scholarly journals The Effect of Tube Length, Cold Exit Diameter and Working Gas on The Cold Flow Temperature of Vortex Tube

2018 ◽  
Vol 225 ◽  
pp. 02010
Author(s):  
Muhammad Fadhli Suhaimi ◽  
Mohd Hazwan Yusof ◽  
Mohamad Nor Hafiz Rashid ◽  
Mohamad Firdaus Basrawi
Keyword(s):  
Vortex Tube ◽  
Free Software ◽  
Simple Device ◽  
Tube Length ◽  
Geometrical Parameters ◽  
Flow Temperature ◽  
Cold Flow ◽  
Different Types ◽  
Spot Cooling ◽  
Cold Gas

A vortex tube is a simple device which works as a refrigerator, also known as Ranque Vortex Tube, Hilsch Vortex Tube, and Ranque–Hilsch vortex tube. It is used to obtain desired hot and cold gas and is widely used for spot cooling in industry. In vortex tube, the effect of geometrical parameters on the cold flow temperature of vortex tube is still unclear, and effect of certain working gas is unidentified. Hence, the objective of this analysis is to determine the effect of length of the vortex tube, cold exit diameter and different working gas. 3 different tube lengths, 3 different cold exit diameters, and 8 different types of gas are used. Simflow, which is free software, is selected to analyse the effect numerically. From the results, it is clear that the optimum tube length, cold exit diameter, and working gas are L = 175 mm, d = 4 mm and helium, respectively.

scholarly journals Structural diversity of disc galaxies originating in the cold gas inflow from cosmic webs

2020 ◽  
Vol 494 (1) ◽  
pp. L37-L41
Author(s):  
Masafumi Noguchi
Keyword(s):  
High Redshift ◽  
Morphological Diversity ◽  
Structural Diversity ◽  
High Mass ◽  
Cold Flow ◽  
Hubble Sequence ◽  
The Galaxy ◽  
Gas Accretion ◽  
Disc Galaxies ◽  
Cold Gas

ABSTRACT Disc galaxies show a large morphological diversity with varying contribution of three major structural components: thin discs, thick discs, and central bulges. Dominance of bulges increases with the galaxy mass (Hubble sequence), whereas thick discs are more prominent in lower mass galaxies. Because galaxies grow with the accretion of matter, this observed variety should reflect diversity in accretion history. On the basis of the prediction by the cold-flow theory for galactic gas accretion and inspired by the results of previous studies, we put a hypothesis that associates different accretion modes with different components. Namely, thin discs form as the shock-heated hot gas in high-mass haloes gradually accretes to the central part, thick discs grow by the direct accretion of cold gas from cosmic webs when the halo mass is low, and finally bulges form by the inflow of cold gas through the shock-heated gas in high-redshift massive haloes. We show that this simple hypothesis reproduces the mean observed variation of galaxy morphology with the galaxy mass. This scenario also predicts that thick discs are older and poorer in metals than thin discs, in agreement with the currently available observations.

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.

scholarly journals Monitoring of drilling conditions using the Hilbert-Huang transformation

2018 ◽  
Vol 148 ◽  
pp. 16003 ◽  
Author(s):  
Piotr Wolszczak ◽  
Grzegorz Litak ◽  
Marek Dziuba
Keyword(s):  
Fourier Transform ◽  
Numerical Simulations ◽  
Hilbert Transform ◽  
Geometrical Parameters ◽  
Drilling Process ◽  
Nonlinear Characteristics ◽  
Different Types ◽  
Fourier Spectra ◽  
Backbone Curves ◽  
Drilling Conditions

The article presents the results of design and monitoring the drilling process. Vibroacoustic sensors were used to observe spindle vibrations. These signals were subjected to a Huang decomposition and a Fourier transform. Results for various conditions were studied and classified with help of Fourier spectra and the envelope curves. Using the additional results of numerical simulations sources of vibration were identified. We considered four different types of drilling which were diversified in terms of geometrical parameters of blades. The application of Hilbert transform enable to find nonlinear characteristics via the deflection profile of resonance backbone curves.

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 IMPROVEMENT OF OFFICIAL CHARACTERISTICS OF THE SURFACE LAYER DETAILS BY APPLICATION OF SURFACE PLASTIC DEFORMATION AND GASODYNAMYNAMYNAMINE

2020 ◽  
pp. 90-100
Author(s):  
Viktor Matviychuk ◽  
Oleg Haidamak ◽  
Mykola Kolesnik
Keyword(s):  
Plastic Deformation ◽  
Surface Plastic Deformation ◽  
Cold Gas Dynamic Spraying ◽  
Thin Plates ◽  
Geometrical Parameters ◽  
Surface Plastic ◽  
Gradual Change ◽  
Gas Dynamic ◽  
Multi Stage ◽  
Cold Gas

The article investigates changes in the characteristics of the surface layers of parts processed by methods of surface plastic deformation (SPD). It is shown that at SPD the strength and hardness characteristics of the material increase and residual compression stresses are formed. On the basis of the study of the stress-strain state of the material at the SPD, its non-monotonicity is established, which is manifested in the gradual change of sign of the components of deformations and stresses. In this regard, a tensor-nonlinear damage accumulation model was used to evaluate the deformability of the material, which takes into account the directional nature of the damage and the anisotropy of the plasticity of the deformed metal. Based on this model, an expression was obtained to determine the plasticity resource used in the case of multi-stage SPD. According to the results of the calculations, it is established that the maximum plasticity resource used in the SPD is at a depth of approximately 0.1 of the diameter of the plastic footprint of the tool, and destruction at full exhaustion of the plasticity resource occurs in the form of peeling of thin plates of appropriate thickness. Recommendations for displacement of the most reinforced layers to the surface of the workpiece are developed, as well as recommendations for limiting deformation by the amount of plasticity resource used. The conducted research allows to assign the optimal modes of SPD at the stage of technological process design. A device for cold gas-dynamic spraying was developed and the possibility of creating antifriction sections using it was investigated. Graphs of dependence of geometrical parameters of the deposited layer on the sputtering distance are constructed and methods and schemes of preparation for deposition of the surface of the workpiece using SPD methods are developed. Experimental cold gas-dynamic spraying was carried out and optimal parameters of the process of spraying of antifriction layers of bronze and metal polymers (pressure, and the temperature of the compressed air and the temperature of the workpiece) on the formed roller surface were determined. A new concept of increasing the contact strength and durability of friction pairs is proposed.

scholarly journals Experimental Evaluation of the Energy Performance of an Air Vortex Tube when the Inlet Parameters are Varied

2013 ◽  
Vol 7 (1) ◽  
pp. 98-107 ◽  
Author(s):  
E. Torrella ◽  
J. Patiño ◽  
D. Sánchez ◽  
R. Llopis ◽  
R. Cabello
Keyword(s):  
Vortex Tube ◽  
Experimental Tests ◽  
Energy Performance ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Temperature Variations ◽  
Cold Flow ◽  
Air Inlet ◽  
Cold Stream ◽  
Cooling Tube

The paper presents the analysis of the energy performance of an air vortex cooling tube under variations of the air inlet properties, with three independent experimental tests validated through the energy balance in the device. The experimental analysis includes the following variations of the input conditions: First, the effect of the air inlet pressure to the vortex tube, focused on the analysis of temperature variations in the output cold stream and in the cooling capacity when the cold flow fraction varies. Second, we studied air inlet temperature variations to the vortex tube under different cold flow fractions, which is an analysis not found in the literature. And finally, is studied the performance of the vortex tube when the insulation is provided or in absence of insulation.

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