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.

scholarly journals Josephson oscillations in split one-dimensional Bose gases

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Yuri Daniel van Nieuwkerk ◽  
Jörg Schmiedmayer ◽  
Fabian Essler
Keyword(s):  
Three Dimensional ◽  
Time Dependent ◽  
Dimensional Theory ◽  
Bose Gases ◽  
Microscopic Description ◽  
One Dimensional ◽  
Hartree Fock ◽  
Equilibrium Dynamics ◽  
Self Consistent ◽  
Double Well Potential

We consider the non-equilibrium dynamics of a weakly interacting Bose gas tightly confined to a highly elongated double well potential. We use a self-consistent time-dependent Hartree--Fock approximation in combination with a projection of the full three-dimensional theory to several coupled one-dimensional channels. This allows us to model the time-dependent splitting and phase imprinting of a gas initially confined to a single quasi one-dimensional potential well and obtain a microscopic description of the ensuing damped Josephson oscillations.

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.

Three Dimensional Radiative Transfer in ICON-LEM

2020 ◽  
Author(s):  
Fabian Jakub ◽  
Bernhard Mayer
Keyword(s):  
Radiative Transfer ◽  
Detrimental Effect ◽  
Energy Transport ◽  
Three Dimensional ◽  
Cloud Formation ◽  
One Dimensional ◽  
3D Effects ◽  
Computational Simplicity ◽  
Boundary Layer Dynamics ◽  
Side Illumination

<pre class="moz-quote-pre">Recent studies have shown that the effects of three dimensional radiative transfer may impact cloud formation and precipitation. While one-dimensional solvers are favoured due to their computational simplicity, they do however neglect any horizontal energy transport. In particular, the 1D approximation neglects 3D effects such as cloud side illumination and the displacement of the cloud's shadow at the surface which are relevant whenever the sun is not in the zenith. This has a detrimental effect on the results of high resolution simulations. 3D radiative transfer has the potential to considerably change the boundary layer dynamics, the evolution of clouds, their lifetime and precipitation onset. To this date, studies that investigate the influence of 3D effects on realistic NWP settings are rare, primarily because there haven't been 3D radiative transfer solvers around that were fast enough to be run interactively in a forecast simulation. For that purpose we adapted the TenStream solver (parallel 3D radiative transfer solver for LES) to unstructured meshes and coupled it to ICON-LEM. We will present the new solver in the context of ICON-LEM simulations, the methodologies used and its characteristics.</pre>

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.

scholarly journals Three-dimensional effects in polarization signatures as observed from precipitating clouds by low frequency ground-based microwave radiometers

2006 ◽  
Vol 6 (3) ◽  
pp. 5427-5456
Author(s):  
A. Battaglia ◽  
C. Simmer ◽  
H. Czekala
Keyword(s):  
Radiative Transfer ◽  
Monte Carlo Model ◽  
Three Dimensional ◽  
Low Frequency ◽  
Radiative Transfer Model ◽  
Observation Angle ◽  
Transfer Model ◽  
One Dimensional ◽  
Dimensional Effects ◽  
The Impact

Abstract. Consistent negative polarization differences (i.e. differences between the vertical and the horizontal brightness temperature) are observed when looking at precipitating systems by ground-based radiometers at slant angles. These signatures can be partially explained by one-dimensional radiative transfer computations that include oriented non-spherical raindrops. However some cases are characterized by polarization values that exceed differences expected from one-dimensional radiative transfer. A three-dimensional fully polarized Monte Carlo model has been used to evaluate the impact of the horizontal finiteness of rain shafts with different rain rates at 10, 19, and 30 GHz. The results show that because of the reduced slant optical thickness in finite clouds, the polarization signal can strongly differ from its one-dimensional counterpart. At the higher frequencies and when the radiometer is positioned underneath the cloud, significantly higher negative values for the polarization are found which are also consistent with some observations. When the observation point is located outside of the precipitating cloud, typical polarization patterns (with troughs and peaks) as a function of the observation angle are predicted. An approximate 1-D slant path radiative transfer model is considered as well and results are compared with the full 3-D simulations to investigate whether or not three-dimensional effects can be explained by geometry effects alone. The study has strong relevance for low-frequency passive microwave polarimetric studies.

scholarly journals Reduction of radiation biases by incorporating the missing cloud variability by means of downscaling techniques: a study using the 3-D MoCaRT model

2012 ◽  
Vol 5 (9) ◽  
pp. 2261-2276 ◽  
Author(s):  
S. Gimeno García ◽  
T. Trautmann ◽  
V. Venema
Keyword(s):  
Radiative Transfer ◽  
Spatial Resolution ◽  
Heterogeneous Media ◽  
Monte Carlo Model ◽  
Computational Cost ◽  
Three Dimensional ◽  
Accurate Solution ◽  
Stochastic Methods ◽  
Climate Modelling ◽  
One Dimensional

Abstract. Handling complexity to the smallest detail in atmospheric radiative transfer models is unfeasible in practice. On the one hand, the properties of the interacting medium, i.e., the atmosphere and the surface, are only available at a limited spatial resolution. On the other hand, the computational cost of accurate radiation models accounting for three-dimensional heterogeneous media are prohibitive for some applications, especially for climate modelling and operational remote-sensing algorithms. Hence, it is still common practice to use simplified models for atmospheric radiation applications. Three-dimensional radiation models can deal with complex scenarios providing an accurate solution to the radiative transfer. In contrast, one-dimensional models are computationally more efficient, but introduce biases to the radiation results. With the help of stochastic models that consider the multi-fractal nature of clouds, it is possible to scale cloud properties given at a coarse spatial resolution down to a higher resolution. Performing the radiative transfer within the cloud fields at higher spatial resolution noticeably helps to improve the radiation results. We present a new Monte Carlo model, MoCaRT, that computes the radiative transfer in three-dimensional inhomogeneous atmospheres. The MoCaRT model is validated by comparison with the consensus results of the Intercomparison of Three-Dimensional Radiation Codes (I3RC) project. In the framework of this paper, we aim at characterising cloud heterogeneity effects on radiances and broadband fluxes, namely: the errors due to unresolved variability (the so-called plane parallel homogeneous, PPH, bias) and the errors due to the neglect of transversal photon displacements (independent pixel approximation, IPA, bias). First, we study the effect of the missing cloud variability on reflectivities. We will show that the generation of subscale variability by means of stochastic methods greatly reduce or nearly eliminate the reflectivity biases. Secondly, three-dimensional broadband fluxes in the presence of realistic inhomogeneous cloud fields sampled at high spatial resolutions are calculated and compared to their one-dimensional counterparts at coarser resolutions. We found that one-dimensional calculations at coarsely resolved cloudy atmospheres systematically overestimate broadband reflected and absorbed fluxes and underestimate transmitted ones.

scholarly journals Analysis of the Discrete Theory of Radiative Transfer in the Coupled “Ocean–Atmosphere” System: Current Status, Problems and Development Prospects

2020 ◽  
Vol 8 (3) ◽  
pp. 202 ◽  
Author(s):  
Viktor P. Afanas’ev ◽  
Alexander Yu. Basov ◽  
Vladimir P. Budak ◽  
Dmitry S. Efremenko ◽  
Alexander A. Kokhanovsky
Keyword(s):  
Radiative Transfer ◽  
Three Dimensional ◽  
Operator Method ◽  
Current Status ◽  
One Dimensional ◽  
Current State ◽  
The Matrix ◽  
The One ◽  
Discrete Theory ◽  
Development Prospects

In this paper, we analyze the current state of the discrete theory of radiative transfer. One-dimensional, three-dimensional and stochastic radiative transfer models are considered. It is shown that the discrete theory provides a unique solution to the one-dimensional radiative transfer equation. All approximate solution techniques based on the discrete ordinate formalism can be derived based on the synthetic iterations, the small-angle approximation, and the matrix operator method. The possible directions for the perspective development of radiative transfer are outlined.

Taylor Cylinder Test Reduction Using a One-Dimensional Theory

2008 ◽  
Author(s):  
Rachel Russo ◽  
Bart Baker ◽  
Nicholas Dutton ◽  
Karen Torres ◽  
Stanley E. Jones
Keyword(s):  
Dimensional Analysis ◽  
Test Data ◽  
Impact Test ◽  
True Strain ◽  
True Stress ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Cylinder Test ◽  
Taylor Impact ◽  
The One

A one-dimensional analysis of the Taylor impact test [4] has been used to estimate the quasi-static stress for several different alloys. One criticism of this work was the use of Taylor cylinder test data to estimate the quasi-static true stress/true strain compression diagram. The one-dimensional theory does accommodate this estimate. The purpose of this paper is to demonstrate that this process leads to acceptable results by analyzing a series of high, medium, and low strength materials.

Influence of Rotatory Inertia and Shear on Flexural Motions of Isotropic, Elastic Plates

1951 ◽  
Vol 18 (1) ◽  
pp. 31-38 ◽  
Author(s):  
R. D. Mindlin
Keyword(s):  
Uniqueness Theorem ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Elastic Plates ◽  
Dimensional Theory ◽  
Rotatory Inertia ◽  
One Dimensional ◽  
Edge Conditions

Abstract A two-dimensional theory of flexural motions of isotropic, elastic plates is deduced from the three-dimensional equations of elasticity. The theory includes the effects of rotatory inertia and shear in the same manner as Timoshenko’s one-dimensional theory of bars. Velocities of straight-crested waves are computed and found to agree with those obtained from the three-dimensional theory. A uniqueness theorem reveals that three edge conditions are required.

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