COMPARATIVE PARAMETRIC ANALYSIS OF GAS FLOW IN THREE DIFFERENT DESIGNS OF IN-LINE SCRUBBER BOTTOM INLET

In this study, gas flow fields were simulated using ANSYS 2020R2, Fluid Flow Fluent computational fluids dynamic (CFD) software based on the continuity, velocity, temperature, energy and k - e turbulence. The overall objective of the study is to compare the velocity maps inside the wet scrubber system for three different In-Line scrubber bottom inlet designs. Also, the behavior of the temperature of the mixture inside the scrubber is studied according to the number of nozzles provided by each system from those proposed for study. The numerical simulation using CFD is an effective method to study the flow characteristics of a counter-flow wet scrubber system and the most efficient wet scrubber model is the one with several. The results show that the residuals have a very good job of converging at minimum flow contours and vectors at the inlet across the scrubbing chamber and outlet shows a distributed flow. The speed of water droplets sprayed by the nozzles during mixing with waste gas in the scrubber chamber is double at model with 52 nozzles compared to the first model, equipped with only 13 nozzles. The velocity of clean gases discharged to the ship’s hull shows increases of over 100% of the values, with the increase of the number of nozzles. Spray nozzles improve mixing between the scrubbing liquid and waste gas, by injecting liquid through nozzles to create a fine droplet spray pattern. In this study it can be seen how the number of nozzles influences the quality of the mixture between the scrubbing liquid and waste gas.

Pengaruh Jumlah Sudu 8, 12, 16 dan 20 terhadap Performa Hidro-Turbin Cross-Flow dengan sudut 15° Menggunakan Metode Computational Fluids Dynamics

<p>Energi listrik merupakan kebutuhan primer dalam kehidupan sehari-hari. Perkembangan teknologi mengakibatkan meningkatnya kebutuhan energi listrik setiap tahunnya. Energi baru terbarukan memasok kebutuhan energi listrik nasional sebesar 14%. Di sisi lain, pemerintah mengharapkan komposisi energi baru terbarukan sebesar 23% hingga 31% pada tahun 2050. Hal ini menunjukan bahwa energi baru terbarukan masih memiliki gap yang cukup tinggi. Penelitian ini merupakan salah satu upaya dalam pengembangan energi baru terbarukan, terutama pada pembangkit listrik mikro-pico hidro. Penelitian ini dilakukan menggunakan metode <em>Computational Fluid Dynamics</em> menggunakan Aplikasi Ansys dengan CFX <em>Solver</em>. Penelitian dilakukan untuk mengetahui pengaruh jumlah sudu pada hidro-turbin <em>cross-flow</em> terhadap performa <em>Coefficient of Power</em>. Peneltian dilakukan pada rotor dengan dimensi diameter 80 mm, panjang 130 mm dan sudut sudu 15°. Variasi jumlah sudu dilakukan pada jumlah sudu 8, 12, 16, dan 20. Simulasi dilakukan pada <em>steady state,</em> dan menggunakan tipe turbulen <em>Shear Stress Transport</em>. Turbin <em>cross-flow</em> beroperasi pada kecepatan air 3m/s dengan kecepatan sudut pada interval 50 sampai 350 RPM. Hasil menunjukan <em>Coefficient of Power Maximum</em> yang dihasilkan untuk sudu 8,12, 16 dan 20 adalah 10,8%; 14,1%; 16,8% dan 20,1%. Dari hasil tersebut menunjukan performa maksimal dihasilkan oleh hidro-turbin tipe <em>cross-flow</em> dengan jumlah sudu rotor 20.</p>

Numerical Investigation of Dropwise Condensation on Smooth Plates with Different Wettability

Condensers are used in various energy-intensive processing industries. Improving their efficiency plays a crucial role in the optimization of energy consumption. Dropwise Condensation is a highly attractive form of heat transfer. This project investigates the effects of different wettability characteristics in drop-wise condensation on smooth plates. It involves a Volume of Fluid (VOF) based Computational Fluids Dynamics (CFD) model to carry out the simulations in Open FOAM on smooth plates various wettability’s. Different parameters such as receding angle, advancing angle, and various radii of droplets have been used for investigation. A base case with droplets’ radius of 12.5μm, receding angle, and advancing angles of (34°, 90°) was used. Three sets of simulations were performed. In Set 1, the angles were (34°, 90°). The radius of the first droplet was kept constant at 12.5μm and the radius of the second droplet changes 1:4 progressively. In Set 2, the angles are changed to (154°, 162°), and the radius of the second droplet changes in the same manner above. In Set 3, the angles were kept at (107°, 117°). The radius changes as above. In some cases, the droplets merge and condense. In others, the momentum created by merging of the droplets creates repeated oscillation or even a lift-off, from the cooling plate.

A Review of CFD Analysis of Heat Exchanger for Laminar Flow

Helical coil heat exchangers, due to their maturity, are widely used in industrial applications such as the chemical and food industry, power generation, electronics, environmental technology, manufacturing industry, air conditioning, waste heat recovery, etc. on straight and cup heat exchangers. With its compact structure, larger heat transfer area and higher heat transfer capacity, etc., the twisted tap and classification of improvement techniques are presented in this paper. To present the dynamics, application, and advantages of CFD for computational fluids presented in this paper.

Analysis of the purge time values for pressurized enclosure using a parameterized CFD model

The use of computerized simulations offers definite advantages in understanding phenomena and analysing parameters that have influence during a complex process, more can provide on the basis of scenarios valuable information on the effects for physical processes analysed. Thus, in this paper, using mathematical models and numerical solutions based on physical principles and functions with assumed accuracy are analyse, using CFD (Computational fluids dynamics), the values of purge time for pressurized enclosure, resulting in the action of post-processing of construction for graphs and colour icons, in order to render images as representative possible both for the design phase of the equipment with protection type pressurization “p” and for their evaluation for certification. Determining the values of purging time by using computer simulations is particularly important for avoiding catastrophic events caused by explosions that can lead to human casualties, significant material losses or have significant environmental consequences.

Bioink Temperature Influence on Shear Stress, Pressure and Velocity Using Computational Simulation

Bioinks are usually cell-laden hydrogels widely studied in bioprinting performing experimental tests to tune their rheological properties, thus increasing research time and development costs. Computational Fluids Dynamics (CFD) is a powerful tool that can minimize iterations and costs simulating the material behavior using parametric changes in rheological properties under testing. Additionally, most bioinks have specific functionalities and their properties might widely change with temperature. Therefore, commercial bioinks are an excellent way to standardize bioprinting process, but they are not analyzed in detail. Therefore, the objective of this work is to study how three temperatures of the Cellink Bioink influence shear stress pressure and velocity through computational simulation. A comparison of three conical nozzles (20, 22, and 25G) for each temperature has been performed. The results show that shear stress, pressure, and velocity vary in negligible ranges for all combinations. Although these ranges are small and define a good thermo-responsive bioink, they do not generate a filament on the air and make drops during extrusion. In conclusion, this bioink provides a very stable behavior with low shear stress, but other bioprinting parameters must be set up to get a stable filament width.

CFD simulation on centrifugal pump impeller with splitter blades

ABSTRACT The present paper aims to present the analysis and comparison of results of computational simulations using Computational Fluids Dynamics (CFD) in impellers of centrifugal pump. Three impellers were simulated: 1) original impeller, 2) original impeller with splitter blades at outlet; 3) original impeller with splitter blades at inlet. The splitters occupied 30% of the length of the main blades. They were simulated using the ANSYS-CFX software system in 1500 rpm rotational speed and at different flow rates. The turbulence model assumed was the Shear Stress Transport (SST). The results were used to build impeller blade head curves, besides the presentation of pressure distribution and streamline behaviour inside the impeller. It was verified that the insertion of the splitter blades reduced the impeller blade head, mainly the impeller with outlet splitter, whose reduction was more intense.