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Abstrak :
This book treats the numerical analysis of finite element computational fluid dynamics. Assuming minimal background, the text covers finite element methods; the derivation, behavior, analysis, and numerical analysis of Navier-tokes equations; and turbulence and turbulence models used in simulations. Each chapter on theory is followed by a numerical analysis chapter that expands on the theory. The chapters contain numerous exercises.

Abstrak :
The flow behavior of fluids such as molten plastics, biological fluids, and paints is much more varied and complex than that of traditional Newtonian fluids. The role of numerical simulation in the study of such flows has increased tremendously over the past fifteen years, and the phenomena and numerical difficulties in complex flows have led to new and challenging mathematical questions. Studying such flows presents a host of problems, as well as opportunities for mathematical analysis, including questions of asymptotics, qualitative dynamics, and adequacy of numerical methods. Mathematical Analysis of Viscoelastic Flows presents an overview of mathematical problems, methods, and results relating to research on viscoelastic flows. This monograph is based on a series of lectures presented at the 1999 NSF-CBMS Regional Research Conference on Mathematical Analysis of Viscoelastic Flows. It begins with an introduction to phenomena observed in viscoelastic flows, the formulation of mathematical equations to model such flows, and the behavior of various models in simple flows. It also discusses the asymptotics of the high Weissenberg limit, the analysis of flow instabilities, the equations of viscoelastic flows, jets and filaments and their breakup, as well as several other topics.

Abstrak :
This paper presents a set of numerical simulations of different 2D boundary-value problems in order to validate a “smoothed-particle hydrodynamics”-“arbitrary Lagrangian-Eulerian” (SPH-ALE) code. This code is intended to be used to study, among other things, the problem of piping erosion in dams and dikes. The case of viscous fluid flows around a fixed cylinder was first examined. Different Reynolds numbers and different shapes for the cylinder were considered. The drag coefficient, lift coefficient, pressure coefficient, and Strouhal number were compared with previous studies from the literature. Next, a validation of the case of a Poiseuille flow between smooth pipe walls with Re = 100 was provided. The friction coefficient was computed and compared to existing analytical solutions.

Abstrak :
ABSTRAK
Indonesia telah meresmikan peraturan gempa terbaru bernama SNI 1726-2019. Pembuatan peraturan gempa terbaru didasari oleh adanya penemuan sesar aktif, data sumber gempa dan pembaruan lainya dari teknologi gempa. SNI 1726-2019 diadopsi dari ASCE 7-16 yang telah menggunakan konsep uniform risk dengan probabilitas kegagalan 1% dari 50 tahun umur bangunan dan performa target collapse prevention untuk periode ulang gempa 2475 tahunan dimana pada peraturan SNI 1726-2002 konsep yang digunakan adalah uniform hazard dan performa target life safety untuk periode ulang gempa 500 tahunan. Dengan adanya perbedaan tersebut termasuk juga perbedaan metode perhitungan gaya gempa, gaya gempa dasar yang dihasilkan sesuai SNI 1726-2019 untuk bangunan 14 dan 21 lantai dengan sistem struktur berupa dual system kombinasi SRPMK dengan dinding geser khusus adalah sebesar 1.65 dan 1,9 kali gaya gempa dasar yang dihasilkan pada SNI 1726-2002. Evaluasi performa bangunan ini menggunakan metode disain berbasis kinerja berupa analisa nonlinear riwayat waktu dengan 11 pasang rekaman gempa sesuai ASCE 41-17. Hasil analisa dari kedua bangunan eksisting tersebut menunjukan bahwa kedua bangunan tersebut tidak dapat mencapai performa target collapse prevention untuk BSE-2N. Perkuatan dilakukan dengan menggunakan viscous wall damper (VWD) untuk mencapai performa target dan meminimalisir gangguan dari aktivitas di dalam bangunan. 10 variasi model dianalisa untuk mengetahui pengaruh dari VWD terhadap performa global dan komponen. Variasi model dilakukan berdasarkan parameter koefisien redaman (c) dari VWD dan jumlah VWD pada setiap jenis bangunan. Hasil analisa menunjukan bahwa penggunaan VWD akan meningkatkan performa global bangunan terkait simpangan antar lantai dan simpangan antar lantai residual. Dalam tingkat komponen, VWD akan meningkatkan performa komponen balok dengan menggeser performa komponen ke tingkat yang lebih baik. Berbeda pada kebanyakan komponen, untuk komponen yang dipasangkan VWD ataupun berlokasi satu garis gaya dengan VWD harus diberikan perhatian khusus karena VWD akan meningkatkan kebutuhan gaya dalam dan deformasi dari komponen tersebut sehingga membutuhkan perkuatan secara lokal.

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ABSTRACT
Considering the latest finding on active faults, updates on the seismic database, and other refinements, Indonesia released latest seismic code namely SNI-1726-2019. SNI-1726-2019 is adopted from the ASCE-7-16 which has the uniform risk concept of 1% probability of collapse in 50 years and target performance of collapse prevention for the 2475 years return period earthquake. Different to that, SNI-1726-2002 has uniform hazard concept and target performance of Life Safety for the 500 years return period earthquake. Accumulating those differences and adding others differences in seismic calculation procedure, for 14-story and 21-story building, dual system of SMF and special RC Shear Wall, the latest code results seismic demand of 1.65 and 1.9 times higher than that in the 2002 code. To evaluate its performance designed originally with strength based design in accordance to SNI-1726-2002, the Performance Based Design (PBD) using Non Linear Time History Analysis (NLTHA) with 11 pairs of matched ground motions was carried out in accordance to ASCE-41-17. The PBD result of the two existing buildings show that both performances don't meet the target performance. To achieve target performance of Collapse Prevention for BSE-2N and to minimize building operation disturbance, Viscous Wall Damper (VWD) is introduced for retrofit system. 10 variations in terms of VWD damping coefficient (c) and amount of VWD are modeled to understand the effect of VWD to its global and component performances. The analysis results show that installing VWD may increase the global performance in terms of interstory drift(IDR) and residual interstory drift. In the component level, this retrofit can increase the performance of the beam component by shifting its performance to better level. But for some component, attached by the VWD or located in one grid with VWD, shall be looked closely and may need local strengthening due to the increase of force and deformation demand.

Abstrak :
Masalah polusi saat ini menjadi fokus utama dalam terjadinya global warming di dunia. Salah satu penyumbang utama dari polusi itu ada pada industri perkapalan. Penggunaan bahan bakar minyak yang masif oleh kapal diseluruh dunia, terutama kontainer dan tanker yang menyumbang 40% total polusi dunia. Salah satu cara untuk mengatasi masalah ini adalah peningkatan efisiensi bahan bakar dengan menggunakan metode lubrikasi udara untuk meningkatkan drag reduction dari kapal tersebut. Pada skripsi ini digunakan metode Winged Air Induction Pipe untuk melubrikasi bagian bawah kapal. Winged Air Induction Pipe adalah sebuah alat yang menggunakan foil pada bagian bottom kapal untuk menghasilkan bubble dengan memproduksi udara rendah pada bagian atas foil tersebut. Udara yang terhisap ini nantinya akan masuk melalui pipa yang selanjutnya akan terperangkap pada aliran dan menjadi bubble. Bubble inilah yang nantinya akan melubrikasi plat kapal dan meningkatkan drag reduction pada kapal tersebut. Pada penelitian sebelumnya telah dilakukan metode yang sama namun pembahasan terkait variasi konfigurasi chord length foil dan bagaimana pengaruh viscous resistance pada foil terhadap pembentukan bubble belum lah dibahas. Penelitian ini dilakukan secara numerikal dengan menggunakan ANSYS CFD-Fluent dengan menggunakan metode k-w (Shear Stress Transport). Dengan membandingkanya dengan penelitian secara eksperimental yang dilakukan sebelumnya didapat tingkat error sebesar 1,49%. Selain itu digunakan pula NACA 653-618 yang sama yang digunakan oleh penelitain sebelumnya dengan tambahan variasi panjang chord length. Pada akhir penelitian ini didapatkan bahwa terdapat tendensi dari viscous resistance terhadap variasi konfigurasi yang mempengaruhi besar daya yang disimpan. Pada akhirnya daya yang disimpan oleh alat hingga 6 %. ...... Pollution is a main focus in the status quo of global warming. One of those main contributors is the shipping industry. Massive usage in fuel oil by the ship around the world, especially the container and tanker ship produce more than 40% of total world pollution. One of those methods to solve this is problem is increasing the efficiency of ship using air lubrication method by increasing the drag reduction of the ship. In this research, we used the device called as Winged Air Induction Pipe (WAIP) to lubricate the bottom of the ship. This device used foil to create bubbles by making low pressure area in the upper area of the foil which will suck the atmospheric air through the pipe and trap those air inside the flow which will became bubbles. In the previous research the same method has been done, but the explanation about how the various configuration of chord length and the effect of viscous resistance will affect the creation of the bubbles were not explained yet. In this research, we used numerical simulation by using ANSYS CFD-Fluent with k-w SST (Shear Stress Transport) method. At the end the error occured only 1,49 % compared with experimental research done by previous studies. This research also used the same NACA 653-618 which has been used by previous study within the addition of variation of the chord length of the foil. At the end of the research, there is a tendency between viscous resistance and net power saving by the device, which is at 6% of total power saving.

Abstrak :
Fluida Carreau non-Newtonian, yang menunjukkan sifat penipisan geser, memberikan pendekatan yang lebih realistis untuk mensimulasikan fenomena penjarian kental dibandingkan dengan fluida Newtonian. Sifat penipisan geser dari cairan non-Newtonian memungkinkan cairan yang disuntikkan untuk menyerang daerah dengan radius lebih kecil dengan lebih mudah, yang dapat mempengaruhi proses penjarian kental dan mendorong pembentukan jari. Sebaliknya, simulasi Pinilla et al. (2021) yang memanfaatkan fluida Newton tidak memberikan gambaran yang lengkap dan detail tentang bagaimana jari kental dapat terjadi dalam situasi kehidupan nyata. Simulasi penulis, yang menggabungkan sifat fluida non-Newtonian, menawarkan gambaran fenomena viscous fingering yang lebih realistis, mirip dengan eksperimen yang dilakukan oleh Doorwar dan Mohanty (2015), di mana CFD dapat mensimulasikan VF dalam 3D dengan meniru fitur umum dari fenomena ini. , seperti kelahiran jari, penggabungan atau penggabungan, pemblokiran, pemisahan ujung, dan perluasan jari utama. Porositas dapat memainkan peran penting dalam mempengaruhi kemunculan dan pertumbuhan jari-jari kental pada media berpori, mempengaruhi faktor-faktor seperti penekanan jari dan interaksi dengan rasio viskositas. Dalam hal ini, nilai porositas terendah yaitu 0,29 merupakan simulasi terbaik karena membentuk semua parameter yang dibutuhkan lebih baik dibandingkan dua nilai porositas lainnya. Dengan memvariasikan nilai porositas, kita dapat mengetahui nilai porositas mana yang paling sesuai dengan simulasi kita yang dapat dengan mudah membuat parameter jari kental yang diperlukan, seperti pemisahan, perpindahan, dan penggabungan. ......Non-Newtonian Carreau fluids, which exhibit shear-thinning properties, provide a more realistic approach to simulating viscous fingering phenomena compared to Newtonian fluids. The shear-thinning property of non-Newtonian fluids allows the injected fluid to invade smaller-radius regions more easily, which can affect the viscous fingering process and promote the formation of fingers. In contrast, Pinilla et al.'s (2021) simulation, which utilizes Newtonian fluids, does not provide a complete and detailed picture of how viscous fingers can occur in real-life situations. The author's simulation, which incorporates non-Newtonian fluid traits, offers a more realistic portrayal of the viscous fingering phenomenon, similar to the experiments conducted by Doorwar and Mohanty (2015), where the CFD can simulate VF in 3D emulating common features of this phenomenon, such as finger birth, merge or coalesce, blocking, tip-splitting, and expansion of main fingers. Porosity can play a significant role in influencing the occurrence and growth of viscous fingers in porous media, affecting factors such as finger suppression and the interplay with viscosity ratios. In this case, the lowest value of porosity, which is 0.29, serves as the best simulation as it forms all the needed parameters better than the other two values of porosity. By varying the value of porosity, we can learn which value of porosity serves our simulation the best that could easily create the needed parameters of the viscous finger, such as the splitting, displacement, and coalescence.

Abstrak :
Interfacial fluid mechanics: a mathematical modeling approach provides an introduction to mathematical models of viscous flow used in rapidly developing fields of microfluidics and microscale heat transfer. The basic physical effects are first introduced in the context of simple configurations and their relative importance in typical microscale applications is discussed. Then, several configurations of importance to microfluidics, most notably thin films/droplets on substrates and confined bubbles, are discussed in detail. Topics from current research on electrokinetic phenomena, liquid flow near structured solid surfaces,evaporation/condensation, and surfactant phenomena are discussed in the later chapters.

Abstrak :
This book describes recently developed research methods used to study complex problems in fluid engineering, especially optical flow measurement, flow visualization and numerical methods. It includes a wealth of diagrams and images, and the content is presented in a step-by-step manner from beginning to end, helping readers grasp the central points of the book. The book also presents a number of practical cases, illustrating how the research methods covered can be concretely implemented. Lastly, the book offers a valuable point of departure for pursuing further research.