scholarly journals DESIGN AND STUDY OF DIMENSIONAL PARAMETERS INFLUENCE ON VORTEX TUBE BEHAVIOR

2019 ◽  
Vol 18 (2) ◽  
pp. 13
Author(s):  
F. P. Branco ◽  
E. D. Buchelt ◽  
F. M. Barbosa ◽  
B. P. Rosa ◽  
D. J. Laporte
Keyword(s):  
Vortex Tube ◽  
Tube Diameter ◽  
Compressed Air ◽  
Tube Length ◽  
Electronic Systems ◽  
Machining Processes ◽  
Cold Air ◽  
Air Temperatures ◽  
Small Influence ◽  
Dimensional Parameters

Vortex tube is a thermodynamic device, with no moving parts, applied to separate hot and cold air from compressed air injected into the tube. It has many applications in the industry, for example, among others, it can be mentioned electronic systems cooling, machining processes cooling and environmental chambers. This paper presents the design and tube dimensioning based on parameters and data found in the literature. Therefore, a prototype has been made and tested, which allowed the understanding of the influence of internal tube diameter and width on the hot and cold air temperatures while submitted to compressed air with pressure varying from 1 to 2.5bar. Results of tested configurations indicates that the relation between tube length and diameter (L/D) has small influence on vertex tube behavior, meanwhile, 3/8” tube diameter shows lowest temperatures on cold flow (-6.5°C, -8.0°C and -8.5°C) and higher COP (≈ 0.15).

scholarly journals Investigation on the Changes in the Temperature that is Caused in Vortex Tube

2018 ◽  
Vol 1 (1) ◽  
pp. 673-681
Author(s):  
Unal Uysal ◽  
Selahattin Kasar
Keyword(s):  
Low Temperatures ◽  
Vortex Tube ◽  
Air Flow ◽  
Inlet Pressure ◽  
Cold Air ◽  
Air Temperatures ◽  
Cold Mass

This paper presents effect of cold mass friction, the rates of air flow, the inlet pressure, and the time on hot and cold air temperatures that are generated in the vortex tube. The vortex tube is manufactured by simple equip-ments within low prices. That proves the simplification of the vortex tube. Although the efficiency of vortex tube is low, but it produces low temperatures without using expensive cooling machines.

scholarly journals Simulations of a cold-air pool associated with elevated wintertime ozone in the Uintah Basin, Utah

2014 ◽  
Vol 14 (11) ◽  
pp. 15953-16000 ◽  
Author(s):  
E. M. Neemann ◽  
E. T. Crosman ◽  
J. D. Horel ◽  
L. Avey
Keyword(s):  
Boundary Layer ◽  
Snow Cover ◽  
Layer Structure ◽  
Inversion Layer ◽  
Cloud Microphysics ◽  
Photochemical Reactions ◽  
Near Surface ◽  
Cold Air ◽  
Air Temperatures ◽  
Uintah Basin

Abstract. Numerical simulations are used to investigate the meteorological characteristics of the 1–6 February 2013 cold-air pool in the Uintah Basin, Utah, and the resulting high ozone concentrations. Flow features affecting cold-air pools and air quality in the Uintah Basin are studied, including: penetration of clean air into the basin from across the surrounding mountains, elevated easterlies within the inversion layer, and thermally-driven slope and valley flows. The sensitivity of the boundary layer structure to cloud microphysics and snow cover variations are also examined. Ice-dominant clouds enhance cold-air pool strength compared to liquid-dominant clouds by increasing nocturnal cooling and decreasing longwave cloud forcing. Snow cover increases boundary layer stability by enhancing the surface albedo, reducing the absorbed solar insolation at the surface, and lowering near-surface air temperatures. Snow cover also increases ozone levels by enhancing solar radiation available for photochemical reactions.

scholarly journals The second law analysis of natural gas behavior within a vortex tube

2013 ◽  
Vol 17 (4) ◽  
pp. 1079-1092 ◽  
Author(s):  
Mahyar Kargaran ◽  
A. Arabkoohsar ◽  
S.J. Hagighat-Hosini ◽  
V. Farzaneh-Kord ◽  
Mahmood Farzaneh-Gord
Keyword(s):  
Natural Gas ◽  
Entropy Generation ◽  
Vortex Tube ◽  
Tube Length ◽  
Orifice Diameter ◽  
Working Fluid ◽  
Energy Separation ◽  
Second Law ◽  
Gas Streams ◽  
Mass Fractions

Vortex tube is a simple device without a moving part which is capable of separating hot and cold gas streams from a higher pressure inlet gas stream. The mechanism of energy separation has been investigated by several scientists and second law approach has emerged as an important tool for optimizing the vortex tube performance. Here, a thermodynamic model has been used to investigate vortex tube energy separation. Further, a method has been proposed for optimizing the vortex tube based on the rate of entropy generation obtained from experiments. Also, an experimental study has been carried out to investigate the effects of the hot tube length and cold orifice diameter on entropy generation within a vortex tube with natural gas as working fluid. A comparison has been made between air and natural gas as working fluids. The results show that the longest tube generates lowest entropy for NG. For air, it is middle tube which generates lowest entropy. Integration of entropy generation for all available cold mass fractions unveiled that an optimized value for hot tube length and cold orifice diameter is exist.

Rotary Ultrasonic Machining of Basalt Rock Using Compressed Air As Coolant: A Study on Edge Chipping and Surface Roughness

2019 ◽  
Author(s):  
Palamandadige Fernando ◽  
Meng Zhang ◽  
Zhijian Pei ◽  
Adam Owens
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Construction Material ◽  
Compressed Air ◽  
Ultrasonic Power ◽  
Ultrasonic Machining ◽  
Rotary Ultrasonic Machining ◽  
Machining Processes ◽  
Edge Chipping ◽  
Basalt Rock

Abstract The aim of this study is to investigate the edge chipping and surface roughness of basalt rock processed by rotary ultrasonic machining (RUM) using compressed air as coolant. Basalt rock is commonly used as a building and construction material for foundations and dams, as well as in architectural designs such as constructing thin veneers and facades. Rotary ultrasonic machining, a hybrid process of grinding and ultrasonic machining, is employed to drill difficult-to-machine materials such as ceramics, composites, titanium alloys, stainless steel, etc. RUM has many advantages over conventional machining processes such as twist drilling. These advantages include lower cutting force, higher surface quality, lower tool wear, etc. This paper is the first in literature to report a study on edge chipping and surface roughness on RUM of basalt rock using cold compressed air as coolant. The effects of three input variables (tool rotation speed, feedrate, and ultrasonic power) on cutting force, torque, edge chipping, and surface roughness were studied. Experimental results obtained from this investigation show that RUM with cold air as the coolant has the capability to machine holes in basalt rock with a surface roughness of less than 3.5 μm without severe edge chipping.

Vortex Tube Impact on Cooling Milling Machining

2012 ◽  
Author(s):  
Basel Alsayyed ◽  
Mohammad O. Hamdan ◽  
Saud Aldajah
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Vortex Tube ◽  
Compressed Air ◽  
Heat Map ◽  
Milling Operations ◽  
Three Samples ◽  
Cutting Operation ◽  
Water Base ◽  
Vortex Tubes

In this paper, the authors will present the use of a vortex tube in cooling milling operations. The focuses will be regarding the surface finish and temperature of the tool during the cutting operation. Three cooling setups, cutting without coolant, cooling with a water base traditional coolant, and cooling with vortex tube will be compared. A Flir E320 UV camera has been used to capture the heat map around the tool during the cutting process. The surface roughness has been measured and analysed for all three samples using Taylor/Hobson Precision Surtronc 3+ apparatus. The findings of this study have shown comparative efficient cooling using the vortex tubes. The vortex tube cooling is also cleaner and can be directed in such a way to collect the chips as they develop with the least mess or no mess. Vortex tubes have no moving parts, and it is very much maintenance free device. Compressed air is needed to feed the vortex tube, which is available usually in any machine shop.

Determination of Brittle Point of Rubber Materials in Cold Air

1944 ◽  
Vol 17 (3) ◽  
pp. 751-756
Author(s):  
C. K. Chatten ◽  
S. A. Eller ◽  
T. A. Werkenthin
Keyword(s):  
Ambient Air ◽  
Cold Air ◽  
Air Temperatures ◽  
Brittle Point ◽  
Made In

Abstract The method described herein for determining brittle point is relatively simple, and the results are indicative of the ability of the material to withstand impact combined with bending. It is believed that this combination will more correctly evaluate brittle point than a bent loop test or other moderate flexing tests. If the material is exposed to low ambient air temperatures in service, then tests to determine brittle point should be made in cold air and not in an immersion bath. Appreciable differences in brittle point are obtained by judicious modifications in compounding ingredients of Buna-N and chloroprene synthetic rubbers.

Numerical Prediction of Flow Patterns in Bubble Pumps

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Ali Benhmidene ◽  
Bechir Chaouachi ◽  
Mahmoud Bourouis ◽  
Slimane Gabsi
Keyword(s):  
Heat Flux ◽  
Void Fraction ◽  
Liquid Velocity ◽  
Fluid Model ◽  
Flow Patterns ◽  
Heat Fluxes ◽  
Tube Diameter ◽  
Tube Length ◽  
Velocity Versus ◽  
Bubble Pump

In the present study, the ammonia-water mixing flow in a bubble pump is numerically simulated. The flow patterns of a two-phase flow in a bubble pump were studied under different conditions of heat flux and tube diameter. A one-dimensional two-fluid model was developed under constant heat flux. This model was used to predict the variations in void fraction and liquid and vapor velocities throughout the tube. Then, the void fraction profile and the curve of liquid velocity versus vapor velocity were used to predict the flow patterns along the tube length. It was found that at heat fluxes below 15 kW m−2, bubbly, slug, and churn flows are the dominating regimes, and the length of these flow regimes depends on the tube diameter. For heat fluxes higher than 15 kW m−2, the bubble pump operates under the churn and annular regimes, and the bubble pump performance is improved when the tube diameter increases.

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