Sensitivity Analysis of the Wall Shear Model to the Correlations for Frequency and Slug Holdup in the Gas-Liquid Slug Flow in Pipes

2015 ◽  
Vol 1104 ◽  
pp. 61-67
Author(s):  
Luiz Eduardo Melo Lima ◽  
Eugênio Spanó Rosa
Keyword(s):  
Sensitivity Analysis ◽  
Mixture Model ◽  
Liquid Mixture ◽  
Shear Model ◽  
One Dimensional ◽  
Intermittent Behavior ◽  
Wall Shear ◽  
The One ◽  
Isothermal Gas ◽  
Liquid Flows

The one-dimensional mixture model efficiently predicts gas-liquid flows dominated by gravity force. The advantages of the mixture model are the absence of interfacial terms and the reduced number of transport equations, but its weakness lies on the constitutive laws to predict the wall shear force of a gas-liquid mixture. The objective of this work is to realize a sensitivity analysis of the wall shear model (based on the intermittent behavior of the gas and liquid structures) to the correlations for frequency and slug holdup in the one-dimensional, steady state mixture model applied to an isothermal gas-liquid mixture flowing in the slug regime. The numerical results for the pressure gradient obtained here are compared against experimental data from previous work.

Modeling Transient Churn-Annular Flows in a Long Vertical Pipe

2013 ◽  
Author(s):  
M. V. C. Alves ◽  
J. R. Barbosa ◽  
P. J. Waltrich ◽  
G. Falcone
Keyword(s):  
Annular Flow ◽  
Large Scale ◽  
Coefficient Matrix ◽  
Vertical Tube ◽  
Flow Conditions ◽  
Vertical Pipe ◽  
One Dimensional ◽  
The One ◽  
Energy Equations ◽  
Liquid Flows

A mathematical model is presented to describe the behavior of transient gas-liquid flows involving the churn and annular flow patterns in a long vertical tube. The HyTAF (Hyperbolic Transient Annular Flow) code, developed specifically for this study, is based on the one-dimensional multi-fluid formulation and takes account of hydrodynamic non-equilibrium flow conditions by means of relationships for the rates of droplet entrainment and deposition. A finite difference algorithm is employed to solve the hyperbolic system of mass, momentum and energy equations via the Split Coefficient Matrix Method. The modeling results are compared with experimental data for steady-state annular and churn flows obtained from the literature and with pressure and flow rate induced transient churn-annular flow data generated in a large scale facility (48-mm ID, 42-m long test section).

A Global Multidimensional Sensitivity Analysis of Electronic Systems Subjected to Time-Dependent Excitations

1998 ◽  
Vol 120 (4) ◽  
pp. 391-394
Author(s):  
H. A. Jensen ◽  
A. O. Cifuentes
Keyword(s):  
Sensitivity Analysis ◽  
Technical Note ◽  
Previous Method ◽  
Design Parameters ◽  
Electronic Systems ◽  
Analysis Method ◽  
Electronic Components ◽  
One Dimensional ◽  
Sensitivity Analysis Method ◽  
The One

This technical note presents a global sensitivity analysis method for the dynamic response of electronic systems considering several design parameters at the same time. The method is an extension of a previous method presented by the authors for the one-dimensional case (only one design variable at a time was considered subjected to uncertainty). The method is expected to be useful in the design, analysis and qualification of electronic components.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

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