Finite Element Based Simulation Software Research Articles

Design, Simulation and Fabrication of a U-shaped Antenna Having a Defected Ground for Wide Band Applications

A novel method to develop an Ultra-Wide Band (UWB) antenna is proposed in which a defected ground structure technique is employed. The proposed design is Micro-strip fed slotted patch with an altered ground side. The Operating Band width of antenna is 3.1 GHz to 10.6 GHz. The design parameters of the antenna have been optimized using high frequency finite element based simulation software for the best gain, bandwidth and efficiency performance. Effectively directional radiation patterns and large impedance bandwidth has been observed from simulation results. The design parameters and the simulation results are all reported in this paper including the radiation pattern in different frequencies within the operating band. The proposed antenna is also fabricated and the measurement results are also presented in this paper.

MODAL AND STRUCTURAL ANALYSIS STUDIES OF THE TRANSFER LINE CARRIER CONSTRUCTION

In this study, the analysis studies carried out to assist the design stages of the part transfer line to be used in an automobile factory and the experiences gained from these analysis studies are emphasized. These experiences are very important in similar product developments in industrial design. Design and analysis studies carried out prior to manufacturing ensure that production can be carried out without any problems. For this reason, special importance should be given to the design stages in the process and alternative solutions should be created by revising the design in every aspect. Analysis studies should be carried out to select the best design among these solutions. The finite element approach, which is the approach used by today's special analysis software, was preferred in this study. Many analyses were carried out on the model whose boundary conditions were determined and the real-life behaviour of the design was foreseen. In the analysis studies, modal analyses and structural displacements were carried out in order to understand the dynamic behaviours and the stresses will not exceed certain limits. A finite element based simulation software was used in the analysis studies. Here, the importance of design experiences based on past experiences has emerged in the optimization of the design. The design steps to be presented in the paper and the analysis results obtained through the design were also very useful in the prototype manufacturing phase and the transfer line was safely demonstrated. As a result of the trials, the transfer line was delivered to the customer and still fulfils its duty safely.

Comparative study of phase change phenomenon in high temperature cascade latent heat energy storage system using conduction and conduction-convection models

In the current study, a combined conduction-convection model is developed to analyze the effect of natural convection inside the Phase Change Material (PCM) during melting and solidification processes of a cascade Latent Heat Thermal Energy Storage System (LHTESS) and it is compared with pure conduction model. Effective heat capacity method is employed to simulate the phase change phenomena in both combined model and pure conduction models. Boussinesq approximation is used to predict the effect of natural convection inside the PCM in the combined model. The governing equations involved in the model are solved using finite element based simulation software, COMSOL Multiphysics 4.3a. Parametric study is conducted on charging and discharging processes of cascade LHTESS using both the models. The comparative study between combined model and pure conduction model demonstrated that the pure conduction model under predicts the rate of heat transfer between HTF and PCM at lower inlet velocity of HTF, where natural convection plays a significant role in the phase change phenomena. The deviation between the models decreases with increase in the inlet velocity of HTF for both charging and discharging processes. The simulation results indicated that the heat transfer phenomena inside the PCM become more conduction dominant at higher inlet velocity of HTF. The results also revealed that the inlet temperature of HTF plays a major role in decreasing the charging/ discharging time.

ArbiLoMod, a Simulation Technique Designed for Arbitrary Local Modifications

Engineers manually optimizing a structure using Finite Element based simulation software often employ an iterative approach where in each iteration they change the structure slightly and resimulate. Standard Finite Element based simulation software is usually not well suited for this workflow, as it restarts in each iteration, even for tiny changes. In settings with complex local microstructure, where a fine mesh is required to capture the geometric detail, localized model reduction can improve this workflow. To this end, we introduce ArbiLoMod, a method which allows fast recomputation after arbitrary local modifications. It employs a domain decomposition and a localized form of the Reduced Basis Method for model order reduction. It assumes that the reduced basis on many of the unchanged domains can be reused after a localized change. The reduced model is adapted when necessary, steered by a localized error indicator. The global error introduced by the model order reduction is controlled by a robust and efficient localized a posteriori error estimator, certifying the quality of the result. We demonstrate ArbiLoMod for a coercive, parameterized example with changing structure.

Evaluation of Sheet Forming Simulation for an Integrated Reverse Engineering System

AbstractThis paper presents the method and results for the evaluation of sheet forming simulation software commercially available. The objective of the evaluation is to identify best suitable finite element-based simulation software for an integrated reverse engineering system that supports sheet metal forming at a defense logistics center. This system is composed of a set of software tools and hardware equipment that are seamlessly integrated to support in-house part manufacturing, from design to production. Excellent hardware equipment that supports reverse engineering and sheet forming manufacturing is currently employed at the center. The sheet forming simulation software is one of the major components being added to the system. This software evaluation is conducted entirely from the needs of the center. Simulation capabilities involved in the evaluation include relevant forming operations, such as draw, sheet hydro-forming and stretch forming; as well as die design, and blank nesting. Parts are physi...

An innovative cloak enables arbitrary multi-objects hidden with visions and movements

We propose an innovative cloak to enable arbitrary multi-objects hidden with visions and movements. We develop the cloak with spatially varying constitutive parameters by employing transformation optics with two-step coordinate transformations and testify the performance of the cloak by finite element based simulation software. In simulation, the electric field distributions (Ez) of the cloak for different circumstances agree with the analytical prediction well.

Heat transfer to a canned corn starch dispersion under intermittent agitation

A thermorheological model for the heating a 3.5% corn starch dispersion (STD) was used together with a finite element based simulation software (FIDAP) to solve the governing mass, momentum and energy transport equations for heating the STD at 121 °C in a 303×406 axially rotating can. Heat transfer from the hot wall to the inner canned STD improved considerably in intermittent rotation because the boundary layer region was not covered with a thick layer of gelatinized starch. In comparison to the experimental data obtained in a Steritort™, the simulated time–temperature profile was conservative and was in reasonable agreement. Further, simulation results showed that increase in the retort temperature results in a higher relative volume average temperature. In contrast, increase in the reel rotational speed in the 5–12 rpm range brought about a reduction in the volume average temperature.

Simulation of heat transfer to a canned corn starch dispersion subjected to axial rotation

A finite element based simulation software (FIDAP) was used to solve the governing mass, momentum and energy transport equations for heating a 3.5% corn starch dispersion (STD) at 121°C in a 303×406 axially rotating can. A thermorheological model for the STD was incorporated into the program. Results revealed non-uniform temperature distribution with different slowest heating point (SHP) in the can when it was stationary and continuously rotating at 15 and 146 rpm. At 146 rpm, a highly viscous layer of gelatinized starch that formed at the can wall hindered heat transfer in the radial direction resulting in slower heat penetration than at 0 and 15 rpm.