave., Wheat Ridge, CO 80033, USA, Hall D. , Strode C. ,   Chemistry & Industrial Hygiene, Inc. 10201 W. 43 Ave., Wheat Ridge, CO 80033, USA, Rasmuson J. ,   Chemistry & Industrial Hygiene, Inc. 10201 W. 43 Ave., Wheat Ridge, CO 80033, USA, Korchevskiy A. ,   Chemistry & Industrial Hygiene, Inc. 10201 W. 43 Ave., Wheat Ridge, CO 80033, USA, Strode R. ,   Chemistry & Industrial Hygiene, Inc. 10201 W. 43 Ave., Wheat Ridge, CO 80033, USA
Published: July 2023

Many dispersion models (e.g. DEGADIS, SLAB, INPUFF, and ALOHA) have been developed by regulatory agencies for emergency response related to dense toxic gas releases. The National Oceanic and Atmospheric Administration’s (NOAA) Area Locations of Hazardous Atmospheres (ALOHA) software is an example one such model. However, such models typically over-predict dense toxic gas plume dispersion concentrations and do not take into account complex terrain or complex building canyon geometries. This creates imprecise and inaccurate emergency response plans for industries that utilize such gases for production processes. The application of Computational Fluid Dynamics (CFD) mostly overcomes these challenges and provides a refined understanding of dense gas plume dispersion. Evaluating micro-scale atmospheric models is typically conducted in a wind tunnel tracer gas experiment; however, the one-hour tracer gas experiments utilized in this study evaluation were conducted in a real-world, full-scale, industrial setting. These same industries are often faced with worker health risks related to airborne respirable particulates and fibers with low settling velocities and where transport is dominated by air movement. Thus, it is anticipated that this evaluation may be applied to exposure characterization and risk assessment.
Coal Combustion - Partial Validation of a Complex Problem
Authors:   RWE npower, Windmill Hill Business Park, Whitehill Way, Swindon, Wiltshire, SN5 6PB, Stephenson P.
Published: July 2023

This paper summarises efforts made over a number of years to apply CFD to coal combustion in the Combustion Test Facility (CTF) currently owned and operated by RWE npower. It formed a key part of a strategy to develop a CFD capability in this area. The first two applications (to a drop tube furnace and to the CTF fitted with one type of burner) were successful. However, a subsequent application (the CTF with a completely different burner) had only limited success. The precise reasons for this limited success apply solely to this particular application. However, the work raised two questions that are relevant to any industrial application of a commercial CFD code. Therefore the aim of this paper is to provide an overview of this work and to use the experience gained to discuss two questions...
Prediction of Turbulent Heat Transfer for Industrial Drying Processes – Turbulence Model Assessment
Authors:   Fraunhofer Institute for Manufacturing Engineering and Automation, Nobelstr. 12, 70569 Stuttgart, Germany, Ye Q. , Pulli K. ,   Fraunhofer Institute for Manufacturing Engineering and Automation, Nobelstr. 12, 70569 Stuttgart, Germany, Scheibe A. ,   Fraunhofer Institute for Manufacturing Engineering and Automation, Nobelstr. 12, 70569 Stuttgart, Germany
Published: July 2023

This paper presents numerical investigations of turbulent heat transfer for industrial drying processes. The CFD code FLUENT was applied. The performance of various turbulence models, especially the grid sensitivity to the prediction of the Nusselt number, was tested using available experimental data of single jet impingement and the DNS data of channel flow. The sst-kˆ turbulence model with enhanced wall function that was found to give a reasonably accurate prediction of heat transfer with lower grid sensitivity was applied to the flow calculation in dryers. Flat sheets as well as more complicated geometries of substrates, for instance, a truck chassis were used in the simulations. The calculated heating-up behaviour on the substrates was compared with experimental results.
A Weak Compressible Flow Solution for Fluid and Air-Borne Acoustics Coupled Problems in a Nonlinear System
Authors:   ESI Group, Rungis, France, Zhu M. , Tabbal A. ,   ESI Group, Rungis, France, Megahed M. ,   ESI Group, Rungis, France, Pierrot G. ,   ESI Group, Rungis, France, Ravier P. ,   ESI Group, Rungis, France
Published: July 2023

This paper presents the implementation and validation of a numerical simulation method that takes into account the air-borne acoustic wave propagation within the turbulent flow solution at low Mach numbers. The method is called weak compressibility, and is used in order to cope with fully coupled aero-acoustics problem in a nonlinear system. The weak compressibility was implemented into an explicit incompressible flow solver using an edgebased finite element method. A single 3D cavity case was used to validate the method in comparison with the experiment. The simulated results showed good agreement with the experimental data with regards to the acoustic pressure and frequency for the dominant peak of the sound pressure level (SPL) spectra over a wide speed range from 15 to 55 meters per second.
Dynamic Simulation of Flight Test Manoeuvres on the Diamond D-Jet
Authors:   Diamond Aircraft Industries, Van Bavel L. , Holman D. ,   Next Limit Technologies, Brionnaud R. ,   Next Limit Technologies, García-Camprubí M. ,   Next Limit Technologies
Published: July 2023

The numerical simulation of the complex fluid-structure interaction taking place when manoeuvring an aircraft remains a challenge. A realistic analysis of the airplane manoeuvrability often involves the presence of moving parts, such as the deflection of the elevators, the ailerons, or the elevons. For conventional Computational Fluid Dynamics (CFD) codes, dealing with such moving geometries is a challenging task. The following work uses software based on the lattice-Boltzmann method (LBM) to overcome these issues. This paper presents a numerical study on the dynamic simulation of flight test manoeuvres on the Diamond D-JET, using the XFlow virtual wind tunnel. The pitch capture manoeuvre is first simulated, studying the pitch oscillation response of the aircraft. Dutch roll flight mode is then numerically reproduced. Finally, the D-JET angle of attack is evaluated in the poststall regime under controlled movements of the elevator. Numerical results are eventually compared with the corresponding flight test data recorded by Diamond Aircraft Industries. Numerical and experimental results show reasonable agreement. It may thus be concluded that: (i) the LBM can offer the opportunity to bypass some wind tunnel testing; and (ii) the LBM can complement flight tests by helping in mitigating risks associated with flight test manoeuvres, including fully developed stalls and spin testing.
Optimization of a Sanding System for a Tramway Car by Numerical Simulation of the Sand-Air Two-Phase Flow
Authors:   Competence Center - The Virtual Vehicle (ViF), Graz, Austria, Möller S. , Langmayr D. ,   ANSYS Germany GmbH, Otterfing, Brenn G. ,   Institute of Fluid Mechanics and Heat Transfer (ISW), TU Graz, Krieg P. ,   KNORR-BREMSE GmbH, Mödling
Published: July 2023

In tramways, sanding systems are used to avoid gliding while accelerating or slowing down the vehicle under bad rail conditions. The total amount of sand required should be a minimum to reduce costs and unnecessary formation of particulate matter in road traffic. The main aim of the present paper is to minimize this total amount of sand by means of modern computational methods. For this purpose, the software ANSYS FLUENT is used to develop a numerical simulation model, which allows the flow of a sand-air mixture to be simulated under the conditions of a sanding system. Of particular importance in the approximation to reality is the correct modelling of the rebound behavior of the sand particles on the surface of the rails. For an accurate prediction of the related physics, a stochastic sub-model was implemented whose parameters were tuned using results from in-house experiments carried out for this purpose. A series of simulation computations led to suggestions of improved design variants of the end piece at the exit of the sanding device and a better focused sand jet. Finally, the improved end pieces were tested in simulations with approximated realistic geometry and boundary conditions.
Digital Prototyping Methodology for Cyclonic Multiphase Flow Separation
Authors:   Eaton Technologies Pvt. Ltd., India, Kulkarni A. , Kulkarni M. ,   Eaton Technologies Pvt. Ltd., India, More P. ,   Eaton Technologies Pvt. Ltd., India, Showalter S. ,   Eaton Corporation, USA
Published: July 2023

Safety and reliability are fundamental requirements for gas turbine engines. Continuous health monitoring and diagnostics devices are prime enablers for the same, and gaining a lot of attention for advancements. Oil debris monitoring is one of the important elements of an engine condition monitoring system. The cyclone separator is the key component of the debris monitoring system which separates air, oil and solid particles. The separation efficiency of various phases determines the cyclone performance and is governed by highly turbulent swirling flow field. Further, the particle capture efficiency depends on successful capturing of the flow field. Cyclone performance enhancement requires a detailed understanding of turbulent swirling multiphase flow field with free and forced vortex interactions. This poses a significant challenge for physical prototyping and demands detailed computational models to resolve the anisotropic structure of a turbulent flow field with multiphase interaction. Detailed investigation of various computational models such as turbulence models, multiphase models, and drag models has been carried out to capture the complex flow physics. A structured computational approach helped to establish a CFD methodology having a close match with experimental findings for all the performance parameters of three phase separation. The methodology is validated with the experimental results with the variation between CFD and experiments observed to be less than 10% for all four performance parameters namely pressure drop, air separation efficiency, oil separation efficiency and particle capture efficiency.