Vortex Tube Research Articles

Numerical Investigation on Separation Efficiency of a Novel Hybrid Engine Air-Particle Separator

This paper proposes a novel design for a hybrid engine air-particle separator filter (HEAPS) that combines the vortex tube separator (VTS) with the inertial particle separator (IPS) to enhance separation efficiency. Helicopters often operate in harsh environments, such as deserts, and landing on unprepared runways poses a severe risk to turboshaft engines due to the ingestion of dust and sand. This can result in significant damage to the engine's rotating components, impacting its life, reliability, and performance. To protect the engine from erosion and damage, an engine air particle separator system (EAPS) is installed in the engine inlet. In this study, a comparative numerical simulation was conducted between the hybrid filter and the VTS using the commercial software ANSYS Fluent. The Reynolds-averaged Navier–Stokes equations (RANS) were used to simulate incompressible turbulent flow, and the trajectory of particles was tracked using the Discrete Phase Model (DPM). Particle trajectories and separation efficiency were analyzed for different particle sizes, inlet velocities, and bypass mass flow ratios between the scavenge channel and the core engine channel. The results show that the hybrid design provides excellent separation efficiency, with a recovery efficiency of over 97%.

Mean Flow Characteristics Downstream of a Vortex Tube Separator Array

Vortex tube separator (VTS) arrays are used to filter foreign particles from turboshaft engine intakes. Arrays may consist of hundreds of separators that share a common surrounding plenum, potentially allowing for significant interactions between the devices. However, most VTS studies have been limited to individual separators acting alone. The current study first involves an experimental investigation of the fluid flow emerging from the outlets of a VTS array installed in a wind tunnel. Particle image velocimetry is used to measure the flowfield at planes , , and downstream of the outlets, where is the inlet tube diameter of a separator. The results indicate that the emerging vortices quickly merge into a single vortex with high circumferential velocity concentrated near the edges of the duct, and that a central recirculation zone (CRZ) develops. This is in contrast to the flow from a single VTS, which does not have a clear CRZ. Comparisons to similar combustion swirler flows lead to the hypothesis that VTS arrays may uniquely generate fast-developing CRZs that produce strong axial flow gradients near or even within some VTS outlets. Such gradients will alter the filtration performance of affected VTSs, which is highly sensitive to flow rates. To explain the onset of recirculation that is exclusive to the array configuration, the framework of a momentum integral model has been developed and is presented here. Additionally, computer-aided design files of the experimental geometry along with inlet/outlet boundary conditions are being made available for any future computational validation studies of this complex flowfield.

Performance improvement of transcritical CO2 refrigeration cycle by integrating vortex tube expansion: Simulation and optimization

Since the critical temperature of CO2 is low and the working pressure is high, cycles using CO2 as a refrigerant are generally transcritical. Considering the large throttling loss and low system performance of the existing transcritical CO2 cycles, this paper proposes a general parameter matching method for transcritical CO2 cycles with vortex tube by using the self-defined functional blocks that can easily and quickly realize the parameter matching of components in refrigeration cycles with diverse architectures. Based on this new method, simulation and optimization of existing transcritical CO2 systems with or without vortex tube are implemented. A two-stage compression transcritical CO2 system with serial vortex tubes is proposed and proven to have a high cooling performance and less exergy loss in comparison with existing transcritical CO2 systems. Furthermore, the number of vortex tube(s) used and the coupling mode of vortex tube(s) with the transcritical CO2 system are also discussed. The results show that for the transcritical system with evaporators greater than two, the performance of the system with parallel vortex tubes is better than that of serial vortex tubes. When there are two evaporators and vortex tubes with a cold mass rate greater than 0.3, the performance of the system with serial vortex tubes is better than that of parallel vortex tubes. Finally, exergy analysis of the improved and existing transcritical CO2 cycles is conducted which shows that the exergy loss caused by the throttle valve is considerably reduced by using the vortex tube.

Large eddy simulation of tip-leakage cavitating flow around twisted hydrofoil with effects of tip clearance and skew angle

Tip-leakage cavitating flow around hydrofoils has attracted much research interest, but the complex structures of tip separation vortex (TSV) and tip-leakage vortex (TLV) have not been clearly resolved and discussed with the effects of tip clearance and skew angle yet. In the present work, large eddy simulation (LES) with multi-level octree grid refinement is used to investigate the tip-leakage flows around a series of twisted hydrofoils with various skew angle and tip clearance. High resolution is guaranteed by the normalized grid sizes of y+<1, Δx+∼50 and Δz+∼10, through which the predicted flow meets the criterion that at least 80% of the turbulent kinetic energy is resolved. The TSVs are identified to grow from the entire lower edge of the tip and twine with the TLV into a primary vortex tube, which leads to counter-rotating induced vortices (IV) strongly twisted around the primary vortex in the case of medium tip clearance but weakened for small one. Cavitation effect significantly accelerates the roll-up process of the vortices so that the primary vortex is formed earlier. The tip-leakage flow turns from wake-like to jet-like when the clearance is reduced, but the jet velocity diminishes markedly for extremely small clearance. The hydrofoil skewness barely makes a lift on the vortex tube, distinctive from the effect of tip clearance variation. The adverse pressure gradient induced by the skew angle has significant effect on the laminar–turbulent​ transition of the flow. The tip vortex flow induces strongly characterized laminar ant turbulent flow regions on the suction side, which continuously changes with the variation of the skewness.

Theoretical model and numerical simulation of high-gravity backwashing process for deep bed filter in oilfield

With the large-scale application of polymer flooding technology, the polymer concentration in produced water is increasing, which leads to incomplete regeneration of filter media by gravity field hydraulic backwashing technology only. In this study, the high-gravity backwashing technology is constructed by coupling gravity field and swirl field, which promotes the development of the oilfield. Based on the cascade theory, this paper establishes a mathematical expression of radial collision force in the high-gravity backwashing process in the vortex tube and solves a mathematical equation of high-gravity backwashing velocity gradient G based on the efficient zone of collision force action. Meanwhile, based on the discrete element method and computational fluid dynamics theory, the inter-particle collision regulation of the high-gravity backwashing process is simulated by the coupled FLUENT-EDEM method, and the high-efficiency zone of the backwashing process is verified. In this high-efficiency zone, the theoretical and simulated values of velocity gradient G for different high-gravity values match well, with differences ranging from –5.8 % to +7.1 %, indicating that the theoretical model of high-gravity backwashing is correct. When the high-gravity value is 210–240 g, the total impulse of the filter bed per unit time reaches a great value, and the backwashing velocity gradient G is 3047.1 s−1, which is much larger than the G value of combined air-water backwashing. The high-gravity backwashing technology breaks through the technical bottleneck of low efficiency in the action of the gravity field. It enriches and develops the gravity field hydraulic backwashing technology of the filter bed.

A novel battery thermal management model in hybrid vehicles using Ranque–Hilsch vortex tube

A novel battery thermal management model in hybrid vehicles using Ranque–Hilsch vortex tube

Experimental investigation on cooling performance of vortex tube with rectifier using Taguchi method

In this article, an experimental study was carried out to investigate the cooling efficiency of a vortex tube equipped with a rectifier utilizing the Taguchi method for analysis. The Coefficient of Performance (COP) was determined as the quality characteristics. In the current study, the inlet pressure, distance between the rectifier and the hot end, the position of the rectifier, the height of the rectifier, the number of blades, the length of blades, the inclination angle of blades with and without ring were selected as the key control factors and levels. Taguchi L18 orthogonal array was applied to design the experiments. The Signal-to-Noise Ratio (SNR), regression, Analysis of Variance (ANOVA) and residual analysis were applied to optimise the combination for COP of the vortex tube. The tests were also conducted to validate the reliability of the predicted optimisation method. Experimental results indicated that: (i) the predicted optimal value falls within a Confidence Interval (CI) of 95%. The analysis also revealed that the length of the blades could be the most influential control factor, accounting for 36.9% of the cooling performance. (ii) the height of the rectifier shows little impact, only contributing 4.7% to the overall cooling performance. (iii) the order of other control factors on COP was inlet pressure (21%), whether the rectifiers with or without ring (12.8%), distance between the rectifier and the hot end (7.9%), the inclination angle of blades (6.2%) and the number of blades (5.3%).

Study and Investigation of Microbial Influenced Corrosion Effect for Performance Analysis of Vortex Tube on Stainless Steel with and without Coating

Alloy material testing for stable the properties of Vortex tube and corrosion resistance, this research for specially for fabrication of Vortex tube and also in future may supplier will ask the properties and testing evidence we are going to provide week wise testing schedule. Microbial Influenced Corrosion (MIC) is a type of corrosion that happened on a metal's surface under the seawater. MIC occurs due to the colonization of microorganism on the surface, these microorganisms may be fungus, bacteria or algae. In this paper the E. Coli bacteria are used to investigate the MIC on metal sample of vortex chamber. A metal sample of vortex tube which is stainless steel is coated with different coating such as alocit, rubber, epoxy, and graphene. The samples for vortex tube with different coating are tested to find out the best one which can resist MIC better than the others. There are different tests carried out; wet and dry test, atmospheric test. To find the corrosion progress the weight loss and corrosion rate is found in the sample material to apply vortex tube. The hardness of the coating is done to find the best one. The optical microscope is used to understand the corrosion progress in the metal surfaces and for the hardness test. The result analyzed shows that graphene is the best coating because of its excellent properties in resisting and preventing MIC corrosion of vortex tube is a non-conventional cooling device, having no moving parts which will produce cold air and hot air from the source of compressed air without effecting the environment when a high-pressure air is tangentially injected into the vortex chamber, a strong vortex flow will be created which will be split into two air streams. Beyond that, the improvement in energy separation is minor, and Vortex Tube performance begins to deteriorate as shock waves form outside the nozzle. Without any moving parts or chemical reactions, a vortex tube (VT) can generate hot and cold streams from a single pressurised room temperature fluid.

Performance analysis and multi-objective optimization of a vortex tube integrated single-stage vapour compression refrigeration cycle

This paper evaluates the thermodynamic performance of a vortex tube integrated single-stage vapour compression refrigeration cycle (VTC) in a subcritical region. The thermodynamic evaluation consists of an energy and exergy analyses for VTC in order to determine the effect of various design and operating parameters on its performance. Moreover, the results of VTC are compared with those of a simple vapour compression refrigeration cycle (i.e., VCR) for the considered range of evaporator and condenser temperatures using R1234yf as a refrigerant. The analysis reveals that the cooling capacity of VTC is 14.53% – 49.73% higher than that of VCR for the considered range of condenser temperature. Also, the maximum COP of VTC is 5.59% – 27.32% higher than that of VCR. The exergetic efficiency of VTC is 5.62% – 27.33% higher than that of VCR. A multi-objective optimization using a genetic algorithm has been conducted, which suggests that the evaporator temperature is the major decisive parameter to find the suitability of various applications of the system based on VTC.

Effect of Aspect Ratio on Swept-Wing Dynamic Stall

The role of aspect ratio on the dynamic stall process of swept finite wings is investigated using high-fidelity implicit large-eddy simulations. Two aspect ratios ( and 8) are explored for a 30 deg swept wing (NACA 0012) pitching sinusoidally from an initial incidence of 4 deg to a maximum angle of attack of 22 deg with a reduced frequency of over one pitching cycle. The flow is simulated at a chord Reynolds number of and a freestream Mach number of . The unsteady three-dimensional flowfield for the higher-aspect-ratio wing showed similarity with the lower-aspect-ratio wing through the initial flow separation at the leading edge. Motion-induced effects promoted earlier initiation of the unsteady vortical structures at higher aspect ratios. The vortex tube at the larger span underwent significant distortion, which contrasted with the vortex observed at the lower span. The vortical structure eventually interacted with the trailing-edge vortex, which was not observed at . Examination of the unsteady loads detailed a larger lift slope, mean values, peak values, and earlier stall as the aspect ratio increased. Analysis of the aerodynamic pitch damping suggests the wing is less susceptible to local torsional instabilities than the wing.

An Experimental Study on the Energy Separation Performance of a Counter-Flow Ranque–Hilch Vortex Tube with Different Hot Tubes

An Experimental Study on the Energy Separation Performance of a Counter-Flow Ranque–Hilch Vortex Tube with Different Hot Tubes

Swirls in the solar corona

Context. Vortex flows have been found in the photosphere, chromosphere, and low corona in observations and simulations. It has been suggested that vortices play an important role in channeling energy and plasma into the corona. However, the impact of vortex flows on the corona has not been studied directly in a realistic setup. Aims. We investigate the role vortices play for coronal heating using high-resolution simulations of coronal loops. The vortices are not artificially driven and they arise, instead, self-consistently from magnetoconvection. Methods. We performed 3D resistive (magnetohydrodynamic) MHD simulations with the MURaM code. Studying an isolated coronal loop in a Cartesian geometry allows us to resolve the structure of the loop interior. We conducted a statistical analysis to determine vortex properties as a function of height from the chromosphere into the corona. Results. We find that the energy injected into the loop is generated by internal coherent motions within strong magnetic elements. A significant part of the resulting Poynting flux is channeled through the chromosphere in vortex tubes forming a magnetic connection between the photosphere and corona. Vortices can form contiguous structures that reach up to coronal heights, but in the corona itself, the vortex tubes get deformed and eventually lose their identity with increasing height. Vortices show increased upward directed Poynting flux and heating rate in both the chromosphere and corona, but their effect becomes less pronounced with increasing height. Conclusions. While vortices play an important role for the energy transport and structuring in the chromosphere and low corona, their importance higher up in the atmosphere is less clear since the swirls are less distinguishable from their environment. Vortex tubes reaching the corona reveal a complex relationship with the coronal emission.

Numerical Investigation on the Performance of Vortex Tube

Numerical Investigation on the Performance of Vortex Tube

Measuring the 3D wake of swimming snakes (Natrix tessellata) using volumetric particle image velocimetry.

We describe a method for measuring the 3D vortical structures produced by an anguilliform swimmer using volumetric velocimetry. The wake of freely swimming dice snakes (Natrix tessellata) was quantified, revealing the creation of multiple vortices along the body of the snake due to its undulation. The 3D structure of the vortices generally consisted of paired vortex tubes, some of which were linked together to form a hairpin structure. The observations match predictions from computational fluid dynamic studies of other anguilliform swimmers. Quantitative measurements allowed us to study vortex circulation and size, and global kinetic energy of the flow, which varied with swimming speed, vortex topology and individual characteristics. Our findings provide a baseline for comparing wake structures of snakes with different morphologies and ecologies and investigating the energetic efficiency of anguilliform swimming.

Machining of Hard-to-cut AISI 4462 Duplex Stainless Steel with an Environmentally Friendly Approach with Vortex Tube

Machining is a manufacturing process that can be used to produce precision machine parts and has many advantages. The first is the ability to achieve superior surface quality. Tool wear is an inevitable phenomenon that occurs during machining. It is affected by many machining conditions; therefore, this process needs to be monitored and controlled. In this study, tool wear and surface roughness tests were carried out on AISI 4462 duplex stainless-steel materials, known to be a hard-to-cut material. For this purpose, tool wear and surface roughness analyses were implemented by using the environmentally friendly vortex tube cooling system in addition to wet turning conditions for the first time. For both methods, experiments were conducted at a 1 mm depth of cut, 120 m/min cutting speed, and 0.1 mm/rev feed with a 90 mm cutting length for each pass. Both tool wear and surface roughness were examined at the end of each pass. The analysis showed that wet turning gave better results in terms of tool life (19.8 minutes of tool life) compared to 11.1 minutes of tool life in vortex turning. In contrast, the surface roughness values differed up to two times in some experiments, and the vortex tube experiments gave better surface roughness values in all passes. In addition, the vortex tube experiments showed less built-up-edge (BUE) formation than the wet-turning experiments.

Influence of flow straightener structure on energy separation performance of Ranque-Hilsch vortex tube based on energy and exergy analyses

The energy separation characteristics of vortex tube installed with flow straightener were experimentally investigated for better promotion of the application of vortex tube in the improvement of energy efficiency and sustainability. Systematic evaluation of the vortex tube with straightener was performed by applying a combined method of energy as well as exergy analysis, and the temperature separation process facilitated by the flow straightener was analyzed in depth. The effects of cold mass fraction (μc = 0.2–0.8), blades number (N = 0, 2, 4, 6 and 8), diameter ratio (ε = 0, 0.2, 0.4, 0.6 and 0.8), blade angle (θ = 0°, 30°, 60° and 90°) and installation position (Ls/L = 0.25, 0.45, 0.65 and 0.85) on cold and hot temperature differences, coefficient of performance, exergy efficiency and internal temperature field were investigated experimentally. The results show that as the blades number, blade angle and installation position increase, the cold and hot temperature difference and coefficient of performance first ascend and then descend. The presence of a hole in the center of flow straightener weakens the energy separation performance of vortex tube. A flow straightener with 4 blades, 0 diameter ratio, 60° blade angle and 0.65 installation position produces optimum energy separation performance and exergy efficiency.

Experimental Investigation and Analyze the Effect of Varying L/D on Thermal Performance of Vortex Tube

Traditional vapour compression systems are known to be costly and require regular maintenance due to their numerous moving parts. However, a promising alternative is the vortex tube refrigeration system, which operates without any moving components. This system functions as a miniature refrigerator by effectively dividing the compressed gas into two separate streams: one hot and one cold. In order to maximize the temperature reduction achieved by this system, a study was conducted to assess its thermal performance based on various geometric parameters. Specifically, the investigation focused on the influence of the length-to-diameter (L/D) ratio of the vortex chamber under different inlet pressure conditions. Experimental trials were conducted with different L/D ratios, and the analysis primarily focused on the extent of low temperature fraction attained. The results highlighted the significance of the L/D ratio in determining the overall performance of the vortex tube cooling system

Reducing Energy Consumption and CO2 Emissions in Natural Gas Preheating Stations Using Vortex Tubes

This work proposes an innovative method for adjusting the natural gas from the grid to the consumer pipeline requirements in a full-scale pressure reduction station. The use of two counterflow vortex tubes instead of the traditional boiler to preheat the gas before throttling is demonstrated as a powerful alternative. Thus, a reduction of fossil fuel consumption is reached, which amounts to 7.1% less CO2 emitted. To ensure the optimal configuration, the vortex tube was thoroughly characterized in laboratory facilities using nitrogen as the working fluid. Various operating conditions were tested to determine the most efficient setup. Computational Fluid Dynamics (CFD) simulations were conducted with nitrogen to validate the behavior of the vortex tube. Subsequently, the working fluid was switched to methane to assess the performance differences between the two gases. Finally, the vortex tubes were deployed at a full-scale installation and tested under real consumption demand. The results obtained from this study offer promising insights into the practical implementation of the proposed method for adjusting the natural gas flow, highlighting its potential for reducing fossil fuel consumption and minimizing CO2 emissions. Further improvements and refinements can be made based on these findings.

Hydrodynamic Model of Hydraulic Engineering Based on Trigonometric Function Relation Equation

Abstract In order to explore the application of fluid mechanics technology in water conservancy and hydropower stations, the author proposes the study of hydraulic engineering fluid mechanics model based on trigonometric function relationship equation. According to standard k- ε Double equation and Reynolds time average (N-S) equation, given the runner boundary conditions, establish the mathematical model of the internal flow of the hydraulic turbine. Through CFD simulation technology, the runner of hydraulic turbine is numerically simulated to obtain the velocity distribution and blade pressure distribution inside the runner, movable guide vane and fixed guide vane, the reliability of the design is improved, and the application of CFD technology in hydropower project is analyzed with an example. The results show that, when the diameter of guide vane distribution circle is 4760mm, the scheme is optimal, and the relative efficiency under the optimal working condition is 96.35%. The flow of the modified runner from the inlet of the volute to the outlet of the draft tube is very stable under the optimal working condition, and there is no obvious vortex, especially there is no obvious vortex belt and vortex at the outlet of the runner; There is no obvious vortex in the draft tube, the flow on both sides of the pier is very uniform, and the flow on one side is not significantly greater than that on the other side, which fully shows that the flow performance of the modified runner is good. After reconstruction, the runner outlet flow field is good, and the internal flow line of the draft tube is smooth. The application prospect of hydrodynamic algorithm for hydraulic engineering is relatively broad.

Numerical analysis study on the application of three-lobed vortex tube in low-production wells

Numerical analysis study on the application of three-lobed vortex tube in low-production wells