scholarly journals Simulasi Sistem Aliran Massa Pneumatic Grain Conveyor Kapasitas 135 Ton/Jam

2021 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Muhammad Ridwan ◽  
Andri Surya ◽  
Irga Nugraha
Keyword(s):  
Boundary Conditions ◽  
Moving Objects ◽  
Inlet Pipe ◽  
Pressure System ◽  
Simulation Process ◽  
Displacement Capacity ◽  
Pipe Section ◽  
Outlet Pipe ◽  
Simulation Results ◽  
Design Result

Abstrak Pneumatic grain conveyor adalah sebuah alat untuk memindahkan benda yang berbentuk serbuk atau butir dengan memanfaatkan udara sebagai media pemindahan. Conveyor yang cocok digunakan untuk memindahkan butiran-butiran seperti gandum dengan cepat adalah bertipe pneumatic grain conveyor yang memanfaatkan fluida udara sebagai media untuk memindahkan butiran. Proses simulasi ini dilakukan untuk membuktikan sejauh mana kapasitas perancangan 135 ton/jam dapat dicapai oleh conveyor hasil perancangan. Pneumatic grain conveyor yang dirancang menggunakan sistem tekanan kombinasi, proses simulasi dilakukan pada jalur aliran gandum yang meliputi 3 bagian menyambung yaitu inlet pipe, cyclone, dan outlet pipe. Boundary conditions pada bagian inlet pipe menggunakan data dari hasil perancangan, sedangkan pada cyclone dan outlet pipe menggunakan data dari hasil simulasi pada bagian sebelumnya. Hasil simulasi menunjukkan bahwa kapasitas pemindahan dari conveyor adalah sebesar 26,653 ton/jam. Laju aliran gandum dapat mencapai fasa dilute phase serta cyclone berfungsi dengan baik dalam memisahkan gandum dengan udara.  Kata kunci : pneumatic grain conveyor, inlet pipe, cyclone , outlet pipe, simulasi. Abstract Pneumatic grain conveyor is a tool for moving objects in the form of powder or grain by utilizing air as a transfer medium. Conveyors that are suitable for moving granules quickly such as wheat are pneumatic grain conveyor, that use air fluid to move the grain. This simulation process is carried out to prove the extent to which the design capacity of 135 tons / hour can be achieved by the designed conveyor. Pneumatic grain conveyor designed using a combination pressure system, the simulation process is carried out on the grain flow path which includes 3 connecting parts, namely inlet pipe, cyclone, dan outlet pipe. Boundary conditions in the inlet pipe section use data from the design result, while the cyclone and outlet pipe section use data from the simulation results in the previous section. The simulation results show that the displacement capacity of the conveyor is 26.653 tons / hour. The flow rate of wheat can reach the phase of the dilute phase and the cyclone works well in separating wheat with air.  Keywords : pneumatic grain conveyor, inlet pipe, cyclone, outlet pipe, simulation.

scholarly journals Impurity induced scale-free localization

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Linhu Li ◽  
Ching Hua Lee ◽  
Jiangbin Gong
Keyword(s):  
Boundary Conditions ◽  
Skin Effect ◽  
Reciprocal Lattice ◽  
Periodic Boundary Conditions ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Translational Invariance ◽  
Scale Free ◽  
Special Cases ◽  
Simulation Results

AbstractNon-Hermitian systems have been shown to have a dramatic sensitivity to their boundary conditions. In particular, the non-Hermitian skin effect induces collective boundary localization upon turning off boundary coupling, a feature very distinct from that under periodic boundary conditions. Here we develop a full framework for non-Hermitian impurity physics in a non-reciprocal lattice, with periodic/open boundary conditions and even their interpolations being special cases across a whole range of boundary impurity strengths. We uncover steady states with scale-free localization along or even against the direction of non-reciprocity in various impurity strength regimes. Also present are Bloch-like states that survive albeit broken translational invariance. We further explore the co-existence of non-Hermitian skin effect and scale-free localization, where even qualitative aspects of the system’s spectrum can be extremely sensitive to impurity strength. Specific circuit setups are also proposed for experimentally detecting the scale-free accumulation, with simulation results confirming our main findings.

Finite Element Simulation of Laser Beam Welding Induced Residual Stresses and Distortions in a T-Joint Configuration for Aeronautic Structures

2009 ◽  
Author(s):  
Muhammad Zain-ul-abdein ◽  
Daniel Ne´lias ◽  
Jean-Franc¸ois Jullien ◽  
Dominique Deloison
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Laser Beam ◽  
Boundary Conditions ◽  
Laser Beam Welding ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Small Scale ◽  
Joint Configuration ◽  
Simulation Results

Laser beam welding has found its application in the aircraft industry for the fabrication of fuselage panels in a T-joint configuration. However, the inconveniences like distortions and residual stresses are inevitable consequences of welding. The effort is made in this work to experimentally measure and numerically simulate the distortions induced by laser beam welding of a T-joint with industrially used thermal and mechanical boundary conditions on the thin sheets of aluminium 6056-T4. Several small scale experiments were carried out with various instrumentations to establish a database necessary to verify the simulation results. Finite element (FE) simulation is performed with Abaqus and the conical heat source is programmed in FORTRAN. Heat transfer analysis is performed to achieve the required weld pool geometry and temperature fields. Mechanical analysis is then performed with industrial loading and boundary conditions so as to predict the distortion and the residual stress pattern. A good agreement is found amongst the experimental and simulation results.

Study on the Cyclic Loading Effects to the Railway Ballast

2013 ◽  
Vol 724-725 ◽  
pp. 1736-1739
Author(s):  
Xue Jun Wang ◽  
Bin Hua ◽  
Yi Lin Chi ◽  
Xue Yu Zhao ◽  
Fu Yu Li
Keyword(s):  
Cyclic Loading ◽  
Research Method ◽  
Flow Simulation ◽  
Railway Ballast ◽  
Compaction Rate ◽  
Simulation Process ◽  
Loading Effects ◽  
Simulation Results ◽  
Frequency Changes ◽  
Particle Flow Simulation

When ballast materials are subjected to cyclic loading, as a result, the change of particles micromechanical properties will lead to ballast degradation, permanent deformations on the railways step by step. In this paper, it presented a coupling discrete particle-flow simulation model of the railway ballast for cyclic tamping loading. Tamping frequency changes from 25HZ to 60HZ in numerical simulation process. Simulation results that the ballast compaction rate increases linearly with frequency up to a characteristic frequency 35HZ and then it declines in inverse proportion to tamping frequency. The aim of this paper is to study on the effects on the railway ballast under cyclic loading. The study shows that the discrete element method is a valid method for investigation of the microscopic properties of railway ballast now, while we have no other better research method.

scholarly journals Small Caliber Bulletproof Test of Warships’ Hulls

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3848
Author(s):  
Radosław Kiciński ◽  
Andrzej Kubit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Method Simulation ◽  
Material Model ◽  
Experimental Results ◽  
Material Constants ◽  
Steel Core ◽  
Calculation Results ◽  
Simulation Results

The article presents the characteristics of 1.3964 steel and the results of firing a 7.62 mm projectile with a steel core. A simplified Johnson–Cook material model for steel and projectile was used. Then, a FEM (finite element method) simulation was prepared to calibrate the material constants and boundary conditions necessary to be used in simulations of the entire hull model. It was checked how projectile modeling affects the FEM calculation results. After obtaining the simulation results consistent with the experimental results, using the model of a modern minehunter, the resistance of the ship’s hull to penetration by a small-caliber projectile was tested.

Numerical modeling of multiple length scales in thermal transport processes

2014 ◽  
Vol 24 (4) ◽  
pp. 781-796 ◽  
Author(s):  
Yogesh Jaluria
Keyword(s):  
Numerical Modeling ◽  
Boundary Conditions ◽  
Time Scales ◽  
Transport Processes ◽  
Thermal Processes ◽  
Length Scales ◽  
Content Type ◽  
Multiple Length Scales ◽  
Wide Range ◽  
Simulation Results

Purpose – Multiple length and time scales arise in a wide variety of practical and fundamental problems. It is important to obtain accurate and validated numerical simulation results, considering the different scales that exist, in order to predict, design and optimize the behavior of practical thermal processes and systems. The purpose of this paper is to present modeling at the different length scales and then addresses the question of coupling the different models to obtain the overall model for the system or process. Design/methodology/approach – Both numerical and experimental methods to obtain results at the different length scales, particularly at micro and nanoscales, are considered. Even though the paper focusses on length scales, multiple time scales lead to similar concerns and are also considered. The two circumstances considered in detail are multiple length scales in different domains and those in the same domain. These two cases have to be modeled quite differently in order to obtain a model for the overall process or system. The basic considerations involved in such a modeling are discussed. A wide range of thermal processes are considered and the methods that may be used are presented. The models employed must be validated and the accuracy of the simulation results established if the simulation results are to be used for prediction, control and design. Findings – Of particular interest are concerns like verification and validation, imposition of appropriate boundary conditions, and modeling of complex, multimode transport phenomena in multiple scales. Additional effects such as viscous dissipation, surface tension, buoyancy and rarefaction that could arise and complicate the modeling are discussed. Uncertainties that arise in material properties and in boundary conditions are also important in design and optimization. Large variations in the geometry and coupled multiple regions are also discussed. Research limitations/implications – The paper is largely focussed on multiple-scale considerations in thermal processes. Both numerical modeling/simulation and experimentation are considered, with the latter being used for validation and physical insight. Practical implications – Several examples from materials processing, environmental flows and electronic systems, including data centers, are given to present the different techniques that may be used to achieve the desired level of accuracy and predictability. Originality/value – Present state of the art and future needs in this interesting and challenging area are discussed, providing the impetus for further work. Different methods for treating multiscale problems are presented.

Geometrical Modelling of Jacquard Quilted Structures Weft Knitted Fabrics

2016 ◽  
Vol 11 (1) ◽  
pp. 155892501601100
Author(s):  
Lanming Jin ◽  
Gaoming Jiang ◽  
Honglian Cong ◽  
Chenguang Hou
Keyword(s):  
3D Model ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Knitted Fabric ◽  
Loop Model ◽  
Visual Effects ◽  
Knitted Fabrics ◽  
Simulation Process ◽  
Geometrical Modelling ◽  
Simulation Results

Jacquard quilted structure weft-knitted fabrics have many advantages, such as strong stereoscopic patterns, soft handling, adjustable apparel thickness, and use as home textiles. However, the final visual effects of such fabrics are difficult to predict prior to processing because of the rough surface caused by the connecting yarn and the inlay yarn of the fabric. This research applied a three-dimensional (3D) model instead of the original single-loop model to simulate knitted fabric. The 3D model is more suitable for a multilayer fabric because the simulation is quick, real, and convenient. The article includes experiments on structural parameters concerning regular dents of different samples, analysis of parameter data about the surface, and the simulation process with the objective of understanding the computer simulation of fabric. Results show good correlation between the simulation results and the actual fabric. Importantly, we can clearly see the expected effects in the fabrics without going through production and processing. This research will be useful for establishing a quick computer-generated simulation system for multilayer fabrics.

Effects of Microjets in Flow Over a Backward-Facing Step

2012 ◽  
Author(s):  
H. Kanchi ◽  
F. Mashayek
Keyword(s):  
Passive Scalar ◽  
Streamwise Velocity ◽  
Inlet Pipe ◽  
Backward Facing Step ◽  
Passive Scalars ◽  
Eddy Simulation ◽  
Pipe Section ◽  
Large Eddy ◽  
Normal Fluctuations ◽  
Good Agreement

Large eddy simulation is used to study the flow over a backward-facing step interacting with a periodic array of streamwise microjets emenating from the step at a 45° angle to the step face. Averaged streamwise velocity profiles are in good agreement with experimental data. A well defined turbulent inlet profile for the microjet is found to be important to obtain correct streamwise normal fluctuations near the step. To simulate cases as per the experimental setup a microjet inlet pipe section is necessary for the simulations. The studies with passive scalars need to be conducted to quantify scalar mixing. The monotonicity problem of simulating passive scalar can be overcome by simply clipping the unbounded values. This technique works because the volume occupied by overshoot values of passive scalar are small compared to the total volume of the backward-facing step geometry.

Modeling and Simulation of Dynamic Mass Capture by Robot Manipulators Considering Structural Flexiblity

1998 ◽  
Author(s):  
J. Kövecses ◽  
W. L. Cleghorn ◽  
R. G. Fenton
Keyword(s):  
Degrees Of Freedom ◽  
Moving Objects ◽  
Second Phase ◽  
Finite Motion ◽  
Dynamic Mass ◽  
Mass Capture ◽  
Alternative Approach ◽  
Impulsive Constraints ◽  
Simulation Results ◽  
Good Agreement

Abstract In this paper we investigate the dynamics of the process when a robot intercepts and captures a moving object. This operation is called dynamic mass capture. The effects of structural flexibility of the robot is taken into consideration. In terms of time the analysis is divided into three phases: before interception (finite motion), at the vicinity of interception and capture (impulsive motion), and after interception (finite motion). Special attention is paid to the modeling of the second phase when the robot intercepts and captures a target and it becomes part of the end effector, thus, the system’s degrees of freedom and topology suddenly change. To describe this event, an alternative approach is proposed. This is based on the use of a class of impulsive constraints, the so-called inert constraints. Jourdain’s principle is employed to derive the dynamic equations for both finite and impulsive motions. Based on the proposed approach, simulation results are presented for a flexible slewing link capturing a moving target. These results are compared with the observations of an experiment. Good agreement is found between the experimental and simulation results, which suggests that the analysis presented in this paper can be used with confidence in investigations of robots intercepting and capturing moving objects.

The Study of Interpolation Algorithms in OFDM Systems

2013 ◽  
Vol 321-324 ◽  
pp. 2837-2840
Author(s):  
Xi Jun Zhang ◽  
Jian Bin Xue ◽  
Ying Lin ◽  
Ji Ai He
Keyword(s):  
Channel Estimation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Simulation Process ◽  
Interpolation Algorithms ◽  
Simulation Results

Orthogonal frequency division multiplexing (OFDM) is a kind of highly transmission technology. It has been taken more and more attention in many ways. In this paper it mainly discussed the simulation process and several interpolation algorithms in OFDM system. Using computer we simulate the interpolation algorithms in OFDM channel estimation. Through the simulation results we compare the advantage and disadvantage of the interpolation algorithms. At last we can use the conclusion to choose the correct interpolation algorithms in OFDM channel estimation.

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