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Abstrak :
Summary: A unified theory of multiphase flows, providing tools for practical applications

Abstrak :
This Handbook provides readers with the current cutting edge of multiphase flow technology. It reviews the rapid development of multiphase flow technology, demonstrates the latest development of the technology, and showcase the very latest applications. It provides readers with comprehensive updated reference information covering theory, modelling and numerical methods, design and measurement, and new applications in multiphase flow systems. The Handbook consists of three parts or volumes: 1. Theory: describes the fundamentals including the concepts and definitions of multiphase flows. Classifications of multiphase flows. Basic understanding of different length scales involved – micro/nano, meso and macro. Treatment of such flows by different solution frameworks. 2. Modelling and Measurement: covers both classical and state-of the-art measurement and modelling approaches to resolve different classifications of multiphase flows. 3. Applications: highlights the very latest applications of measurement and modelling approaches in tackling different classification of multiphase flows in a variety of natural, biological and industrial systems and different length scales.

Abstrak :
This book contains a collection of the main contributions from the first five workshops held by Ercoftac Special Interest Group on Synthetic Turbulence Models (SIG42. It is intended as an illustration of the sig’s activities and of the latest developments in the field. This volume investigates the use of Kinematic Simulation (KS) and other synthetic turbulence models for the particular application to environmental flows. This volume offers the best syntheses on the research status in KS, which is widely used in various domains, including Lagrangian aspects in turbulence mixing/stirring, particle dispersion/clustering, and last but not least, aeroacoustics.

Abstrak :
Pengurangan tahanan pada kapal dengan metode air lubrication menggunakan microbubble telah dimulai pada akhir abad ke 19. Bagaimanapun, aplikasinya pada industry terhalang karena penghematan daya bersih hanya berkisar 0-5 persen akibat energi yang dibutuhkan oleh kompresor udara untuk menginjeksi udara ke lunas kapal. Peranti baru bernama Winged Air Induction Pipe (WAIP) menggunakan tekanan negatif yang dihasilkan dari hidrofoil bersudut untuk menghisap udara bertekanan atmosfir ke dalam air hingga menghasilkan gelembung tanpa dibutuhkannya kompresor. Dimensi dari chord length pada hidrofoil mempengaruhi pengurangan tahanan yang terjadi. Pendekatan Computational Fluid Dynamics (CFD) dengan model volume of fluid dan permodelan turbulensi k-ω SST pada kondisi batas 2 dimensi digunakan untuk mengobservasi bagaimana variabel ini mempengaruhi hasilnya. Konfigurasi dari chord length pada hidrofoil untuk memberikan efisiensi maksimal pada kapal akan dibahas. Dalam rentang optimal, pengurangan tahanan dapat mencapai 9 persen. ...... Drag reduction on ship with air lubrication method using microbubble has been started on late 19th century. However, the application in industry obstructed because the net power saving only 0-5 persen consequences of the energy needed by air compressor to inject the air to the keel of the ship. New device named Winged Air Induction Pipe (WAIP) use the negative pressure produced by angled hydrofoil to suck atmospheric air into the water generating bubble without compressor needed. Dimention of the hydrofoil chord length influenced the drag reduction occurred. Computational Fluid Dynamics (CFD) approach with volume of fluid model and SST k-ω turbulence closure model on 2D boundary condition used to observe how this variable affecting the result. Configuration of hydrofoil chord length to give the maximum efficiency to the ship is discussed. On the optimum range, drag reduction can reach 9 persen.

Abstrak :
Penggunaan mikofluida dapat meningkatkan proses pembentukan droplet sekaligus mengurangi konsumsi energi. Dalam penelitian ini, sistem mikroreaktor dengan sambungan T ganda dan reaktor saluran pipa mikro sepanjang 830 mm dianalisis. Aliran itu terdiri dari stirena dan air. Konsentrasi air dalam emulsi dan laju aliran air dan stirena dievaluasi. Tetesan diamati pada rasio laju aliran stirena terhadap air mulai dari 1:5 hingga 1:50. Simulasi di persimpangan T ganda dilakukan dengan aliran laminar dan model Volume Of Fluids dipilih untuk interaksi fase. Percobaan dengan sembilan laju aliran stirena dan air dilakukan. Sistem optik sederhana digunakan untuk pengamatan in-line dari tetesan yang terbentuk di mikroreaktor. Untuk flow ratio 1:5, tidak terjadi pembentukan drop. Untuk laju lainnya, ukuran tetesan diamati berdiameter dari 8 hingga 41 μm. Tetesan bergerak sepanjang reaktor mempertahankan bentuk dan ukuran. Hal tersebut menunjukkan bahwa sistem reaksi mikro cocok untuk mengembangkan sistem yang membutuhkan stabilitas, seperti polimerisasi emulsi. Perbandingan antara model dan hasil eksperimen menunjukkan bahwa ini cukup terwakili oleh model. ......The creation of droplets may be enhanced while using less energy by using microfluidics. The current study examined a microreactor system with a double T junction and an 830 mm-long circular microchannel reactor. Water and styrene made up the stream. Water and styrene flow rates as well as the volume percent of water in the emulsion were assessed. Styrene to water flow rate ratios between 1:5 and 1:50 produced droplets. The Volume Of Fluids model was utilized for the phase interactions during the simulations of the double T junction, which were conducted with laminar flow. Calculations were made for nine different styrene and water flow rates. Droplets created in the microreactor were seen in-line using a data-generated point and line. There were no drops formed at a flow ratio of 1:5. Droplets between 8 and 41 m were seen at the other rates. While moving through the reactor, the droplets kept their size and form. This proves that the micro reaction system is appropriate for creating stable systems, including emulsion polymerizations. The comparison of model and experimental data revealed that the model well captured these findings.

Abstrak :
Pengukuran laju aliran multifase merupakan hal yang krusial dalam industri minyak dan gas. Pengukuran laju aliran menjadi sangat penting untuk optimalisasi produksi dan flow assurance sistem produksi minyak. Multiphase Flow meter (MPFM) merupakan alat yang digunakan untuk melakukan pengukuran laju aliran multifase sehingga memiliki keunggulan dapat melakukan pengukuran dan mendapatkan hasil laju aliran dalam waktu singkat. Semakin berkembangnya kecerdasan buatan, pengukuran dapat juga dilakukan secara virtual. Virtual Flow Metering (VFM) merupakan salah satu cara pengukuran laju aliran multifase dengan menggunakan data sensor yang ada di ESP, dan pengukuran MPFM. Pada penelitian ini telah dirancang model machine learning untuk estimasi laju aliran menggunakan metode super learner dengan base learner XGBoost, AdaBoost, Bagging, Random Forest, dan Extra Trees. Estimasi laju aliran yang didapat dievaluasi dan divalidasi dengan menggunakan MAE, MAPE, R squared, dan cumulative deviation plot. Berdasarkan hasil evaluasi tersebut, model super learner menunjukkan hasil yang lebih baik dibandingkan model base learner yang digunakan, dengan hasil MAE 0,63, MAPE 1,60%, R squared 97,43%, dan maksimal deviasi 12,5%. ......Multiphase flow rate measurement is crucial in the oil and gas industry. Flow rate measurement is very important for optimization of production and flow assurance of oil production systems. Multiphase Flow meter (MPFM) is a tool used to measure multiphase flow rates so that it has the advantage of being able to take measurements and get flow rate results in a short time. As artificial intelligence develops, measurement can also be done virtually. Virtual Flow Metering (VFM) is a way of measuring multiphase flow rates using sensor data in the ESP and MPFM measurements. In this study, a machine learning model for flow rate estimation has been designed using the super learner method with the base learner XGBoost, AdaBoost, Bagging, Random Forest, and Extra Trees. The flow rate estimates obtained were evaluated and validated using the MAE, MAPE, R squared, and cumulative deviation plots. Based on the results of this evaluation, the super learner model shows better results than the base learner model used, with MAE 0.63, MAPE 1.60%, R squared 97.43%, and a maximum deviation of 12.5%.

Abstrak :
Multiphase flows are typically described assuming that the different phases are separated by a sharp interface, with appropriate boundary conditions. This approach breaks down whenever the lengthscale of the phenomenon that is being studied is comparable with the real interface thickness, as it happens, for example, in the coalescence and breakup of bubbles and drops, the wetting and dewetting of solid surfaces and, in general, im micro-devices. The diffuse interface model resolves these probems by assuming that all quantities can vary continuously, so that interfaces have a non-zero thickness. This book review the theory and describe some relevant applications of the diffuse interface model for one-component, two-phase fluids and for liquid binary mixtures, to model multiphase flows in confined geometries.

Abstrak :
Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its fourth extended edition the successful monograph package “Multiphase flow daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the local volume and time averaging is used to derive a complete set of conservation equations for three fluids each of them having multi components as constituents. Large parts of the book are devoted on the design of successful numerical methods for solving the obtained system of partial differential equations. Finally the analysis is repeated for boundary fitted curvilinear coordinate systems designing methods applicable for interconnected multi-blocks.

Abstrak :
Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase flow daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present second volume the methods for describing the mechanical interactions in multiphase dynamics are provided.