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.

Vortex Tube Applications in Micro-Power Generation

2002 ◽  
Author(s):  
Selin Arslan ◽  
Bojan Mitrovic ◽  
Michael R. Muller
Keyword(s):  
Pressure Drop ◽  
Power Systems ◽  
Steam Turbine ◽  
Vortex Tube ◽  
Low Pressure ◽  
Total Efficiency ◽  
Pressure Drops ◽  
Large Pressure ◽  
Micro Power ◽  
Vortex Tubes

The purpose of this paper is to study vortex tube performance characteristics and the use of vortex tubes to increase the total efficiency of power systems, especially micropower systems. A vortex tube is a device in which compressed air is made to swirl and separate into two low-pressure streams, one with higher temperature than the entry and the other lower. The lack of moving parts and electricity make the vortex tube attractive for a number of specialized applications where simplicity, robustness and reliability are desired. Vortex tubes are currently used for industrial cooling applications, separation technologies, and chemical analysis. It is well known that the temperature difference between the hot and cold sides of the vortex tube scales with the pressure drop. Also, at any pressure drop, the temperatures and flow rates are dependent on the flow fractions between the hot and cold sides. Data is available for large pressure drops, but this paper presents experimental results at low-pressure drops optimizing the operational modes for various applications. The micro-power systems under consideration include micro-turbines, which evolved out of automotive turbocharger technology. The use of vortex tubes in power systems has received some attention but the use of both the hot and cold streams has never been considered. In this work, we consider such dual use. As an example of an application, the vortex tube is considered in conjunction with a heat recovery steam generator (HRSG). The vortex tube splits the turbine exhaust flow into hotter and cooler streams. The cooler stream is still hot enough to supply all needed heat in the economizer section, leaving the hotter stream to increase the exit temperature from the superheater. In this way both the air leaving the HRSG and going to the steam turbine will have an increased enthalpy and cycle efficiencies are improved. In addition, steam turbine exit quality is increased.

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.

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.

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 Physical modelling of energy losses at surcharged three-way junction manholes in drainage system

2021 ◽  
Author(s):  
Q. Li ◽  
J. Xia ◽  
M. Zhou ◽  
S. Deng ◽  
H. Zhang ◽  
...  
Keyword(s):  
Energy Loss ◽  
Flow Structure ◽  
Water Depth ◽  
Drainage System ◽  
Physical Modelling ◽  
Head Loss ◽  
Geometrical Parameters ◽  
Flow Discharge ◽  
Discharge Ratio ◽  
Loss Coefficients

Abstract Motivated by the observation that vortex flow structure was evident in the energy loss at the surcharged junction manhole due to changes of hydraulic and geometrical parameters, a physical model was used to calculate energy loss coefficients and investigate the relationship between flow structure and energy loss at the surcharged three-way junction manhole. The effects of the flow discharge ratio, the connected angle between two inflow pipes, the manhole geometry, and the downstream water depth on the energy loss were analyzed based on the quantified energy loss coefficients and the identified flow structure. Moreover, two empirical formulae for head loss coefficients were validated by the experimental data. Results indicate that the effect of flow discharge ratio and connected angle are significant, while the effect of downstream water depth is not obvious. With the increase of the lateral inflow discharge, the flow velocity distribution and vortex structure are both enhanced. It is also found that a circular manhole can reduce local energy loss when compared to a square manhole. In addition, the tested empirical formulae can reproduce the trend of total head loss coefficient.

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