FDTD Modeling of Realistic Microwave Sintering Experiments

1994 ◽  
Vol 347 ◽  
Author(s):  
Zhenlong Huang ◽  
Magdy F. Iskander ◽  
James Tucker ◽  
Hal D. Kimrey
Keyword(s):  
Numerical Simulation ◽  
New Technology ◽  
Microwave Sintering ◽  
Scale Up ◽  
Solution Procedure ◽  
Uniform Grid ◽  
Transfer Program ◽  
Microwave Cavities ◽  
Electromagnetic Power ◽  
Variable Mesh

ABSTRACTComputer modeling and numerical simulation provide a valuable tool for providing guidelines towards a successful routine experimentation with microwave sintering of ceramics. It is also expected that continued efforts in numerical simulation will lead to establishing procedures for the scale up and commercial utilization of this new technology.In this paper, we utilize the FDTD technique to model sintering ceramics in multimode microwave cavities. The role of using process stimulus such as SiC rods on improving the uniformity of the microwave sintering process are also simulated. To help experimentally validate the obtained results, the FDTD electromagnetic power deposition results were combined with a 3D heat transfer program to calculate temperature distribution in samples and surrounding insulation. Results from the FDTD codes and comparisons with experimental measurements of sintering experiments are presented.To improve the efficiency of the simulation and achieve more accurate results, we developed a variable mesh FDTD code to help focus the numerical results and hence improve the resolution in critical sites inside the sintering oven. Detailed solution procedures are described. We solved some test geometries with the uniform grid and the developed variable mesh codes and compared the obtained results to validate and check the accuracy of the solution procedure. Results from these comparisons are presented.

Calculation of Heating Patterns in Microwave Sintering using a 3D Finite-Difference Code

1994 ◽  
Vol 347 ◽  
Author(s):  
James Tucker ◽  
Magdy F. Iskander ◽  
Zhenlong Huang
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Finite Difference ◽  
Microwave Sintering ◽  
Scale Up ◽  
Companion Paper ◽  
Temperature Pattern ◽  
Measured Temperature ◽  
Limited Information ◽  
Transfer Program

ABSTRACTAnalysis of heating patterns in microwave sintering experiments provide information on the contributions of the various heat transfer components to the overall temperature pattern. Measured temperature patterns provide limited information on overall effects. Numerical simulations provide a cost effective way from which the effect of geometry, material properties and the presence of stimulus such as SiC rods or sheets on the heating pattern can be studied separately. Parametric studies allow us to identify the most significant properties and provide guidelines for the routine successful utilization of microwave sintering experiments. These guidelines may also facilitate the scale up and commercialization of microwave sintering.In this paper we describe a thermal model that calculates the temperature distribution in ceramic samples and insulation under realistic microwave sintering conditions. The calculation process involves a two-step procedure. The first step is to calculate the microwave power deposition in the sample and surrounding insulation. 3D FDTD calculations, described in a companion paper[1,2], are used for this purpose. The other step involves calculation of the temperature distribution using a 3D finite-difference heat-transfer program developed in our Departments[3]. Results illustrating the effect of thickness of insulation and the placement of SiC rod susceptors in picket-fence arrangement are presented.

Querfließpressen und Verschieben*/Lateral extrusion and shifting

2017 ◽  
Vol 107 (10) ◽  
pp. 708-713
Author(s):  
M. Prof. Liewald ◽  
L. Pasler
Keyword(s):  
Numerical Simulation ◽  
New Technology ◽  
Cold Forging ◽  
Forming Process ◽  
Tensile Stresses ◽  
Lateral Extrusion

Mit dem neu entwickelten Verfahren, das Querfließpressen mit gleichzeitigem Verschieben kombiniert, lassen sich exzentrische Wellen oder kurbelwellenartige Bauteile durch Kaltfließpressen herstellen. Der Vorteil im Unterschied zur Verfahrenskombination von Stauchen und anschließendem Verschieben ist, dass das Querfließpressen ein Nachführen von Material während des Umformprozesses in die Umformzone ermöglicht. Aufgrund der verfahrensbedingten geringeren Zugspannungen in der Kurbelwange sind mit dem neuen Verfahren erweiterte Verfahrensgrenzen beim Versatz zu erwarten. Dieser Fachbeitrag beschreibt das Verfahrensprinzip, das Werkzeugkonzept und die numerische Auslegung des Prozesses.   The new technology of combined lateral extrusion and simultaneous shifting allows producing eccentric shafts or crankshaft-like components by cold forging. The advantage of lateral extrusion compared to an upsetting and subsequent shifting is the constant web thickness. For this, material is pushed into the forming zone during the forming process. It is expected that this will result in lower tensile stresses and thus lower damage in the crankshaft web. This paper describes the process, tooling concept and numerical simulation of the combined lateral extrusion and shifting process.

scholarly journals Exploring and Preparing for Successful Cross-continental Knowledge and Technology Transfer: A Case Study on International Open Innovation

2019 ◽  
Vol 5 (1) ◽  
pp. 60-76
Author(s):  
Alan Barrell ◽  
Joanne Hsu
Keyword(s):  
Technology Transfer ◽  
New Technology ◽  
Scale Up ◽  
Close Collaboration ◽  
Group A ◽  
Energy Innovation ◽  
Knowledge And Technology Transfer ◽  
The Uk ◽  
Rapid Transfer

Shanghai Energy Corporation—SHEnergy Group, a major Chinese enterprise in energy provision and the development of continuous improvements in energy conservation within urban development, is undertaking a major initiative in establishing the Shanghai International Energy Innovation Centre (SIEIC). Within the programme, study visits to London and Cambridge in the UK led to a decision to seek close collaboration with established and mature centres of excellence in technology transfer and the support of new company development and scale up, providing the rapid transfer of methodology and process and in addition to establishing longer term connections and relationships enabling the identification, curation, funding and eventual adoption of promising new technology from Cambridgexf and other UK and Western centres by SIEIC—in ways bringing benefits to all parties.

Simulation and scale-up of the desulphurization of gas streams by adsorption method using numerical simulation

2020 ◽  
Vol 84 ◽  
pp. 103693
Author(s):  
João Paulo Lobo dos Santos ◽  
Ana Katerine de Carvalho Lima Lobato ◽  
Caetano Moraes ◽  
Acto de Lima Cunha ◽  
José Jailton Marques ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Scale Up ◽  
Adsorption Method ◽  
Gas Streams

Dispersion of Twin Inclined Fume Jets of a Variable Height within a CrossFlow

2011 ◽  
Vol 312-315 ◽  
pp. 929-934 ◽  
Author(s):  
Amina Radhouane ◽  
Nejla Mahjoub Said ◽  
Hatem Mhiri ◽  
Georges Le Palec ◽  
Philippe Bournot
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Finite Volume Method ◽  
Single Particle ◽  
Mass Fraction ◽  
Uniform Grid ◽  
Grid System ◽  
Dispersion Process ◽  
Volume Method ◽  
The Impact

Twin elliptic inclined tandem jets are emitted within an oncoming cooler crossflow. The jets contain a non reactive fume whose dispersion is tracked all over the surrounding domain. Such a configuration may be found in chimney stacks, ships’ chimneys, etc. We propose to evaluate in the present paper the impact of the jets’ height on the resulting dispersion process. To reach this goal, a numerical simulation of a double jet model of variable height is carried out by means of the finite volume method together with a non uniform grid system. The model, validated by previous experimental data, allowed the tracking of the emitted fume by studying the evolution of a single particle contained within this fume, the Carbone dioxide (CO2) mass fraction. This is possible thanks to the assumption of handling a non reactive fume, which is adopted only to simplify the calculations. The CO2 mass fraction was mainly tracked between the emitting nozzles, in a try to find out the changes brought by the extension of the emitting jet nozzles on the flow trapped between them.

scholarly journals Translating Evidence-Based Program Recommendations into Action: The Design, Testing, and Scaling Up of the Behavior Change Strategy EsIAN in Mexico

2019 ◽  
Vol 149 (Supplement_1) ◽  
pp. 2310S-2322S ◽  
Author(s):  
Anabelle Bonvecchio Arenas ◽  
Wendy González ◽  
Florence L Théodore ◽  
Ana Lilia Lozada-Tequeanes ◽  
Armando Garcia-Guerra ◽  
...  
Keyword(s):  
Behavior Change ◽  
Feasibility Study ◽  
Iterative Process ◽  
Scale Up ◽  
Formative Research ◽  
Evidence Based ◽  
Transfer Program ◽  
National Scale ◽  
Supplement Use ◽  
Roll Out

ABSTRACT Background The Integrated Strategy for Attention to Nutrition (EsIAN in Spanish) is a national strategy within Mexico's conditional cash transfer program (initially Progresa, then Oportunidades, then Prospera, CCT-POP) designed to strengthen the health and nutrition component, address the nutrition transition, and improve the health and nutritional status of its beneficiaries, through 3 main components: 1) procurement of functioning equipment to primary health care (PHC) units; 2) providing free micronutrient supplements to beneficiary women and children; 3) implementing a behavior change communication (BCC) strategy and a training system for PHC providers (PHCPs). Objective We aim to describe the iterative process and evidence-based approach used to design and roll-out the EsIAN at scale, by focusing on the BCC component. Methods The BCC strategy was developed by following an iterative process through the following phases: situational analysis, formative research and design of the BCC strategy (using the socioecological framework and the social marketing approach), large-scale feasibility study, redesign, and national scale-up. Results The review and formative research revealed several barriers and issues that limited program coverage, utilization, and acceptance. These included misconceptions about pregnancy and infant feeding, nonalignment of practices with international recommendations, and lack of knowledge on nutrition and related topics, among others. These results were used to identify priority behaviors and elaborate key messages for mothers/caregivers and providers to develop the BCC strategy. The feasibility study resulted in significant improvements in PHCPs’ knowledge, counseling (breastfeeding, and supplement use and consumption), and caregivers’ complementary feeding behaviors, and highlighted several design and delivery aspects that needed strengthening. Based on these findings, the BCC strategy was adapted prior to a national scale-up. Conclusions The theory-based iterative approach resulted in the identification of specific actions to target, and approaches to do so, as part of the design and roll-out of the BCC strategy at scale.

Numerical simulation of the evolution of Tollmien–Schlichting waves over finite compliant panels

1997 ◽  
Vol 335 ◽  
pp. 361-392 ◽  
Author(s):  
CHRISTOPHER DAVIES ◽  
PETER W. CARPENTER
Keyword(s):  
Numerical Simulation ◽  
Laminar Flow ◽  
Stokes Equations ◽  
Plane Channel ◽  
Solution Procedure ◽  
Good Prospect ◽  
Flow Perturbation ◽  
Compliant Wall ◽  
Compliant Walls ◽  
Tollmien Schlichting

The evolution of two-dimensional Tollmien–Schlichting waves propagating along a wall shear layer as it passes over a compliant panel of finite length is investigated by means of numerical simulation. It is shown that the interaction of such waves with the edges of the panel can lead to complex patterns of behaviour. The behaviour of the Tollmien–Schlichting waves in this situation, particularly the effect on their growth rate, is pertinent to the practical application of compliant walls for the delay of laminar–turbulent transition. If compliant panels could be made sufficiently short whilst retaining the capability to stabilize Tollmien–Schlichting waves, there is a good prospect that multiple-panel compliant walls could be used to maintain laminar flow at indefinitely high Reynolds numbers.We consider a model problem whereby a section of a plane channel is replaced with a compliant panel. A growing Tollmien–Schlichting wave is then introduced into the plane, rigid-walled, channel flow upstream of the compliant panel. The results obtained are very encouraging from the viewpoint of laminar-flow control. They indicate that compliant panels as short as a single Tollmien–Schlichting wavelength can have a strong stabilizing effect. In some cases the passage of the Tollmien–Schlichting wave over the panel edges leads to the excitation of stable flow-induced surface waves. The presence of these additional waves does not appear to be associated with any adverse effect on the stability of the Tollmien–Schlichting waves. Except very near the panel edges the panel response and flow perturbation can be represented by a superposition of the Tollmien–Schlichting wave and two other eigenmodes of the coupled Orr–Sommerfeld/compliant-wall eigensystem.The numerical scheme employed for the simulations is derived from a novel vorticity–velocity formulation of the linearized Navier–Stokes equations and uses a mixed finite-difference/spectral spatial discretization. This approach facilitated the development of a highly efficient solution procedure. Problems with numerical stability were overcome by combining the inertias of the compliant wall and fluid when imposing the boundary conditions. This allowed the interactively coupled fluid and wall motions to be computed without any prior restriction on the form taken by the disturbances.

Implicit Partitioned Fluid-Structure Interaction Coupling

2006 ◽  
Author(s):  
Michael Scha¨fer ◽  
Saim Yigit ◽  
Marcus Heck
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Finite Element ◽  
Fluid Structure Interaction ◽  
Solution Procedure ◽  
Volume Flow ◽  
Fluid Structure ◽  
Flow Solver ◽  
Solution Approach ◽  
Structure Interaction

The paper deals with an implicit partitioned solution approach for the numerical simulation of fluid-structure interaction problems. The solution procedure involves the finite-volume flow solver FASTEST, the finite-element structural solver FEAP, and the coupling interface MpCCI. The method is verified and validated by comparisons with benchmark results and experimental data. Investigations concerning the influence of the grid movement technique and an underrelaxation on the performance of the method are presented.

Numerical Simulation of Residual Stress Field Induced by Water-Jet Cavitation Peening

2013 ◽  
Vol 345 ◽  
pp. 312-315 ◽  
Author(s):  
Bing Han ◽  
Yan Hua Wang ◽  
Chang Liang Xu
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Stress Field ◽  
New Technology ◽  
Diffraction Method ◽  
Spring Steel ◽  
Water Jet ◽  
Material Surface ◽  
Residual Stress Field ◽  
Element Analysis

Water-jet cavitation peening is a new technology for surface modification of metallic materials. Compress residual stress layer is induced by impact wave pressure in the submerged cavitating jets processing. Based on ANSYS/LS-DYNA finite element analysis software, residual stress field in the SAE1070 spring steel material surface induced by cavitate-jet water peening process is simulated, the magnitude and variation rules of the residual stress along the layer depth under different conditions is obtained. In order to verify the correctness of the numerical simulation, the size and distribution of residual stress by the X-ray diffraction method. The results show that the numerical simulation and experimental results are well consistent.

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