Numerical Investigation of the Thermal Behavior in a Hydrogen Tank During Fast Filling Process

2011 ◽  
Author(s):  
Youhei Takagi ◽  
Naoya Sugie ◽  
Kazuhiro Takeda ◽  
Yasunori Okano ◽  
Tooru Eguchi ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Hydrogen Gas ◽  
Tank Wall ◽  
Filling Process ◽  
Adiabatic Wall ◽  
Buoyant Force ◽  
One Dimensional ◽  
Dimensional Simulation

To investigate the thermal behavior during fast hydrogen filling process, the simple one-dimensional analysis considering the heat conduction in tank wall and the three-dimensional numerical simulation dealing with inner gas region were carried out. The numerical analyses were subject to the fast filling test of 35 MPa hydrogen gas into 34 litter tank for 80 seconds. The one-dimensional analysis predicted the temperature rise and the heat loss into surrounding air qualitatively and the averaged temperature of tank wall was underestimated. On the other hand, the three-dimensional simulation overestimated the temperature distribution because of using adiabatic wall condition. However, the effects of buoyant force and convective flow on local thermal profile were fully explained from our numerical results.

Analysis of the Exit Flow Angle and Characteristics of Flow in Axial Turbine Cascades

2020 ◽  
Author(s):  
Narmin B. Hushmandi ◽  
Per Askebjer ◽  
Magnus Genrup
Keyword(s):  
Dimensional Analysis ◽  
Three Dimensional ◽  
Flow Coefficient ◽  
Reference Plane ◽  
Exit Angle ◽  
Design Work ◽  
Flow Angle ◽  
Axial Turbine ◽  
One Dimensional ◽  
The One

Abstract Despite a wealth of sophisticated CFD-methods, most designs are still based on one-dimensional and two-dimensional inviscid analytical tools. In such methods, realistic loss and angle assessment are indeed critical in order to arrive at correct loading, flow coefficient and reaction. The selected values are normally retained through the detailed design sequence for each iteration. This means that the throat sizing and hence the gauge angle is largely based on the early design work within the through-flow environment. Even one-degree error in angle estimation will turn into a rather large capacity error. For most designs, the exchange rate between capacity and gauge angle is on the order of 3–5 percent, per degree exit angle. In a previous publication, a methodology and equations were presented to assess the exit flow in an axial turbine blade row by Mamaev in Russian nomenclature and the tangential coordinate system. The approach, provided a unified and flow-physics based method for assessing exit angles from the geometry features like gauge angle, uncovered turning and flow features like Laval number, etc. Analysis of those formulas showed good agreement with physical flow pattern in real cascades for sub and transonic blade cascades. In this work, the same basic principal procedure is followed by employing the more international agreed nomenclature of blades such as an axial reference plane and Mach number. In the current work, the one-dimensional analysis results were compared with the three dimensional numerical modelling of a full annulus two-stage turbine. Analysis of the results showed the inherent unsteadiness specially outside the rotor blade cascades, however, comparison of the mass averaged exit angle with the one dimensional analysis showed satisfactory agreement.

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.

scholarly journals Study of one-dimensional cure simulation applicable conditions for thick laminates and its comparison with three-dimensional simulation

2018 ◽  
Vol 25 (6) ◽  
pp. 1197-1204 ◽  
Author(s):  
Mingfa Ren ◽  
Qi Wang ◽  
Jie Cong ◽  
Xin Chang
Keyword(s):  
Computational Cost ◽  
Three Dimensional ◽  
Cure Kinetics ◽  
Transient Heat Conduction ◽  
Material System ◽  
Element Analysis ◽  
One Dimensional ◽  
Dimensional Simulation ◽  
The One ◽  
Three Dimensional Finite Element

AbstractThe comparison of one- and three-dimensional cure simulation of thick thermoset matrix laminates was conducted in this study. The applicable conditions of one-dimensional cure simulation were investigated. The transient heat conduction equation coupled to the cure kinetics was solved numerically using one- and three-dimensional finite element analysis. The evolution of temperature and degree of cure of the laminates during the curing process obtained by the simulation agreed well with the published experimental results. The results indicate that a wider one-dimensional analysis applicable region around the center point will be obtained in the laminate with a higher span-to-thickness ratio and in a less anisotropic material system. In the applicable region, the accuracy of the one-dimensional cure simulation can satisfy the engineering request and save the computational cost. While beyond the region, there is a steep increase in deviation of the one- and three-dimensional simulation results.

Resistance of superconducting-normal interfaces at 0 K

1984 ◽  
Vol 391 (1801) ◽  
pp. 255-268 ◽  
Keyword(s):  
Radiative Transfer ◽  
Dimensional Analysis ◽  
Andreev Reflection ◽  
Three Dimensional ◽  
Linear Variation ◽  
Dimensional Theory ◽  
Milne Problem ◽  
One Dimensional ◽  
Interface Resistance ◽  
Bismuth Content

The model proposed by G. L. Harding, A. B. Pippard and J. R. Tomlinson (Harding, Pippard & Tomlinson, Proc . R . Soc . Lond . A340, 1 (1974)) to explain their observation of an enhanced interface resistance at a junction of copper and lead, when bismuth is added to the lead, is developed into a more satisfactory three-dimensional theory. The model for the resistance at 0 K is shown to resemble the Milne problem in radiative transfer, as treated by Chandrasekhar, but considerably modified by Andreev reflection. The theory predicts a linear variation of resistance with bismuth content, as is not incompatible with the measurements, but the magnitude of the calculated resistance, though considerably less than what was found in the original one-dimensional analysis, is still at least 50 % too high. Factors are suggested that should be taken into account in a thorough treatment of the interface, but without any assurance that they would eliminate the discrepancy.

Numerical Project for the Undergraduate Heat Transfer Course

2017 ◽  
Author(s):  
Dani Fadda
Keyword(s):  
Heat Transfer ◽  
Solid Body ◽  
Three Dimensional ◽  
Engineering Curriculum ◽  
One Dimensional ◽  
Conduction Heat Transfer ◽  
Heat Transfer Simulation ◽  
The Difference ◽  
Dimensional Simulation ◽  
Classroom Time

A numerical simulation project, described in this paper, was assigned in an undergraduate heat transfer course in the mechanical engineering curriculum. This project complemented the heat transfer lecture course and its corresponding heat transfer lab. It was used to help students visualize and better understand the difference between conduction heat transfer which occurs within a three-dimensional solid body and the convection and/or radiation which occur at the surface of the solid body. It also allowed the students to generate and compare results of one dimensional heat transfer calculations to three dimensional simulation results. The project contained well defined deliverables and an open-ended deliverable which allowed students to be creative. It gave the students reason to discuss the course outside the classroom. It allowed students to use SolidWorks heat transfer simulation and manage a MATLAB script without taking classroom time. It was appreciated and enjoyed by the students.

scholarly journals EMITTANCE LIMITATION OF A CONDITIONED BEAM IN A STRONG FOCUSING FEL UNDULATOR

2007 ◽  
Vol 22 (22) ◽  
pp. 3826-3837 ◽  
Author(s):  
Z. HUANG ◽  
G. STUPAKOV ◽  
S. REICHE
Keyword(s):  
Electron Beam ◽  
Free Electron ◽  
Free Electron Laser ◽  
Three Dimensional ◽  
Complete Elimination ◽  
Dimensional Model ◽  
Simulation Code ◽  
One Dimensional ◽  
Strong Focusing ◽  
Dimensional Simulation

Various methods have been proposed to condition an electron beam in order to reduce its emittance effect and to improve the short-wavelength free electron laser (FEL) performance. In this paper, we show that beam conditioning does not result in a complete elimination of the emittance effect in an alternating-gradient focusing FEL undulator. Using a one-dimensional model and a three-dimensional simulation code, we derive a criteria for the emittance limitation of a perfectly conditioned beam that depends on the focusing structure.

Development of a zero-dimensional turbulence model for a spark ignition engine

2018 ◽  
Vol 20 (4) ◽  
pp. 441-451 ◽  
Author(s):  
Namho Kim ◽  
Insuk Ko ◽  
Kyoungdoug Min
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Length Scale ◽  
One Dimensional ◽  
Simulation Results ◽  
Dimensional Simulation

The necessity for the use of one-dimensional simulation is growing because cost and time required for hardware optimization and optimal calibration of engines based on experiment are increasing dramatically as engines are equipped with growing numbers of technologies. For one-dimensional simulation results to be more reliable, the accuracy and applicability of the combustion model of a one-dimensional simulation tool must be guaranteed. Because the combustion process in a spark ignition engine is driven by the turbulence, many of existing models focus on the prediction of mean turbulence intensity. Although many successes in the previous models can be found, the previous models contain a large number of adjustable constants or require information supplemented from three-dimensional computational fluid dynamics simulation results. For improved applicability of a model, the number of adjustable constants and inputs to the model must be kept as small as possible. Thus, in this study, a new zero-dimensional (0D) turbulence model was proposed that requires information on the basic characteristics of the engine geometry and has only one adjustable constant. The model was developed based on the energy cascade model with additional consideration of following aspects: loss of kinetic energy during the intake stroke, the effect of piston motion during the compression and the expansion stroke, modifications to correlations for integral length scale, geometric length scale, and production rate of turbulent kinetic energy. An adjustable constant to consider engine design which determines tumble strength was also introduced. The comparison of the simulation results with those of three-dimensional computational fluid dynamics confirmed that the developed model can predict the mean turbulence intensity without case-dependent adjustment of the model constant.

scholarly journals A coupled thermo-hydro-mechanical finite element formulation of one-dimensional beam elements for three-dimensional analysis

2018 ◽  
Vol 104 ◽  
pp. 29-41 ◽  
Author(s):  
Klementyna A. Gawecka ◽  
David M. Potts ◽  
Wenjie Cui ◽  
David M.G. Taborda ◽  
Lidija Zdravković
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
One Dimensional ◽  
Beam Elements
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