A theoretical analysis about the effect of aspect ratio on single-phase laminar flow in rectangular ducts

2013 ◽  
Vol 65 ◽  
pp. 1-7 ◽  
Author(s):  
Dianchuan Xing ◽  
Changqi Yan ◽  
Chang Wang ◽  
Licheng Sun
Keyword(s):  
Laminar Flow ◽  
Aspect Ratio ◽  
Theoretical Analysis ◽  
Single Phase

Laminar Flow in a Cylindrical Container With a Rotating Cover

1982 ◽  
Vol 104 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Manlio Bertela` ◽  
Fabio Gori
Keyword(s):  
Laminar Flow ◽  
Aspect Ratio ◽  
Steady Flow ◽  
Reynolds Numbers ◽  
Cylindrical Container ◽  
Cylindrical Chamber ◽  
Flow Rates ◽  
Pressure Fields

Unsteady and steady flow in a cylindrical chamber with a rotating cover has been studied for two Reynolds numbers and three aspect ratio values. The structure of the velocity and pressure fields in the apparatus is described. Primary and secondary volumetric flow rates and torque coefficients are also calculated for all six cases solved.

Simulation By Cellular Automata Of The (Re) Crystallization Of A Matrix Containing An Inert Second Phase

1993 ◽  
Vol 321 ◽  
Author(s):  
C. F. Pezzee ◽  
D. C. Dunand
Keyword(s):  
Aspect Ratio ◽  
Cellular Automata ◽  
Single Phase ◽  
Second Phase ◽  
Particle Fraction ◽  
Aspect Ratios ◽  
Inert Particles ◽  
Mean Size ◽  
Particle Area ◽  
Particle Aspect Ratio

ABSTRACTTwo-dimensional cellular automata simulations were carried out to study the case of the crystallization (or recrystallization) of a matrix containing an inert, immobile second phase. A range of particle area fractions and aspect ratios were investigated under continuous grain nucleation conditions, assuming that the effect of particles is limited to geometric impingement upon contact with the growing grains. Systematic deviations from the classical Johnson, Mehl, Avrami, Kolmogo-rov equation for single-phase materials are observed with increasing particle aspect ratio and particle fraction. Inert particles also influence both mean size and mean aspect ratio of the final grains.

Design-Oriented Analysis of Slow-Scale Bifurcations in Single Phase DC–AC Inverters via Autonomous Transformation Approach

2017 ◽  
Vol 27 (06) ◽  
pp. 1750086 ◽  
Author(s):  
Hao Zhang ◽  
Honghui Ding ◽  
Chuanzhi Yi
Keyword(s):  
Theoretical Analysis ◽  
Circuit Design ◽  
Single Phase ◽  
Underlying Mechanism ◽  
System Stability ◽  
Equivalent Model ◽  
Eigenvalue Sensitivity ◽  
Physical Experiments ◽  
Averaged Model ◽  
Theoretical Results

This paper deals with the design-oriented analysis of slow-scale bifurcations in single phase DC–AC inverters. Since DC–AC inverter belongs to a class of nonautonomous piecewise systems with periodic equilibrium orbits, the original averaged model has to be translated into an equivalent autonomous one via a virtual rotating coordinate transformation in order to simplify the theoretical analysis. Based on the virtual equivalent model, eigenvalue sensitivity is used to estimate the effect of the important parameters on the system stability. Furthermore, theoretical analysis is performed to identify slow-scale bifurcation behaviors by judging in what way the eigenvalue loci of the Jacobian matrix move under the variation of some important parameters. In particular, the underlying mechanism of the slow-scale unstable phenomenon is uncovered and discussed thoroughly. In addition, some behavior boundaries are given in the parameter space, which are suitable for optimizing the circuit design. Finally, physical experiments are performed to verify the above theoretical results.

scholarly journals Nonlinear Control of Single-Phase Shunt Active Power filter Theoretical analysis of closed-loop performances

2011 ◽  
Vol 44 (1) ◽  
pp. 4954-4959 ◽  
Author(s):  
I. Lachkar ◽  
F. Giri ◽  
A. Abouloifa ◽  
J.M. Guerrero ◽  
R. Grino ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Nonlinear Control ◽  
Single Phase ◽  
Closed Loop ◽  
Active Power Filter ◽  
Active Power ◽  
Shunt Active Power Filter ◽  
Power Filter

Improved Correlations for Counting the Effect of Natural Convection on Laminar Flow of Nanofluids

2013 ◽  
Author(s):  
Si-pu Guo ◽  
Zhao-zan Feng ◽  
Ze-cong Fang ◽  
Wei Li ◽  
Jin-liang Xu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Convection ◽  
Laminar Flow ◽  
Prandtl Number ◽  
Single Phase ◽  
Colloidal Suspensions ◽  
Horizontal Tube ◽  
Laminar Mixed Convection ◽  
Wide Range ◽  
Phase Fluid

Nanofluids are colloidal suspensions of nano-scale particles in water, or other base fluids. In this paper, the effect of natural convection on laminar flow of nanofluids in a horizontal tube has been addressed. The obtained experimental data could not be reconciled with existing correlations over a wide range of Prandtl number under laminar mixed convection. Three improved correlations have been derived by using single-phase fluid approach. These correlations fit our data to within ± 10 % and also agree with the data in literature quite well. Such results verify that nanofluids can be treated as a homogeneous mixture with effective thermophysical properties. Utimately, the new correlations have grasped the essence of natural convection and can reduce to both normal forced convection and pure natural convection equations at limiting cases.

scholarly journals Variation of Pressure Drop along the Straight and Bifurcated Channel: Experiment and Simulation

2019 ◽  
Vol 8 (12) ◽  
pp. 2728-2731
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Aspect Ratio ◽  
Computational Model ◽  
Flow Rate ◽  
Normal Water ◽  
Flow Through ◽  
Experiment And Simulation

This paper derives an experimental and simulated investigation carried to analyze the performance of channel for calculating the pressure drop in laminar flow through rectangular shaped (straight and branched) microchannels. The microchannels taken ranged in variable aspect ratio from 0.75 to 1. Every check piece was made from copper and contained only one channel along a direction. The experiments were conducted with normal water, with Reynolds range starting from some 720 to 3500. Predictions obtained supported that with the variation in the aspect ratio the properties of the fluid also change. It is observed that the pressure drop changes with the change in the aspect ratio and flow rate and found that there is a correlation between the experimental and computational model results.

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