scholarly journals Optimasi Gasifikasi Serbuk Tandan Kosong Kelapa Sawit Menggunakan Powder Gasifier Type Cyclone

2019 ◽  
Vol 39 (3) ◽  
pp. 258
Author(s):  
Riksa Prayogi Widyaprawira ◽  
Radi Radi ◽  
Bambang Purwantana
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Fluid Velocity ◽  
Mass Rate ◽  
Empty Fruit Bunches ◽  
Fuel Ratio ◽  
Gasification Process ◽  
Air Speed ◽  
Fresh Fruit Bunches ◽  
Cfd Method

Every year, palm-oil production is increasing. Each ton of fresh fruit bunches produced to 22%–23% of oil palm empty fruit bunches (OPEFB). Based on the laboratory test, OPEFB contains 69,72% volatile and 3353,97 kcal/kg of calor. Aim of the research is to determine size material OPEFB in gasification process, determine combination AFR (Air Fuel Ratio) in gasifier tipe cyclone so that produce optimal energy and to prediction gasification process with CFD method (Computational Fluid Dynamic). The powder gasifier cyclone type method is used to convert this into renewable energy. The research method consists of OPEFB powder material with 14, 30 and 50 mesh treatment, 4 air-fuel ratio, and material mass rate treatments, and variations of the length of middle-pipe treatment. The weight of each sample is 500 g, added with 100 g of charcoal and repeated 3 times. The result shows the mesh A3 has the highest temperature at 348.23 °C, 1008,68 kcal/kg of heat value, 30.07% of efficiency, 97.81 kg/kg of AFR value, but has the lowest engine working capacity (EWC) with 14.65 kg/hours. Based on sensor test, A3 treatment, the voltage of monoxide sensor output is 1.45 mV; 1.81 mV of hydrogen; and methane at 0.66 mV. In the combination of air speed and screw rotational treatment, AFR values were generated by treatment B4 with EWC value of 20 kg/hour and AFR of 97.1 kg/kg. The highest gasmonoxide sensor results in treatment B4 is 1.58 mV; hydrogen 1.98 mV. Based on the length of the enter pipe in the reactor, treatment C1 produces an optimal value of the EWC value at 16.6 kg/hour, the heat energy value is 997 kcal/kg, the efficiency value is 29.73% and the AFR value is 82,87 kg/kg. In treatment C1 the gas monoxide sensor voltage is 1.6 mV; and methane is 1.46 mV. The CFD simulation shows that the distribution of temperature, fluid velocity and pressure in the middle iteration have a significant increase. This can be influenced by the dimensions of powder gasifier cyclone type with CFD simulation.

CFD Simulation Study of Gas-Liquid Flow Regimes in Inclined Wellbore

2014 ◽  
Vol 915-916 ◽  
pp. 126-130
Author(s):  
Yin Di Zhang ◽  
Long Fei Ruan ◽  
De Hua Liu
Keyword(s):  
Inclination Angle ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Flow Regimes ◽  
Two Phase ◽  
Flow Rates ◽  
Flow Regime Transition ◽  
Gas Liquid Flow ◽  
Cfd Method ◽  
Good Agreement

Computational Fluid Dynamic (CFD) was used to investigate gas-liquid two phase flow regimes for the inclined wells. The simulation results were compared with the Taitel chart. A good agreement between the prediction and the Taitel flow regimes shows that CFD method can reasonably predict flow regimes in the inclined well. Another further study was conducted to explore the influence of flow rates and inclination angle on flow regimes. The results show both of flow rates and inclination angle have a significant effect on flow regime transition.

Research on Wind Energy Exploitation in Buildings Environment

2012 ◽  
Vol 178-181 ◽  
pp. 120-126
Author(s):  
Hua Shu Chen ◽  
Guang Hong Hu ◽  
Ming Chiu Tu
Keyword(s):  
Wind Energy ◽  
Wind Field ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Pressure Coefficient ◽  
Simulation Method ◽  
Wind Pressure ◽  
Wind Pressure Coefficient ◽  
Cfd Method ◽  
Energy Exploitation

The flow fields in different monsoon periods of Shanghai Mengqing Garden were analyzed by computational fluid dynamic (CFD) simulation method. At the same time, the wind energy value in the Shanghai Mengqing Garden was also evaluated by CFD method. And the suggested wind turbines arrangement was proposed based on the wind field results. Safety of the buildings around the garden was analyzed by comparing the change of the wind pressure coefficient. At last, the results show that the wind field in urban building environment is available for wind energy exploitation.

scholarly journals Impeller Optimization in Crossflow Hydraulic Turbines

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 313
Author(s):  
Marco Sinagra ◽  
Calogero Picone ◽  
Costanza Aricò ◽  
Antonio Pantano ◽  
Tullio Tucciarelli ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Structural Safety ◽  
3D Fem ◽  
Good Efficiency ◽  
Standard Material ◽  
Variable Head ◽  
Hydraulic Turbines ◽  
Constructive Simplicity ◽  
Mechanical Optimization

Crossflow turbines represent a valuable choice for energy recovery in aqueducts, due to their constructive simplicity and good efficiency under variable head jump conditions. Several experimental and numerical studies concerning the optimal design of crossflow hydraulic turbines have already been proposed, but all of them assume that structural safety is fully compatible with the sought after geometry. We show first, with reference to a specific study case, that the geometry of the most efficient impeller would lead shortly, using blades with a traditional circular profile made with standard material, to their mechanical failure. A methodology for fully coupled fluid dynamic and mechanical optimization of the blade cross-section is then proposed. The methodology assumes a linear variation of the curvature of the blade external surface, along with an iterative use of two-dimensional (2D) computational fluid dynamic (CFD) and 3D structural finite element method (FEM) simulations. The proposed methodology was applied to the design of a power recovery system (PRS) turbine already installed in an operating water transport network and was finally validated with a fully 3D CFD simulation coupled with a 3D FEM structural analysis of the entire impeller.

scholarly journals Computational fluid dynamics (CFD) simulation analysis on retinal gas cover rates using computational eye models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Makoto Gozawa ◽  
Yoshihiro Takamura ◽  
Tomoe Aoki ◽  
Kentaro Iwasaki ◽  
Masaru Inatani
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Fluid Dynamic ◽  
Fluid Analysis ◽  
Intraocular Gas ◽  
Pars Plana ◽  
Computational Fluid Dynamics Cfd ◽  
Multiple Breaks ◽  
Gas Volume ◽  
Wall Wettability

AbstractWe investigated the change in the retinal gas cover rates due to intraocular gas volume and positions using computational eye models and demonstrated the appropriate position after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachments (RRDs). Computational fluid dynamic (CFD) software was used to calculate the retinal wall wettability of a computational pseudophakic eye models using fluid analysis. The model utilized different gas volumes from 10 to 90%, in increments of 10% to the vitreous cavity in the supine, sitting, lateral, prone with closed eyes, and prone positions. Then, the gas cover rates of the retina were measured in each quadrant. When breaks are limited to the inferior retina anterior to the equator or multiple breaks are observed in two or more quadrants anterior to the equator, supine position maintained 100% gas cover rates in all breaks for the longest duration compared with other positions. When breaks are limited to either superior, nasal, or temporal retina, sitting, lower temporal, and lower nasal position were maintained at 100% gas cover rates for the longest duration, respectively. Our results may contribute to better surgical outcomes of RRDs and a reduction in the duration of the postoperative prone position.

scholarly journals Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe

2008 ◽  
Vol 10 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Roch Plewik ◽  
Piotr Synowiec ◽  
Janusz Wójcik
Keyword(s):  
Cfd Simulation ◽  
Fluidised Bed ◽  
Cfd Simulations ◽  
Two Phase ◽  
Hydraulic Behaviour ◽  
Hydraulic Conditions ◽  
The One ◽  
Cfd Method ◽  
Multi Phase ◽  
The Ideal

Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe The hydrodynamics in fluidized-bed crystallizers is studied by CFD method. The simulations were performed by a commercial packet of computational fluid dynamics Fluent 6.x. For the one-phase modelling (15), a standard k-ε model was applied. In the case of the two-phase flows the Eulerian multi-phase model with a standard k-ε method, aided by the k-ε dispersed model for viscosity, has been used respectively. The collected data put a new light on the suspension flow behaviour in the annular zone of the fluidised bed crystallizer. From the presented here CFD simulations, it clearly issues that the real hydraulic conditions in the fluidised bed crystallizers are far from the ideal ones.

scholarly journals Simulation of Hydraulic Cylinder Cushioning

2021 ◽  
Vol 13 (2) ◽  
pp. 494
Author(s):  
Antonio Algar ◽  
Javier Freire ◽  
Robert Castilla ◽  
Esteban Codina
Keyword(s):  
Dynamic Model ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Computational Fluid Dynamic Simulation ◽  
Hydraulic Cylinder ◽  
Outlet Port ◽  
Optimal Behavior ◽  
Radial Movement ◽  
Mechanical Shocks ◽  
Radial Gap

The internal cushioning systems of hydraulic linear actuators avoid mechanical shocks at the end of their stroke. The design where the piston with perimeter grooves regulates the flow by standing in front of the outlet port has been investigated. First, a bond graph dynamic model has been developed, including the flow throughout the internal cushion design, characterized in detail by computational fluid-dynamic simulation. Following this, the radial movement of the piston and the fluid-dynamic coefficients, experimentally validated, are integrated into the dynamic model. The registered radial movement is in coherence with the significant drag force estimated in the CFD simulation, generated by the flow through the grooves, where the laminar flow regime predominates. Ultimately, the model aims to predict the behavior of the cushioning during the movement of the arm of an excavator. The analytical model developed predicts the performance of the cushioning system, in coherence with empirical results. There is an optimal behavior, highly influenced by the mechanical stress conditions of the system, subject to a compromise between an increasing section of the grooves and an optimization of the radial gap.

Mapping of protein fouling by FTIR-ATR as experimental tool to study membrane fouling and fluid velocity profile in various geometries and validation by CFD simulation

2008 ◽  
Vol 47 (7) ◽  
pp. 1106-1117 ◽  
Author(s):  
David Delaunay ◽  
Murielle Rabiller-Baudry ◽  
José M. Gozálvez-Zafrilla ◽  
Béatrice Balannec ◽  
Matthieu Frappart ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Membrane Fouling ◽  
Cfd Simulation ◽  
Fluid Velocity ◽  
Protein Fouling ◽  
Experimental Tool

CFD Simulation of a Co-rotating Twin-screw Extruder: Validation of a Rheological Model for a Starch-Based Dough for Snack Food

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Giorgia Tagliavini ◽  
Federico Solari ◽  
Roberto Montanari
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Second Phase ◽  
Snack Food ◽  
Suitable Model ◽  
Twin Screw Extruder ◽  
Parallel Plates ◽  
Screw Extruder ◽  
Twin Screw

AbstractThe extrusion of starch-based products has been a matter of interest, especially for the pasta and the snack food production. In recent years, twin-screw extruders for snack food have been studied from both structural and fluid dynamics viewpoints. This project started from the rheological characterization of a starch-based dough (corn 34 wt%, tapioca 32 wt%), comparing viscosity values acquired in laboratory with different theoretical models found in literature. A computational fluid dynamic (CFD) simulation recreating the simple case of a fluid flow between two parallel plates was carried out to validate the former comparison. After the rheological validation was completed, the second phase of this work covered a 3D CFD simulation of the first part of the twin-screw extruder (feeding zone). The objective was to find a suitable model for describing the dough rheological behavior and the operating conditions of a co-rotating intermeshing twin-screw extruder. Once the model would be defined, it would allow to investigate several working conditions and different screws geometries of the machine, predicting the evolution of the product rheological properties.

Optimization of a Biomass Micro-Gasification Process for the Production of Synthesis Gas From Palm Shell

2015 ◽  
Author(s):  
Luz M. Ahumada ◽  
Arnaldo Verdeza ◽  
Antonio J. Bula
Keyword(s):  
Particle Size ◽  
Fixed Bed ◽  
High Energy ◽  
Operating Conditions ◽  
Air Velocity ◽  
Output Variable ◽  
Heating Value ◽  
Palm Shell ◽  
Gasification Process ◽  
Air Speed

This paper studied, through an experiment design, the significance of particle size, air speed and reactor arrangement for palm shell micro-gasification process in order to optimize the heating value of the syngas obtained. The range of variables was 8 to 13 mm for particle size, 0.8–1.4m/s for air velocity, and updraft or downdraft for the reactor type. It was found that the particle size and air velocity factors were the most significant in the optimization of the output variable, syngas heating value. A heating value of 2.69MJ / Nm3 was obtained using a fixed bed downdraft reactor, with a particle size of 13 mm and 1.4 m/s for air speed; verification of the optimum point of operation under these conditions verified that these operating conditions favor the production of a gas with a high energy value.

Hydraulic Characteristics of the New Type Bulb Turbine With Micro-Head

2013 ◽  
Author(s):  
Lingyu Li ◽  
Yuan Zheng ◽  
Daqing Zhou ◽  
Zihao Mi
Keyword(s):  
Numerical Simulation ◽  
Cfd Simulation ◽  
Guide Vane ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Three Dimensions ◽  
Guide Vanes ◽  
Runner Blade ◽  
Cfd Method ◽  
Bulb Turbine

The head of low-head hydropower stations is generally higher than 2.5m in the world, while micro-head hydropower resources which head is less than 2.5m are also very rich. In the paper, three-dimensional CFD method has been used to simulate flow passage of the micro-head bulb turbine. The design head and unit flow of the turbine was 1m and 3m3/s respectively. With the numerical simulation, the bulb turbine is researched by analyzing external characteristics of the bulb turbine, flow distribution before the runner, pressure distribution of the runner blade surface, and flow distribution of the outlet conduit under three different schemes. The turbine in second scheme was test by manufactured into a physical model. According to the results of numerical simulation and model test, bulb turbine with no guide vane in second scheme has simpler structure, lower cost, and better flow capacity than first scheme, which has traditional multi-guide vanes. Meanwhile, efficiency of second scheme has just little decrease. The results of three dimensions CFD simulation and test results agree well in second scheme, and higher efficiency is up to 77% which has a wider area with the head of 1m. The curved supports in third scheme are combined guide vanes to the fixed supports based on 2nd scheme. By the water circulations flowing along the curved supports which improve energy transformation ability of the runner, the efficiency of the turbine in third scheme is up to 82.6%. Third scheme, which has simpler structure and best performance, is appropriate for the development and utilization of micro-head hydropower resources in plains and oceans.

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