On the One-Dimensional Flow Approximation in Sedimentation Processes

2003 ◽  
pp. 127-130 ◽  
Author(s):  
Wilhelm Schneider
Keyword(s):  
One Dimensional ◽  
Dimensional Flow ◽  
Flow Approximation ◽  
The One ◽  
Sedimentation Processes

scholarly journals On the one-dimensional flow of a conducting gas in crossed fields

1961 ◽  
Vol 19 (3) ◽  
pp. 177-193 ◽  
Author(s):  
Erling Dahlberg
Keyword(s):  
One Dimensional ◽  
Dimensional Flow ◽  
The One

Theoretical and Computational Analysis of an Auxiliary Power Unit (APU) Installation Cooling System

2012 ◽  
Author(s):  
Parthiv N. Shah ◽  
Tricia Waniewski Sur ◽  
R. Scott Miskovish ◽  
Albert Robinson
Keyword(s):  
Network Model ◽  
Cooling System ◽  
Dimensional Model ◽  
Ambient Conditions ◽  
Modeling Framework ◽  
Flow Network ◽  
One Dimensional ◽  
Dimensional Flow ◽  
System Pressure ◽  
The One

This paper presents a theoretical one-dimensional model and computational fluid dynamics (CFD) simulations of a tailcone-installed APU cooling system. The work is motivated by the need to deliver sufficient cooling airflow to critical components within an aircraft tailcone compartment. The cooling system considered herein utilizes (1) an eductor system at the APU exhaust and (2) a ram air scoop near an upstream inlet to the compartment to induce the necessary cooling flow during ground and in-flight APU operation. A one-dimensional flow network model provides a framework for the quantification and matching of eductor pumping and system pressure drop characteristics. Detailed CFD models that simulate internal tailcone compartment flows driven by ambient conditions external to the aircraft in ground or flight operation support the one-dimensional model and are used to characterize component performance and assess different scoop and eductor designs. The one-dimensional flow network model is calibrated to the CFD results to predict system cooling performance under known APU loads at points on the ground and in the flight envelope. The agreement between the models is encouraging and suggests the modeling framework and CFD techniques discussed will be applicable to future designs and improvements of eductor-driven aircraft compartment cooling systems.

scholarly journals The one-dimensional flow of a fluid with limited strain-rate

2011 ◽  
Vol 69 (3) ◽  
pp. 549-568 ◽  
Author(s):  
A. Farina ◽  
A. Fasano ◽  
L. Fusi ◽  
K. R. Rajagopal
Keyword(s):  
Strain Rate ◽  
One Dimensional ◽  
Dimensional Flow ◽  
The One

scholarly journals On the convective nature of roll waves instability

2005 ◽  
Vol 2005 (3) ◽  
pp. 259-271 ◽  
Author(s):  
C. Di Cristo ◽  
A. Vacca
Keyword(s):  
Flow Model ◽  
Theoretical Foundation ◽  
Wave Number ◽  
Branch Points ◽  
Periodic Disturbance ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Roll Waves ◽  
The One ◽  
Time Periodic

A theoretical analysis of the Saint-Venant one-dimensional flow model is performed in order to define the nature of its instability. Following the Brigg criterion, the investigation is carried out by examining the branch points singularities of dispersion relation in the complexωandkplanes, whereωandkare the complex pulsation and wave number of the disturbance, respectively. The nature of the linearly unstable conditions of flow is shown to be of convective type, independently of the Froude number value. Starting from this result a linear spatial stability analysis of the one-dimensional flow model is performed, in terms of time asymptotic response to a pointwise time periodic disturbance. The study reveals an influence of the disturbance frequency on the perturbation spatial growth rate, which constitutes the theoretical foundation of semiempirical criteria commonly employed for predicting roll waves occurrence.

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