An Experimental and Analytical Study of Vortex-Flow Temperature Separation by Superposition of Spiral and Axial Flow: Part 2

1959 ◽  
Vol 81 (3) ◽  
pp. 213-221 ◽  
Author(s):  
J. E. Lay
Keyword(s):  
Analytical Study ◽  
Vortex Motion ◽  
Axial Flow ◽  
Experimental Program ◽  
Stagnation Temperature ◽  
Spiral Flow ◽  
Free Vortex ◽  
Temperature Separation ◽  
Flow Part

Part 2 reports on the analytical study. The free vortex motion of the gas upon entrance to the tube is mathematically superposed to a compressible sink to give a spiral flow in the plane. The characteristic existence of limit circles is corroborated by the experimental flow visualization. The solution in space is obtained by addition of a uniform axial velocity to the spiral flow. When viscosity effects are considered, the free vortex is shown to change into a forced vortex. The latter flow is one of minimum kinetic energy and maximum entropy. Energy considerations enable the determination of an optimum cold air radius to give largest stagnation temperature separation. Significantly, this was the radius that gave best performance in the experimental program.

An Experimental and Analytical Study of Vortex-Flow Temperature Separation by Superposition of Spiral and Axial Flows: Part 1

1959 ◽  
Vol 81 (3) ◽  
pp. 202-211 ◽  
Author(s):  
J. E. Lay
Keyword(s):  
Analytical Study ◽  
Vortex Flow ◽  
Vortex Tube ◽  
Radial Distance ◽  
Sink Strength ◽  
Stagnation Temperature ◽  
Spiral Flow ◽  
Temperature Separation ◽  
Forced Vortex ◽  
Potential Vortex

This paper reports on an experimental and analytical study of compressible flow in a uniflow vortex tube. Part 1 deals with an experimental study, Part 2 with the analytical study. Its purpose is to provide a better understanding of the separation of a gas stream into regions of high and low stagnation temperatures, there being at present little agreement as to the theory of operation. The problem is first approached from the experimental standpoint. A large, multipurpose vortex tube is so designed and built that pressure, temperature, and velocity traverses can be taken at six different stations throughout the length of the tube. Pressure, temperature, and velocity traverses are taken by means of hypodermic probes. Velocities are checked by means of a miniature hot-wire anemometer. Data are taken for different runs of inlet pressures and plotted against radial distance. Flow visualization is obtained by means of liquid injection. The analytical study consists of using superposition for the solution of the flow equations. It begins with potential vortex flow in the plane. The solution of this flow is characterized by the existence of sonic or limit circles. Superposition of a sink flow to the vortex solution yields a spiral flow in the plane. The general solution in space is obtained by addition of a uniform axial velocity to the spiral flow. When viscosity effects are considered, the potential vortex changes into a forced vortex, and the solution becomes a superposition of a viscous compressible sink to a forced vortex. Performance or stagnation temperature separation is expressed as function of the ratio of vortex strength to sink strength.

Dynamics of Slender Tapered Beams With Internal or External Axial Flow—Part 2: Experiments

1979 ◽  
Vol 46 (1) ◽  
pp. 52-57 ◽  
Author(s):  
M. J. Hannoyer ◽  
M. P. Paidoussis
Keyword(s):  
Axial Flow ◽  
Internal Flow ◽  
Quantitative Agreement ◽  
External Flow ◽  
Critical Conditions ◽  
Experimental Program ◽  
Water Tunnel ◽  
Elastic Instabilities ◽  
Theoretical Predictions ◽  
Flow Part

This paper describes the experimental program which was conducted in parallel with the theoretical investigation presented in Part 1 of this study. Experiments were conducted in a special water tunnel with silicone rubber cantilevers which, in the case of external flow, were truncated cones, the free ends of which were streamlined; in the case of internal flow the beams were tubular, conical inside, and either conical or cylindrical outside, immersed either in still air or water. Experiments were also conducted with uniform tubular cylinders, and some with simultaneous internal and external axial flow. Qualitatively these experiments support theoretical predictions very well. The critical conditions for the various fluid-elastic instabilities which these systems can develop were measured and compared with theory. Quantitative agreement ranged from excellent to fair, the former for internal flow in conical tubes, and the latter for very slender cones in external flow.

scholarly journals Relationship between Body Mass Index and Tooth Decay in a Population of 3–6-Year-Old Children in Iran

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Leila Shafie Bafti ◽  
Maryam Alsadat Hashemipour ◽  
Hamidreza Poureslami ◽  
Zeinab Hoseinian
Keyword(s):  
Body Weight ◽  
Analytical Study ◽  
Deciduous Teeth ◽  
Tooth Decay ◽  
Cross Sectional ◽  
Dmft Index ◽  
The Mean ◽  
Iranian Children ◽  
The Relationship

The aim of the present study was to evaluate the relationship between BMI and tooth decay in a population of Iranian children. In this cross-sectional descriptive/analytical study, 1482 children were selected from kindergartens and preschool centers in Kerman, Iran. The children underwent examination of deciduous teeth (using the dmft index) after determination of height and weight for calculation of BMI. The relationship between BMI (after adjustment for age) and dmft was determined using Poisson’s regression model. The mean of dmft in children with normal BMI was 1.5-fold that in subjects with extra body weight. Age had a significant effect on dmft. In addition, dmft was higher in boys compared to girls. The results of the present study showed that caries rate in the deciduous teeth of 3–6-year-old children decreases with an increase in body weight.

Direct Determination of the Velocity of Vortices in High-Tc Superconductors by a Non-Equilibrium Method

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3288-3291
Author(s):  
I. Kirschner ◽  
R. Laiho ◽  
A. C. Bódi ◽  
E. Lähderanta ◽  
I. Vajda
Keyword(s):  
Magnetic Field ◽  
Temperature Gradient ◽  
Vortex Motion ◽  
Direct Determination ◽  
Field Investigation ◽  
High Tc Superconductors ◽  
High Tc ◽  
Pinning Centers ◽  
Non Equilibrium

As is shown, thermally assisted vortex motion can come into being in high-T c superconductors due to the applied temperature gradient. Its behavior strongly depends on the local and global microstructure of the samples, moreover on the temperature and magnetic field. Investigation of the density, size and intensity of the pinning centers of specimens leads to the conclusion that the higher homogeneity immediately weakens and the lower one strenghtens the pinning, thus the former promotes and the latter impedes the vortex motion. The non-equilibrium experimental technique together with a.c. susceptibility measurements render possible the direct determination of the velocity of vortices. Depending on the actual microstructural state of samples it has the values between 6 × 10-2 mm/s and 18 × 10-2 mm/s in the case of Y-Ba-Cu-O specimens investigated.

scholarly journals SUBSTANTIATION OF THE FORM AND DETERMINATION OF THE CONSTRUCTIVE PARAMETERS OF THE ROTATION ROLLER OF SOIL

2018 ◽  
Vol 13 (3) ◽  
pp. 72-76
Author(s):  
Гумар Булгариев ◽  
Gumar Bulgariev ◽  
Геннадий Пикмуллин ◽  
Gennadiy Pikmullin ◽  
Ильгиз Галиев ◽  
...  
Keyword(s):  
Analytical Study ◽  
Point Of View ◽  
Design Parameters ◽  
Industrial Complex ◽  
Stage Of Development ◽  
Pass Through ◽  
Spiral Plate ◽  
Working Device ◽  
Important Design

At the present stage of development of the country’s agro-industrial complex, the technological process of surface tillage by combined soil-cultivating machines, simultaneously combining a number of operations in one pass through the field, causes the presence in their designs of the necessary set of various promising working organs. In view of the foregoing, a rotary soil ripper with a spiral-plate working member equipped with radially directed teeth and connected by means of rods with end flanges has been developed. Also, the researched ripper has the limits of penetration of the working element in the form of flat discs equipped with flanges and the radial stop have the ability to rotate around their axes independently of the ripper shaft. An analytical study of the working units of this ripper was carried out from the point of view of the influence of their size and teeth on the process of interaction with the soil, on the basis of which some of their parameters were determined. In conclusion, it was concluded that the analytical equations obtained allow us to justify the choice of the most important design parameters of the proposed new design and design a toothed rotary working device that reduces to constructive implementation after calculating their basic dimensions.

scholarly journals Techniques to Push and Withdraw Knowledge on Time to Achieve Performance Beyond Expected: An Analytical Study in the Office of the Ministry of Higher Education and Scientific Research

Webology ◽  
2021 ◽  
Vol 18 (Special Issue 04) ◽  
pp. 303-318
Author(s):  
Dr. Sumaya Abbas Majeed Al-Rubaye
Keyword(s):  
Higher Education ◽  
Statistical Analysis ◽  
Analytical Study ◽  
Scientific Research ◽  
Philosophical Analysis ◽  
Good Determination ◽  
Ministry Of Higher Education ◽  
A Performance

The study is based on the idea that for a good determination of the techniques adopted in pushing or withdrawing information and knowledge according to the requirements of the type of decisions and according to the appropriate time will lead to achieving a performance that exceeds the ministry's expectations and outside the familiar and the scheme and on that the researcher used the philosophical analysis and preparation of a questionnaire using the Likert pentagon scale and the adoption of descriptive and statistical analysis of the side results Practical, where I found a correlation and influence between the variables of the study, but it is relatively medium in most of its variables to show the ministry's need to support and enhance the capabilities necessary for workers to obtain knowledge at the specified time for the urgent need for them to accomplish the tasks entrusted to them.

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