A Comparison Study of One-Dimensional Models for Stratified Thermal Storage Tanks

1989 ◽  
Vol 111 (3) ◽  
pp. 204-210 ◽  
Author(s):  
Y. H. Zurigat ◽  
K. J. Maloney ◽  
A. J. Ghajar
Keyword(s):  
Three Dimensional ◽  
Thermal Storage ◽  
Comparison Study ◽  
Storage Tanks ◽  
Factors Affecting ◽  
One Dimensional ◽  
Mixing Parameters ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
The One

A survey of the stratified thermal storage tank one-dimensional models available in the literature has been conducted. Six of these models were tested and compared against the experimental data obtained at our laboratories and from the literature. Although various factors affecting the performance of a stratified tank can be accounted for by the higher order models, i.e. two- and three-dimensional models, the introduction of empirically-based mixing parameters into the one-dimensional models renders them widely applicable and practical in the simulation of energy systems incorporating thermal storage tanks.

Modeling of Combustion in Gasoline Direct Injection Engines for the Optimization of Engine Management System Through Reduction of Three-Dimensional Models to (n × One-Dimensional) Models

2003 ◽  
Vol 125 (3) ◽  
pp. 520-532 ◽  
Author(s):  
P. Emery ◽  
F. Maroteaux ◽  
M. Sorine
Keyword(s):  
Direct Injection ◽  
Three Dimensional ◽  
Gasoline Direct Injection ◽  
Computational Time ◽  
Combustion Model ◽  
Dimensional Model ◽  
One Dimensional ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
The One

Gasoline direct injection (GDI) spark ignition engines may be able to run over a wide range of operating conditions. The GDI process allows combustion with lean mixtures which may lead to improved fuel economy and emissions relative to homogeneous spark ignition (SI) engines. To satisfy the different modes of operation, the tuning of GDI engines requires a large number of engine tests which are time-consuming and very expensive. To reduce the number of tests, a model with a very short computational time to simulate the engines in the whole operating range is needed; therefore the objective of this paper is to present a reduced model to analyze the combustion process in GDI engines, applied to a homogeneous stoichiometric mode. The objective of the model is to reproduce the same tendencies as those obtained by three-dimensional models, but with a reduced computational time. The one-dimensional model is obtained thanks to a reduction methodology based on the geometry of the combustion front computed with three-dimensional models of the KIVA-GSM code, a modified version of KIVA-II code including a CFM combustion model. The model is a set of n one-dimensional equations (i.e., for n rays), taking into account a thin flame front, described with the flamelet assumption. It includes a CFM combustion model and a (k,ε)-model including the mean air motions (swirl and tumble). The results of the one-dimensional model are compared to those obtained by the KIVA IIGSM under different engine conditions. The comparison shows that the one-dimensional model overestimates the maximum cylinder pressure, which has an insignificant effect on the net indicated work per cycle. The results obtained by the numerical simulations are close to those given by the three-dimensional model, with a much reduced computation time.

scholarly journals Analysis of high-rise constructions with the using of three-dimensional models of rods in the finite element program PRINS

2018 ◽  
Vol 33 ◽  
pp. 02033
Author(s):  
Vladimir Agapov
Keyword(s):  
Rectangular Cross Section ◽  
Three Dimensional ◽  
Free Vibrations ◽  
Finite Element Program ◽  
One Dimensional ◽  
Static And Dynamic Analysis ◽  
High Rise ◽  
Element Program ◽  
Dimensional Models ◽  
Three Dimensional Models

The necessity of new approaches to the modeling of rods in the analysis of high-rise constructions is justified. The possibility of the application of the three-dimensional superelements of rods with rectangular cross section for the static and dynamic calculation of the bar and combined structures is considered. The results of the eighteen-story spatial frame free vibrations analysis using both one-dimensional and three-dimensional models of rods are presented. A comparative analysis of the obtained results is carried out and the conclusions on the possibility of three-dimensional superelements application in static and dynamic analysis of high-rise constructions are given on its basis.

Preliminary Ship Design Using One and Two-Dimensional Models

1999 ◽  
Vol 36 (02) ◽  
pp. 102-112
Author(s):  
Michael D. A. Mackney ◽  
Carl T. F. Ross
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Two Dimensional ◽  
One Dimensional ◽  
Dimensional Finite Element ◽  
Dimensional Models ◽  
Support Conditions ◽  
The One ◽  
Three Dimensional Finite Element

Computational studies of hull-superstructure interaction were carried out using one-, two-and three-dimensional finite element analyses. Simplification of the original three-dimensional cases to one- and two-dimensional ones was undertaken to reduce the data preparation and computer solution times in an extensive parametric study. Both the one- and two-dimensional models were evaluated from numerical and experimental studies of the three-dimensional arrangements of hull and superstructure. One-dimensional analysis used a simple beam finite element with appropriately changed sections properties at stations where superstructures existed. Two-dimensional analysis used a four node, first order quadrilateral, isoparametric plane elasticity finite element, with a corresponding increase in the grid domain where the superstructure existed. Changes in the thickness property reflected deck stiffness. This model was essentially a multi-flanged beam with the shear webs representing the hull and superstructure sides, and the flanges representing the decks One-dimensional models consistently and uniformly underestimated the three-dimensional behaviour, but were fast to create and run. Two-dimensional models were also consistent in their assessment, and considerably closer in predicting the actual behaviours. These models took longer to create than the one-dimensional, but ran in very much less time than the refined three-dimensional finite element models Parametric insights were accomplished quickly and effectively with the simplest model and processor, but two-dimensional analyses achieved closer absolute measure of the displacement behaviours. Although only static analysis with simple loading and support conditions were presented, it is believed that similar benefits would be found for other loadings and support conditions. Other engineering components and structures may benefit from similarly judged simplification using one- and two-dimensional models to reduce the time and cost of preliminary design.

Performance study of one-dimensional models for stratified thermal storage tanks

Solar Energy ◽  
1993 ◽  
Vol 50 (2) ◽  
pp. 155-166 ◽  
Author(s):  
E.M. Kleinbach ◽  
W.A. Beckman ◽  
S.A. Klein
Keyword(s):  
Thermal Storage ◽  
Storage Tanks ◽  
Performance Study ◽  
One Dimensional ◽  
Dimensional Models

scholarly journals Three-Dimensional Biomodels: Use of Different Materials for the Surgical Planning in Relation to Two Mandibular Cysts Cases

2020 ◽  
pp. 1-6
Author(s):  
Astigueta José Mariano ◽  
Astigueta José Mariano ◽  
Mendoza Cuello Norbin José ◽  
Benitez Javier Alejandro ◽  
Attaguile Alberto ◽  
...  
Keyword(s):  
Surgical Planning ◽  
Postoperative Morbidity ◽  
Three Dimensional ◽  
Surgical Time ◽  
Pathological Fractures ◽  
Dentigerous Cysts ◽  
3D Printers ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
The One

Introduction: The use of three-dimensional models in the diagnosis, planification and treatment of the maxillofacial area pathology has been included in publications since 1980, and has enabled to minimize surgical time, reducing peri and postoperative morbidity, and optimizing surgical results. Currently, the market offers a huge range of 3D printers and materials which allows biomodels to be printed for medical purposes. The purpose of the following paper is to describe the use of two types of three-dimensional models in the therapeutic planning of two cases of mandibular cysts. Case Report: Two cases of mandibular dentigerous cysts are described, in which osteosynthesis plates were used to prevent pathological fractures, pre-modeled together with acrylic positioners on three-dimensional models and printed in different ways. Postoperative clinical and tomographic controls were performed. Conclusion: The knowledge of the properties of the different materials available for the construction of three-dimensional models allows selecting the one that best suits the case needs required, minimizing surgical times and optimizing the results.

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