AN EXPERIMENTAL INVESTIGATION OF THE GOVERNING PROPERTIES IN A VORTEX TUBE

2021 ◽  
pp. 1-28
Author(s):  
Matthew Fuqua ◽  
James L. Rutledge
Keyword(s):  
Heat Capacity ◽  
Vortex Tube ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Volumetric Heat Capacity ◽  
Incoming Stream ◽  
Temperature Separation ◽  
External Sources ◽  
Total Temperature ◽  
Vortex Tubes

Abstract Although awareness of the phenomenon of temperature separation in Ranque-Hilsch vortex tubes dates back at least nine decades, some mystery surrounding the phenomenon remains to this day. These devices split an incoming stream of fluid into two streams—one with a greater total temperature than the incoming fluid and the other with a lower total temperature. This temperature separation is accomplished with no moving parts and no external sources of energy including heat transfer to or from the device. In attempts to understand the physics of the temperature separation, previous researchers have characterized the effect through various inlet temperatures and pressures as well as various gases with different properties. Unfortunately, the findings documented in the literature are sometimes inconsistent indicating the possibility that previously uncontrolled properties and flow conditions govern temperature separation to an unappreciated degree. In the present research, two new flow characteristics are examined for their role in temperature separation—volumetric heat capacity, ρC_p, and nozzle velocity. In the present experiments with air, it was found that by matching nozzle velocity and ρC_p—even with disparate pressures, temperatures, Reynolds numbers, and Mach numbers—the resulting temperature separation curves are identical. This is the first known documentation of such a finding. The results suggest that nozzle velocity is fundamental to scaling the performance of a vortex tube, while the nozzle volumetric heat capacity is also relevant to its behavior.

Investigations of Energy Separation Effect in Vortex Tube for Natural Gases

2013 ◽  
Vol 397-400 ◽  
pp. 205-208
Author(s):  
Wen Chuan Wang ◽  
Xiang Jun Fang ◽  
Shi Long Liu ◽  
Wen Long Sun
Keyword(s):  
Mass Fraction ◽  
Vortex Tube ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Energy Separation ◽  
Separation Effect ◽  
Natural Gases ◽  
Temperature Separation ◽  
Total Temperature ◽  
Cold Mass

This paper aims to investigate fixed composition natural gases including N2, CH4 and C2H4 energy separation effect in vortex tube. Energy separation phenomena of those gases were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of natural gases in fixed inlet boundary conditions were simulated. The results main factors were found that affect the energy separation with cold mass fraction being 0.7 and pressure drop ratio being 3.90. At the same time, this paper has illustrated the effects and tendencies of energy separation with gases in the tube under the same cold mass flow fraction and cold pressure ratio. The results show mixture gases total temperature difference effect is unchanged varied with the cold mass fraction; CH4% has no effect on the vortex cold end temperature separation, but varied of CH4% has an influence in total temperature and hot end separation effect; total temperature separation effect of CH4% was divided into two sections, one is0%-80%, and the other 80%-100%.

scholarly journals Computational Fluid Dynamic Prediction and Physical Mechanisms Consideration of Thermal Separation and Heat Transfer Processes Inside Divergent, Straight, and Convergent Ranque–Hilsch Vortex Tubes

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Adib Bazgir ◽  
Nader Nabhani ◽  
Bahamin Bazooyar ◽  
Ali Heydari
Keyword(s):  
Vortex Tube ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Numerical Data ◽  
Dynamic Prediction ◽  
Temperature Separation ◽  
Flow Phenomena ◽  
Stream Lines ◽  
Physical Phenomena ◽  
Vortex Tubes

AbstractThe design of Ranque–Hilsch vortex tube (RHVT) seems to be interesting for refrigeration and air conditioning purposes in industry. Improving thermal efficiency of the vortex tubes could increase the operability of these innovative facilities for a wider heat and cooling demand to this end; it is of an interest to understand the physical phenomena of thermal and flow patterns inside a vortex tube. In this work, the flow phenomena and the thermal energy transfer in RHVT are studied for three RHVT: straight, divergent, and convergent vortex tubes. A three-dimensional numerical analysis of swirling or vortex flow is performed, verified, and validated against previous experimental and numerical data reported in literature. The flow field and the temperature separation inside an RHVT for different configuration of straight, five angles of divergent hot tube (1 deg, 2 deg, 3 deg, 4 deg, and 6 deg) and five angle of convergent hot tube (0.5 deg, 0.8 deg, 1 deg, 1.5 deg, and 2 deg) are investigated. The thermal performance for all investigated RHVTs configuration is determined and quantitatively assessed via visualizing the stream lines for all three scenarios.

scholarly journals Effect of secondary swirl in supersonic gas and plasma flows in the self-vacuuming vortex tube

2018 ◽  
Vol 209 ◽  
pp. 00020 ◽  
Author(s):  
Vyacheslav Volov ◽  
Anton Lyaskin
Keyword(s):  
Pressure Drop ◽  
Shock Waves ◽  
Energy Loss ◽  
Flow Structure ◽  
Vortex Tube ◽  
Extreme Values ◽  
The Self ◽  
Temperature Separation ◽  
Loss Estimations ◽  
Vortex Tubes

This article presents the results of simulation for a special type of vortex tubes – self-vacuuming vortex tube (SVT), for which extreme values of temperature separation and pressure drop are realized. The main results of this study are the flow structure in the SVT and energy loss estimations on oblique shock waves, gas friction, instant expansion and organization of vortex bundles in SVT.

scholarly journals Similarities and differences between working processes of Ranque effect and Hartmann–Sprenger tube

2021 ◽  
Vol 5 (1) ◽  
pp. 61-70
Author(s):  
V. I. Kuznetsov ◽  
◽  
V. V. Makarov ◽  
A. Yu. Shander ◽  
◽  
...  
Keyword(s):  
Energy Exchange ◽  
Vortex Tube ◽  
Physical Models ◽  
Physical Processes ◽  
Dead End ◽  
Total Temperature ◽  
Similarities And Differences ◽  
Physical And Mathematical Models ◽  
Ranque Effect ◽  
Vortex Tubes

The physical and mathematical models of the processes occurring in the vortex tubes (Ranque effect) and Hartmann–Sprenger tube. The physical models most closely corresponding to the physical processes in these devices have been identified. The similarities and differences between the effects arising during the operation of vortex tubes and the Hartmann–Sprenger tube are found. The proof of the influence of viscosity on the Ranque effect and the interaction of gases in the Hartmann–Sprenger tube is given. Regularities of changes in total pressure and total temperature in a vortex tube and a Hartmann–Sprenger tube are given. The factors influencing the energy exchange in the vortex tube and the Hartmann–Sprenger tube are determined. The influence of the exchange of work and heat on the Ranque effect and the Hartmann–Sprenger tube is revealed. The mechanism of energy transfer between gas layers in a vortex tube and in a dead-end Hartmann– Sprenger cavity is found

Experimental Investigation of the Energy Separation in Vortex Tubes

1969 ◽  
Vol 11 (6) ◽  
pp. 567-582 ◽  
Author(s):  
H. H. Bruun
Keyword(s):  
Cross Sections ◽  
Energy Equation ◽  
Vortex Tube ◽  
Equations Of Motion ◽  
Energy Separation ◽  
Equal Importance ◽  
Order Of Magnitude ◽  
Axial Variation ◽  
Total Temperature ◽  
Vortex Tubes

Measurements of the state and the velocity distribution of air in a counterflow vortex tube have been undertaken. In order to determine the axial variation of the flow quantities, measurements were carried out in several cross-sections. The experimental results show that the velocity is predominantly tangential. A comparison of the order of magnitude of the radial and axial convection terms in the equations of motion and energy shows that these terms are of equal importance. The energy equation in terms of the total temperature is used as a basis for discussing the influence of turbulence in the flow on the separation of energy in the vortex tube.

Characteristics of an Underexpanded Jet and Its Surface Impingement for Combustion Burnthrough

2009 ◽  
Author(s):  
Zahid M. Hussain ◽  
Michael H. Coney ◽  
J. Barrie Moss ◽  
Peter T. Ireland ◽  
Stuart Jagger
Keyword(s):  
Reynolds Number ◽  
Vortex Flow ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Flow Visualisation ◽  
Free Jet ◽  
Plate Spacing ◽  
Temperature Separation ◽  
Wide Range ◽  
Total Temperature

The flow from an underexpanded free jet and a jet impinging on a perpendicular planar surface has been characterised for a pressure ratio (N) of 40 with a nozzle to plate spacing (L/D) of 3 nozzle diameters. Surface heatflux (Q), temperature (T), pressure (P) and flow visualisation techniques have been used extensively to examine the flow within the jet and on the plate surface. From these it is shown that the flow is non-axisymmetric in nature. The experimental programme has been conducted across several facilities within the UK which has allowed the influence of Reynolds number to be determined. The results of this work show marked similarities in flow characteristics irrespective of Reynolds number variation. Heat transfer on the impingement plate is largely determined by Taylor-Go¨rtler vortex flow and total temperature separation resulting from shearing flows. Evidence for Taylor-Go¨rtler vortex flow within the jet has been reinforced by comparison of the free jet element of this work with other research. Infra-Red camera measurements have confirmed the presence of strong total temperature separation on the impingement surface with local surface temperature step variation of greater than 200K (360°F) in the presence of a high temperature jet running at approximately 1900K (2960°F). This feature is dictated by this N and L/D and is shown to occur over a wide range of jet total temperature.

scholarly journals Numerical Simulations of Cryogenic Hydrogen Cooling in Vortex Tubes with Smooth Transitions

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1429
Author(s):  
Konstantin I. Matveev ◽  
Jacob Leachman
Keyword(s):  
Vortex Tube ◽  
Vortex Chamber ◽  
Smooth Transition ◽  
Working Fluid ◽  
Hydrogen Energy ◽  
Temperature Separation ◽  
Valuable Characteristic ◽  
Hydrogen Cooling ◽  
Smooth Transitions ◽  
Vortex Tubes

Improving efficiency of hydrogen cooling in cryogenic conditions is important for the wider applications of hydrogen energy systems. The approach investigated in this study is based on a Ranque-Hilsch vortex tube (RHVT) that generates temperature separation in a working fluid. The simplicity of RHVT is also a valuable characteristic for cryogenic systems. In the present work, novel shapes of RHVT are computationally investigated with the goal to raise efficiency of the cooling process. Specifically, a smooth transition is arranged between a vortex chamber, where compressed gas is injected, and the main tube with two exit ports at the tube ends. Flow simulations have been carried out using STAR-CCM+ software with the real-gas Redlich-Kwong model for hydrogen at temperatures near 70 K. It is determined that a vortex tube with a smooth transition of moderate size manifests about 7% improvement of the cooling efficiency when compared vortex tubes that use traditional vortex chambers with stepped transitions and a no-chamber setup with direct gas injection.

scholarly journals Testing a Gypsum Composite Based on Raw Gypsum with a Direct Admixture of Paraffin and Polymer to Improve Thermal Properties

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3241
Author(s):  
Krzysztof Powała ◽  
Andrzej Obraniak ◽  
Dariusz Heim
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Phase Change ◽  
Large Scale ◽  
Building Materials ◽  
Residential Buildings ◽  
Energy Performance ◽  
Polymer Content ◽  
Volumetric Heat Capacity

The implemented new legal regulations regarding thermal comfort, the energy performance of residential buildings, and proecological requirements require the design of new building materials, the use of which will improve the thermal efficiency of newly built and renovated buildings. Therefore, many companies producing building materials strive to improve the properties of their products by reducing the weight of the materials, increasing their mechanical properties, and improving their insulating properties. Currently, there are solutions in phase-change materials (PCM) production technology, such as microencapsulation, but its application on a large scale is extremely costly. This paper presents a solution to the abovementioned problem through the creation and testing of a composite, i.e., a new mixture of gypsum, paraffin, and polymer, which can be used in the production of plasterboard. The presented solution uses a material (PCM) which improves the thermal properties of the composite by taking advantage of the phase-change phenomenon. The study analyzes the influence of polymer content in the total mass of a composite in relation to its thermal conductivity, volumetric heat capacity, and diffusivity. Based on the results contained in this article, the best solution appears to be a mixture with 0.1% polymer content. It is definitely visible in the tests which use drying, hardening time, and paraffin absorption. It differs slightly from the best result in the thermal conductivity test, while it is comparable in terms of volumetric heat capacity and differs slightly from the best result in the thermal diffusivity test.

Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

2013 ◽  
Author(s):  
Jian Pu ◽  
Zhaoqing Ke ◽  
Jianhua Wang ◽  
Lei Wang ◽  
Hongde You
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Turbine Blade ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Flow Ratio ◽  
Lp Turbine ◽  
Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

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