Flow in a Toroidal Thermosyphon with Angular Displacement of Heated and Cooled Sections

1979 ◽  
Vol 101 (4) ◽  
pp. 672-676 ◽  
Author(s):  
P. S. Damerell ◽  
R. J. Schoenhals
Keyword(s):  
Steady State ◽  
Reverse Flow ◽  
Angular Displacement ◽  
Vertical Plane ◽  
Steady Condition ◽  
Steady State Flow ◽  
Flow Rates ◽  
Flow Phenomenon ◽  
Angular Displacements ◽  
Good Agreement

A toroidal thermosyphon consisting of a fluid-filled torus located in a vertical plane was studied analytically and experimentally. Good agreement was obtained between analytical predictions and measurements for large values of the angular displacement of the heated and cooled sections. For smaller angular displacements, the analytical predictions of steady state flow rates were found to exceed the corresponding experimentally observed values. The discrepancies were attributed to a reverse flow phenomenon. Some analytically predicted flows were not physically achievable. In these situations the flow would either reach a steady condition in the opposite direction, or it would oscillate indefinitely.

THE FLOW OF GASES THROUGH MICROPOROUS CARBON

1965 ◽  
Vol 43 (7) ◽  
pp. 1968-1972 ◽  
Author(s):  
R. F. Bartholemew ◽  
E. A. Flood
Keyword(s):  
Steady State ◽  
Room Temperature ◽  
Microporous Carbon ◽  
Steady State Flow ◽  
Flow Rates ◽  
State Flow

Steady state flow rates are reported for He, Ar, N2, Kr, methane, propane, and n-butane flowing through a microporous carbon rod at room temperature.

On One Class of Boundary Value Problems of the Steady-State Filtration Theory in Porous Grounds

2014 ◽  
Vol 1020 ◽  
pp. 367-372
Author(s):  
Suren M. Mkhitaryan ◽  
H.V. Tokmajyan
Keyword(s):  
Steady State ◽  
Boundary Value Problems ◽  
Boundary Value ◽  
Filtration Theory ◽  
Steady State Flow ◽  
Fluid Filtration ◽  
Flow Rates ◽  
Piecewise Constant ◽  
Coefficient Of Filtration ◽  
The Ideal

:In the framework of Darcy's law of filtration the investigation results of one class of boundary value problems of the steady-state filtration theory in porous ground base are presented. The plane mixed bounadry value problems on the structural analysis of hydrotechnical con­struction of dam type on filtrating ground base in the form of a layer of finite or infinite thickness are considered. The coefficient of filtration is assumed to be constant, piecewise constant, or changing by the depth of base according to the exponential law, the property of anisotropy of filtration is also taken into account. Axis-symmetric and three-dimentional boundary value problems of the theory of steady-state fluid filtration in a three-dimentional layer of a finite or infinite thickness are discussed. These problems are of the type of Lamb well-known hydrodynamic problems in the theory of steady-state flow of the ideal fluid, when through the circular or rectangular openeing of a rigid screen on the upper bound of the layer the liquid with a definite vertical velocity or with a definite pressure is injected into porous ground base. Here, the fields of velocities and pressures in the layer, as well as flow rates of liquid through the certain sections of the ground base are determined.

Aerodynamic Characteristics of Tracheostomy Speaking Valves

1993 ◽  
Vol 36 (3) ◽  
pp. 529-532 ◽  
Author(s):  
Lisa Fornataro-Clerici ◽  
David J. Zajac
Keyword(s):  
Steady State ◽  
Speech Production ◽  
Clinical Significance ◽  
Tracheostomy Tube ◽  
Flow Characteristics ◽  
Aerodynamic Characteristics ◽  
Future Research ◽  
Steady State Flow ◽  
Upper Airways ◽  
Flow Rates

Pressure-flow characteristics were determined for four different one-way valves used for speech production in the patient who has had a tracheotomy. Each valve was tested at steady-state flow rates of 150, 250, 350, and 450 ml/sec in isolation and attached to a tracheostomy tube. Results indicated significant differences in resistance among the valves. The resistance of one valve was substantially greater than that of the normal upper airways. It is suggested that future research determine the clinical significance, if any, of these differences relative to speech and respiratory behaviors in tracheostomized patients.

scholarly journals Experimental and Computational Study of a Radial Compressor Inlet

1995 ◽  
Author(s):  
Jay M. Koch ◽  
Peter N. Chow ◽  
Brad R. Hutchinson ◽  
Steve R. Elias
Keyword(s):  
Computational Study ◽  
Reverse Flow ◽  
Field Measurements ◽  
Scale Model ◽  
Navier Stokes ◽  
Cfd Analysis ◽  
Flow Rates ◽  
Radial Compressor ◽  
Compressor Inlet ◽  
Good Agreement

Flow field measurements and flow visualization for a quarter scale model of a radial compressor inlet are presented for varying flow rates and inlet profiles. Non-uniform inlet profiles are created using a 90° bend directly upstream of the inlet. Experimental results are compared with the CFD analysis from a commercial 3-D Navier Stokes code. The experimental and computational results show good agreement, even in regions of reverse flow. The results from this study show CFD analysis can be used with confidence to predict the performance of radial compressor inlets.

scholarly journals Steady-state modelling and performance of a rotary direct drive digital valve

2020 ◽  
Vol 53 (3-4) ◽  
pp. 311-319
Author(s):  
Yuesong Li
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Angular Displacement ◽  
Stepper Motor ◽  
Direct Drive ◽  
Rotary Valve ◽  
Steady State Flow ◽  
Load Pressure ◽  
State Flow ◽  
The Relationship

A rotary direct drive digital valve driven by a stepper motor was proposed. By analysing its working principle, the steady-state mathematical model reflecting the relationship between the pressure, the flow and the angular displacement was deduced. Based on this mathematical model, the models of the null valve coefficients, the zero leakage flow and the steady-state flow torque were given. The simulation shows that the relationship between the pressure and the flow of the rotary valve is nonlinear; however, under a constant load pressure, the flow characteristics and the steady-state flow torque characteristics of the rotary valve with rectangular throttle orifices are linear. The experimental results show that the flow is directly proportional to the steps of the stepper motor, and the proposed mathematical models are valid.

Calibration 7" – Cutthroat Flume as New Size for Discharge Measurement at Free Flow Condition

2020 ◽  
Vol 38 (12A) ◽  
pp. 1783-1789
Author(s):  
Jaafar S. Matooq ◽  
Muna J. Ibraheem
Keyword(s):  
Steady State ◽  
Flow Condition ◽  
Laboratory Experiments ◽  
Free Flow ◽  
Experimental Program ◽  
Steady State Flow ◽  
Empirical Formulas ◽  
State Flow ◽  
Operation Conditions ◽  
Throat Width

 This paper aims to conduct a series of laboratory experiments in case of steady-state flow for the new size 7 ̋ throat width (not presented before) of the cutthroat flume. For this size, five different lengths were adopted 0.535, 0.46, 0.40, 0.325 and 0.27m these lengths were adopted based on the limitations of the available flume. The experimental program has been followed to investigate the hydraulic characteristic and introducing the calibrated formula for free flow application within the discharge ranged between 0.006 and 0.025 m3/s. The calibration result showed that, under suitable operation conditions, the suggested empirical formulas can accurately predict the values of discharge within an error ± 3%.

Effect of Viscous Dissipation on MHD Williamson Nanofluid Flow in a Porous Medium

2019 ◽  
Vol 8 (3) ◽  
pp. 5795-5802 ◽  
Keyword(s):  
Porous Medium ◽  
Steady State ◽  
Numerical Solution ◽  
Viscous Dissipation ◽  
Flow Problem ◽  
Numerical Study ◽  
Steady State Flow ◽  
Nanofluid Flow ◽  
Shooting Technique ◽  
Order Four

The main objective of this paper is to focus on a numerical study of viscous dissipation effect on the steady state flow of MHD Williamson nanofluid. A mathematical modeled which resembles the physical flow problem has been developed. By using an appropriate transformation, we converted the system of dimensional PDEs (nonlinear) into coupled dimensionless ODEs. The numerical solution of these modeled ordinary differential equations (ODEs) is achieved by utilizing shooting technique together with Adams-Bashforth Moulton method of order four. Finally, the results of discussed for different parameters through graphs and tables.

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

1996 ◽  
Vol 27 (4) ◽  
pp. 247-254 ◽  
Author(s):  
Zekâi Şen
Keyword(s):  
Steady State ◽  
Graphical Method ◽  
Pumping Test ◽  
Quasi Steady State ◽  
Flow Data ◽  
Steady State Flow ◽  
Storage Coefficient ◽  
State Flow ◽  
Aquifer Test

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

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