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"High speed catamaran and multihull high speed marine vessel have become very popular in the last two decades. The catamaran has become the vessel of choice for the majority of high speed ferry operators worldwide. There have been significant advances in structural materials, and structural design has been combined with higher power density and fuel efficient engines to deliver ferries of increasing size. The multihull has proven itself to be a suitable configuration for active power projection across oceans as well as for coastal patrol and protection, operating at high speedd for insertion or retrieval with a low energy capability. At present there is no easily accessible material covering the combination of hydrodynamics, aerodynamics, and design issues including structures, powering and propulsion for these vehicles. Coverage in High Speed Catamarans and Multihulls includes an introduction to the history, evolution, and development of catamarans, followed by a theoretical calculation of wave resistance in shallow and deep water, as well as the drag components of the multihull. A discussion of vessel concept design describing design characteristics, empirical regression for determination of principal dimensions in preliminary design, general arrangement, and methods is also included. The book concludes with a discussion of experimental future vehicles currently in development including the small waterplane twin hull vessels, wave piercing catamarans, planing catamarans, tunnel planing catamarans and other multihull vessels."

""Drag Reduction of Complex Mixtures discusses the concept of drag reduction phenomena in complex mixtures in internal and external flows that are shown experimentally by dividing flow patterns into three categories. The book is intended to support further experiments or analysis in drag reduction. As accurately modeling flow behavior with drag reduction is always complex, and since drag reducing additives or solid particles are mixed in fluids, this book covers these complex phenomena in a concise, but comprehensive manner.Comprehensively addresses a range of drag reduction themes involving different kinds of complex mixtures. Provides data to support further experimentation and computer modeling of drag in complex flow. Includes an introduction to the nature and characteristics of different kinds of complex mixtures"

"This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the 0.01 M DEA solution flows in the shell side of membrane contactors. Experimental results show that the mass transfer coefficients and fluxes of CO2 increase with an increase in both water and DEA solution flow rates. Increasing the amount of fibers in the contactors will decrease the mass transfer and fluxes at the same DEA solution flow rate. Mass transfer coefficients and CO2 fluxes using DEA solution can achieve 28,000 and 7.6 million times greater than using water as solvent, respectively. Hydrodynamics studies show that the liquid pressure drops in the contactors increase with increasing liquid flow rate and number of fibers in the contactors. The friction between water and the fibers in the contactor was more pronounced at lower velocities, and therefore, the value of the friction factor is also higher at lower velocities."

"Sebuah peranti baru untuk air lubrication yang disebut Winged Air Induction Pipe WAIP telah dipelajari pada penelitian kali ini. Peranti tersebut, yang memiliki hydrofoil dengan suatu sudut tertentu, menggunakan daerah bertekanan rendah yang dihasilkan pada bagian atas dari hydrofoil saat kapal bergerak terhadap fluida cair disekitarnya. Tekanan rendah yang dihasilkan mendorong udara atmosferis ke dalam air pada kecepatan tertentu dimana tekanan yang dihasilkan adalah negatif dibandingkan dari tekanan atmosferis. Pendekatan computational fluid dynamics dilakukan untuk mempelajari pengaruh dari clearance dari hydrofoil pada Winged Air Induction Pipe dalam pengurangan tahanan yang dialami oleh pelat dimana peranti WAIP dipasangkan. Model multifase volume of fluid dan model turbulensi k-w SST shear stress transport digunakan di dalam simulasi numerik. Simulasi dilakukan dengan konfigurasi clearance dari hydrofoil terhadap botton plate model dan angle of attack yang berbeda. Pengaruh dari parameter tersebut terhadap pengurangan tahanan dijelaskan pada penelitian ini. Pengurangan tahanan diperoleh hingga 10 dibandingkan konfigurasi tanpa WAIP.

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A new device for air lubrication called Winged Air Induction Pipe WAIP is studied in the present work. The device, which consists of angled hydrofoil uses the low pressure region produced above the hydrofoil as ship moves forward. The low pressure drives the atmospheric air into the water in certain velocities which the pressure is negative compare to atmospheric pressure. A computational fluid dynamics approach is presented to study the effect of hydrofoil clearance of Winged Air Induction Pipe in drag reduction experienced by the plate which WAIP attached. The well known 39 volume of fluid 39 model and k w SST shear stress transport turbulence closure model have been used in the numerical simulation. The numerical simulation is carried out with different configuration of hydrofoil clearance and angle of attack. Effects of these parameters on total drag force and drag reduction are reported. The reduction of drag force is found to increase to about 10 compared to bare plate configuration."

"ABSTRAKPenelitian ini bertujuan untuk mempelajari hidrodinamika dalam reaksi transesterifikasi pada reaktor batch berpengaduk. Parameter hidrodinamika yang didapatkan kemudian digunakan sebagai kriteria kesamaan scale-up. Penelitian ini menerapkan metode computational fluid dynamics CFD dalam studi hidrodinamika fluida pada reaksi transesterifikasi di reaktor batch berpengaduk. Pemodelan reaktor batch berpengaduk untuk reaksi transesterifikasi dikomputasi dengan menggunakan COMSOL Multiphysics. Nilai kecepatan fluida, pola aliran, distribusi tekanan, fraksi volume, kerapatan jumlah partikel, kecepatan relatif, shear rate, diameter butir fasa terdispersi, serta luas bidang antarfasa spesifik a didapatkan. Nilai a pada reaktor skala laboratorium didapatkan sebesar 45120 1/m dan dijadikan sebagai parameter kesamaan scale-up. Dengan ukuran reaktor skala besar sebesar 1,309 m3, diperlukan kondisi operasi kecepatan putar impeller sebesar 285,16 rpm untuk mendapatkan nilai luas bidang antarfasa spesifik a yang sama dengan kriteria kesamaan scale-up.

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ABSTRACTThe purposes of this research is to study the hydrodynamics of transesterification reaction in stirred batch reactor. The obtained hydrodynamics then used as scale up similariy criterion. This research used computational fluid dynamics CFD as method to study the transesterification in stirred batch reactor. By using COMSOL Multiphysics, the modeled transport equation is computed. The hydrodynamics parameters observed are mean velocity field, flow pattern, pressure distribution, volume fraction of dispersed phase, number density of droplet, dispersed phase relative velocity, shear rate, average diameter of dispersed phase droplet, and interfacial area per volume. The simulation results show that the specific interfacial surface area a on laboratorium scale reactor is 45120 1 m and used as scale up similarity criterion. For 1,31 m3 large scale reactor, the rotational speed condition to obtain specific interfacial surface area a is 285,16 rpm to match the scale up similarity criterion."

"Smoothed Particle Hydrodynamics (SPH) awalnya dibuat untuk mensimulasikan fenomena non-aksisimetris dalam astrofisika. Namun, metode ini masih memiliki beberapa kelemahan, yaitu biaya komputasi yang tinggi yang diperlukan untuk memodelkan nilai dengan resolusi tinggi dan masalah dengan kondisi batas. Penelitian ini bertujuan untuk menjawab apakah pemodelan SPH dengan fokus pada aliran kontinu dapat menghasilkan nilai yang akurat secara kuantitatif dengan biaya komputasi yang rendah. Penelitian ini akan menggabungkan algoritma dan pengkodean pada program utama sungai berkelok-kelok dan algoritma aliran kontinu dengan tujuan untuk mendapatkan hasil yang akurat secara kuantitatif pada interaksi fluida padat dengan aliran kontinu pada saluran berkelok-kelok menggunakan metode SPH. Penelitian ini menggunakan bahasa pemrograman Fortran untuk pemodelan metode numerik SPH (Smoothed Particle Hydrodynamics), model dilakukan dalam bentuk saluran terbuka berkelok-kelok berbentuk U secara 3D, dimana dinding saluran merupakan dinding yang tidak dapat ditembus dan menggunakan saluran kontinu. mengalir dengan jumlah partikel yang terbatas.

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Smoothed Particle Hydrodynamics (SPH) was originally created to simulate nonaxisymmetric phenomenon in astrophysics. However, this method still has several shortcomings, namely the high computational cost required to model values with high resolution and problems with boundary conditions. This research aims to answer if SPH modeling with a focus on continuous flow can produce quantifiably accurate values with low computational cost. This research will combine algorithms and coding in the main program of meandering river and continuous flow algorithm with the aim of obtaining quantitatively accurate results on solid fluid interactions with continuous flow on a meandering channel using the SPH method. This study uses the Fortran programming language for modeling the SPH (Smoothed Particle Hydrodynamics) numerical method, the model is conducted in the form of a U-shaped meandering open channel in 3D, where the channel walls are non-penetrable wall and uses a continuous flow with a limited number of particles."

"Penambahan larutan aditif pada aliran di dalam pipa dapat mengurangi hambatan gesek. Pada penelitian ini fluida yang dicampur dengan Nata de Coco dialirkan dalam pipa bulat D=3mm dan pipa spiral segi lima P/Di=10.8 mm. Perbedaan tekanan yang terjadi pada fluida kerja dapat dilihat dari kedua pressure tap yang dipasang di pipa dengan jarak 900 mm. Perubahan friction factor diprediksi akan berpengaruh terhadap pengurangan hambatan. Serat ini akan berpengaruh terhadap pengurangan hambatan baik di pipa bulat maupun pipa spiral segi lima. Dalam penelitian ini juga dilihat hubungan antara mekanisme pengurangan hambatan dengan degradasi dari fluida kerja. Berdasarkan data yang didapat dari penelitian ini Nata de Coco dengan konsentrasi 60 ppm yang dialirkan pada pipa spiral segi lima Pi/D=10.8 dapat menghasilkan drag reduction sebesar 26.27%. Nata de Coco juga dapat tahan terhadap degradasi, setelah dialirkan selama 6 jam drag reduction hanya berkurang sebesar 2.86%.

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Addition of additive solutions to the flow in the pipe can reduce friction loss. In this study the fluids mixed with Nata de Coco flowed in round pipe D = 3mm and pentagon spiral pipe P / Di = 10.8 mm. The difference in pressure that occurs in the working fluids can be seen from both pressure taps installed in the pipe with a distance of 900 mm. Changes in friction factors are predicted to have an effect on drag reduction. This biopolymer will affect the drag reduction both pentagon spiral pipes and round pipes. This biopolymer will affect drag reduction in both pentagon spiral pipes and round pipes.

In this study also seen the relationship between drag reduction and degradation of fluids. Based on the data obtained from this study, the Nata de Coco with a concentration of 60 ppm flowed in the pentagon spiral pipe Pi/D = 10.8 can produce 26.27% drag reduction. Nata de Coco also resistant to degradation, after being flowed for 6 hours drag reduction only decreased by 2.86%."

"The long-awaited revision of a classic! This new edition presents a balanced introduction to transport phenomena, which is the foundation of its long-standing success. Topics include mass transport, momentum transport and energy transport, which are presented at three different scales: molecular, microscopic and macroscopic."

"This collection is dedicated to the 70th jubilee of Yu. N. Savchenko, and presents experimental, theoretical, and numerical investigations written by an international group of well-known authors. The contributions solve very important problems of the high-speed hydrodynamics,such as supersonic motion in water, drag diminishing, dynamics and stability of supercavitating vehicles, water entry and hydrodynamic performances of hydrofoils, ventilated cavities after a disc and under the ship bottom. "