Counter Flow Ranque Hilsch Vortex Tube Research Articles

Estimation of Ranque-Hilsch vortex tube performance by machine learning techniques

This study planned to model a counter-flow Ranque-Hilsch Vortex Tube (RHVT) using compressed air and oxygen gas by machine learning to separate the thermal temperature. From within machine learning models, Linear Regression (LR), Support Vector Machines (SVM), Gaussian Process Regression (GPR), Regression Trees (RT), and Ensemble of Trees (ET) were preferred. By leaving the outlet control valve on the hot fluid side fully open, data were received for each material and nozzle at RHVT with inlet pressure starting from 150 kPa and up to 700 kPa at 50 kPa intervals. In the counter flow RHVT, the lack in the literature has been tried to be eliminated by modeling the RHVT by finding the difference (ΔT) between the temperature of the cold flow exiting (Tc) and the temperature of the leaving hot flow (Th). When analyzing each of the machine learning models in the study, 80% of all data was used as training data, 20% of all data was used for the test, 70% of all data was used as training data, and 30% of all data was used for the test. As a result of the analysis, when both air and oxygen fluids were used, the GPR method gave the best result with 0.99 among the machine learning models in two different test intervals of 70%–30% and 80%–20%. The success of other machine learning models differed according to the fluid and model used.

THERMAL TEMPERATURE ESTIMATION BY MACHINE LEARNING METHODS OF COUNTERFLOW RANQUE-HILSCH VORTEX TUBE USING DIFFERENT FLUIDS

In the counterflow Ranque-Hilsch vortex tube (RHVT), the output control valve on the hot fluid side is left entirely open. The data were obtained using polyamide and brass materials and nozzles at 50 kPa intervals from 150 kPa to 700 kPa inlet pressure. In counterflow RHVT, the difference (ΔT) between the temperature of the cold outflow and the temperature of the outgoing hot flow was found, and the RHVT was modeled. The deficiency in the literature was tried to be eliminated. In this study, we planned the modeling of a counterflow RHVT using compressed air, oxygen, and nitrogen gas with machine learning models to predict the thermal temperature. Linear regression (LR), support vector machines (SVM), Gaussian process regression (GPR), regression trees (RT), and ensemble of trees (ET) machine learning methods were preferred in this study. While each of the machine learning methods in the study was analyzed, 75% of all data was used as training data, 25% as a test, 65% as training data, and 35% as testing data. As a result of the analysis, when the temperatures of air, oxygen, and nitrogen gases (ΔT) were compared, the Gaussian process regression method, which is one of the machine learning models, gave the best result with 0.99 in two different test intervals, 75-25%, and 65-35%. In the ΔT estimations made in all fluids, much better results were obtained in the machine learning models estimations of nitrogen gas when compared to other gases.

Optimization of Ranque–Hilsch vortex tube performances via Taguchi method

In this study, by considering the changes in inlet pressures, connection nozzle materials and the number of orifices, the performances of Ranque–Hilsch vortex tubes (RHVTs) were modelled by multiple linear regression method at which carbon dioxide (CO2) was used as compressed fluid, and optimum operating conditions were tried to be determined by Taguchi method. In the experiment, counterflow RHVTs having O10 mm inner diameter and 100 mm body length were used, hot fluid outlet of which was left completely open. In the tests designed using Taguchi L16 mix type (8 × 1 2 × 3) orthogonal array, 8 different inlet pressures (200, 250, 300, 350, 400, 450, 500 and 550 kPa), 2 different types of connections (parallel and series), 2 different types of nozzle materials (brass and polyamide) and 2 different numbers of orifices (4 and 6) were chosen as control factors and levels. Maximum temperature gradient (∆T) was determined as quality characteristics, and RHVT’s performance tests were done. In order to determine the effect rates of selected control factors on quality characteristics (∆T), analysis of variance (ANOVA) was applied within 95% confidence level. According to the statistical results, it was determined that ΔT values were mostly influenced by the inlet pressure and this was followed by connection type, number of orifices and nozzle material. With the confirmation test performed, reliability of the optimization was tested and confirmed.

Evaluation and Optimization of O2 Used Ranque-Hilsch Vortex Tube Performance

ABSTRACT Ranque-Hilsch Vortex Tube (RHVT) is a mechanic system which can make heating and cooling by using basic heat transfer laws with a compressed fluid. Environmental friendly RHVT is widely used in cooling systems in medicine, electronics, and computer sectors, particularly in the food sector. In this study, the performances of parallel RHVTs in which oxygen (O2) gas is used were reviewed considering different inlet pressures, nozzle materials and orifice numbers. Test results were modeled by multiple linear regression method and regression equation was derived. Besides, Signal/Noise (S/N) ratios of the designed test results were calculated using Taguchi L16 mix type (4 × 2 2 × 1) orthogonal sequence, and optimum conditions were determined. Throughout the test, hot fluid outlet valve of the counter flow RHVTs having Ø10 mm inner diameter and 100 mm body length was completely left open. As control factors and levels, four different inlet pressures (200, 350, 500, and 650 kPa), four different number of orifices (three, four, five, and six), and two different nozzle materials (brass and polyamide) were selected. For quality characteristics, maximum temperature gradient (∆T) was determined. In order to determine the effect rates of the control factors on quality characteristics (∆T), variance analysis (ANOVA) was applied to test results at 95% confidence level. According to statistical results, it was determined that the response rates of ΔT values from the control factors were determined as inlet pressure, the number of orifices and nozzle material, respectively. Validity of the optimization was checked with confirmation tests, and the optimization proved to be used in evaluation of RHVT performances.

Performance Assessment of Parallel Connected Ranque–Hilsch Vortex Tubes Using Nitrogen, Oxygen, and Air With Brass and Polyamide Nozzles: An Experimental Analysis

Abstract In this study, heating and cooling performances of two vortex tubes connected in parallel using different working fluids were compared. In experimental studies, oxygen, nitrogen, and air were used as working fluids in counterflow Ranque–Hilsch vortex tube (RHVT) and performance evaluation was performed. Nozzles made of polyamide and brass are used, and the number of these nozzles is 2, 4, and 6. Compressed working fluids were used to operate the vortex tube system at different inlet pressure values varying from 150 kPa to 600 kPa with 50 kPa increment. The geometric characteristics of the vortex tube are the length of the hot tube and the diameter of the orifice, which are 100 mm and 7 mm, respectively. Experiments were performed with the hot flow outlet valve fully open. The thermodynamic performance of the parallel connected vortex tube system was determined by performing exergy analysis. As a result of experimental studies, the highest performance of parallel connected RHVT system was obtained when nitrogen was used as a working fluid with brass-six-nozzle at 600 kPa.

Investigation of the thermal separation in a counter-flow Ranque-Hilsch vortex tube with regard to different fin geometries located inside the cold-tube length

A Ranque-Hilsch vortex tube is a mechanical device in absence of any portable part or work input and significantly separates the inlet gas stream into hot and cold gas which provides a variety of applications. Current research consists a three-dimensional numerical model at steady state condition using installed fins on cold tube. Six different geometry were chosen for fins including triangle, square, rectangle, circle, parallelogram and trapezium. The outcome data of the research then is verified with compare to prior experiment results brought in literature. This article surveys the influence of different fin shapes on critical performance parameters of cold temperature difference, hot temperature difference, isentropic efficiency and COP numerically. The modeling results indicate that the parallelogram and rectangular fins have the highest and lowest cold temperature difference, isentropic efficiency and COP, respectively. It was also observed that the greatest COP and efficiency happens at pressure loss ratio equal to 0.65 at which, the optimum performance parameters of parallelogram fin for cold temperature difference, hot temperature difference, isentropic efficiency and COP were 35, 35.3, 0.279 and 33 respectively; whereas, these parameters were 30, 30, 0.255 and 23.9 for rectangular fin, respectively.

Numerical CFD analysis and experimental investigation of the geometric performance parameter influences on the counter-flow Ranque-Hilsch vortex tube (C-RHVT) by using optimized turbulence model

This research article demonstrates how using different turbulence models may affect the temperature detachment (the temperature diminution of cold air (∆Tc = Ti − Tc)) inside straight counter-flow Ranque-Hilsch Vortex Tube (RHVT). The code is utilized to find the optimized turbulence model for energy separation by comparison with the experimental data of the setup. To obtain the results with a minimum error, various turbulence models have been investigated in steady state and transient time-dependence modes. Results show that RNG k-e turbulence model has the best correspondence with the obtained experimental data from the setup; therefore, by using a RNG k-e turbulence model with respect to Finite Volume Method (FVM), all the computations have been carried out. Moreover, some geometric parameters are focused on the length of hot tube and number of nozzle intakes within divergent and convergent hot-tube. Numerical results present that there is an optimum angle for obtaining the highest refrigeration performance, and 2ο divergence is the optimal candidate under our numerical analysis conditions. Length of hot tube which exceeds a critical length has slight effect on the refrigeration capacity. The critical length is L = 166 mm in our study. Temperature reduction sensitivity can be reduced by increasing number of nozzles and maximum temperature reduction can be obtained.

Experimental Study About Performance Analysis of Parallel Connected Ranque–Hilsch Counter Flow Vortex Tubes With Different Nozzle Numbers and Materials

An experimental analysis for parallel connected two identical counter flow Ranque–Hilsch vortex tubes (RHVT) with different nozzle materials and numbers was conducted by using compressed air as a working fluid in this paper. Heating and cooling performance of vortex tube system (circuit) and the results of exergy analysis are researched comprehensively according to different inlet pressure, nozzle numbers, and materials. Nozzles made of polyamide plastic, aluminum, and brass were mounted into the vortex tubes individually for each case of experimental investigation with the numbers of nozzles 2, 3, 4, 5, and 6. The range of operated inlet pressure 150–550 kPa with 50 kPa variation. The ratio of length–diameter (L/D) of each vortex tube in the circuit is 14 and the cold mass fraction is 0.36. Coefficient of performance (COP) values, heating, and cooling capacity of the parallel connected RHVT system were evaluated. Further, an exergy analysis was carried out to evaluate the energy losses and second law efficiency of the vortex tube circuit. The greatest thermal performance was obtained with aluminum-six-nozzle when taking into account all parameters such as temperature difference, COP values, heating and cooling capacity, and exergy analysis.

Computational fluid dynamics comparison of separation performance analysis of uniform and non-uniform counter-flow Ranque-Hilsch Vortex Tubes (RHVTs)

Computational fluid dynamics comparison of separation performance analysis of uniform and non-uniform counter-flow Ranque-Hilsch Vortex Tubes (RHVTs)

Experimental investigation of thermal performance of parallel connected vortex tubes with various nozzle materials

This paper is about experimental investigation for thermal performance of two identical parallel connected counter flow Ranque-Hilsch vortex tubes by using different orifice nozzle numbers and nozzle materials and also compressed air as a working fluid. The effects of nozzle numbers and materials on thermal performance by applying compressed air at the inlet at different pressures were experimentally determined. Experimental analyses were carried out by using polyamide plastic, aluminum and brass as nozzle materials with inlet pressure range 150–550 kPa with 50 kPa increment. Orifices having 2, 4 and 6 nozzle numbers were used in the vortex tubes. The length – diameter ratios (L/D) of the vortex tubes are 14 and the cold mass fractions are 0.36. The results of experimental studies revealed that the maximum performance was obtained with aluminum nozzles with nozzle number 6 at 550 kPa inlet pressure.

Seri ve Paralel Bağlı Karşıt Akışlı Ranque-Hilsch Vorteks Tüpün Isıtma–Soğutma Performansının Karşılaştırılması

In this study, two counter flow Ranque-Hilsch Vortex Tubes with body length 100 mm and inlet diameter 7 mm were used having no moving parts except a control valve for adjustment of volume flow rates. Two counter flow type Ranque-Hilsch Vortex Tubes were connected with each other with serial and parallel. Compressed air was used as a working fluid with pressure values from 200 kPa to 600 kPa with 50 kPa variation. Polyamide plastic, aluminum and brass were used as nozzle materials with nozzle number of six. Heating and cooling of a serial and parallel connected Ranque-Hilsch Vortex Tube were experimentally investigated and the results were evaluated with graphical representations.

Experimental Investigation of Cooling - Heating Performance of Counter Flow Ranque-Hilsch Vortex Tubes Having Different Length Diameter Ratio

Bu calismada, 6 nozullu karsit akisli Ranque-Hilsch Vorteks Tupu deneysel olarak incelenmistir. Uzunlugunun capa orani (L/D) 10 ve 12.5 olan karsit akisli Ranque-Hilsch Vorteks Tupunde 200 kPa’ dan 600 kPa basinc degerine kadar 50 kPa araliklarla basincli akiskan olarak hava kullanilmistir. L/D 10 ve 12.5 oranlarinda olusan enerji ayrisma olayi deneysel olarak incelenmistir. Deneysel sonuclari grafiklerle degerlendirilerek performanslarinin arttirilmasina yonelik onerilerde bulunulmustur.

An experimental and exergy analysis of a thermal performance of a counter flow Ranque–Hilsch vortex tube with different nozzle materials

In this study an experimental analysis was carried out about a counter flow Ranque–Hilsch vortex tube with different nozzle materials. In order to observe the influences of working fluids on vortex tube, thermal performance oxygen and air were used as working fluids for different inlet pressure. Fiberglass, aluminum and steel were used as nozzle materials. The main object of this study is to investigate thermal effect of nozzle materials and working fluids on thermal performance of the vortex tube. Experimental studies were made by using three different nozzle materials (fiberglass, aluminum and steel) with inlet pressure between 150 kPa to 700 kPa with arrange of 50 kPa increment. The fraction of cold mass was kept at 0.36 and the ratio of vortex tube (L/D) was taken 10. Also an exergy analysis was carried out for each case. This study revealed that steel as a nozzle material has the highest value of temperature gradient for air as a working fluid.

Exergy analysis of a counter flow Ranque–Hilsch vortex tube for different cold orifice diameters, L/D ratios and exit valve angles

An experimental investigation is made to find out the effects of the cold end orifice diameters, length to diameter ratio and exit valve angles on the heating and cooling performance of the counter flow Ranque–Hilsch vortex tube with air as a working fluid. The tube and cold end orifices used at these experiments are made of brass. Three cold end orifices (5, 6 and 7 mm) have been manufactured and are used five different L/D ratios (15 plain tube, 15–18 with 4° divergence angle) and exit valve angles (30°–90°). Inlet pressures were adjusted from 200 to 600 kPa with 100 kPa increments, and the exergy loss, exergy efficiency was determined. As a result of the experimental study, it is determined that the exergy loss between the hot and cold fluid is decreased with increasing of the cold end orifice diameter. Exergy efficiency decreases with increase in L/D ratio. It is also concluded that diverging vortex tube produces lower exergy loss as compared to plain tube. Valve angles have significant effect on hot end exergy loss of the vortex tube.

ЧИСЕЛЬНЕ МОДЕЛЮВАННЯ РОЗПОДІЛУ ТЕМПЕРАТУРИ В ПОТОЦІ МЕТАНУ В ВИХРОВИЙ ТРУБІ РАНКА-ХІЛША

In present numerical research, the temperature separation in methane stream within a counter flow Ranque-Hilsch vortex tube was investigated. A complete three-dimensional geometry of the vortex tube was used to generate a high-density computational grid. A vortex tube with two tangential inlet nozzles, an axial cold stream outlet and a circumferential hot stream outlet was considered. Methane was used as a fluid along with Peng-Robinson cubic equation of state. Fluid properties like total temperature and total pressure were analyzed for a range of inlet mass flow rates and inlet total pressure values. Also the total pressure and total temperature distribution along the axial direction was investigated. The temperature separation effect is more significant for air then for methane at all investigated pressures. Created model can be used to design industrial vortex tubes for oil and gas industry where methane is a main product.

Experimental Investigation of Temperature Separation in a Counter-Flow Vortex Tube

An experimental study of a counter-flow Ranque–Hilsch vortex tube is reported here. Literature has been divided over the mechanism of energy transfer responsible for the temperature separation in the vortex tube. A black box approach is used to design experiments to infer the relative roles of heat transfer and shear work transfer in the counter-flow vortex tube. To this end, the stagnation temperature and the mass flow rates are measured at the inlet and the two outlets. In addition, pressure measurements at the stagnation condition and at the inlet section to the vortex tube were made. Based on these experiments, it is reasoned that the predominant mode of energy transfer responsible for temperature separation in a counter-flow vortex is the shear work transfer between the core and the periphery.

CFD Study on the Effects of Nozzle Number on Turbulent Flow and Energy Separation in a Ranque-Hilsch Vortex Tube

In this paper, the effects of nozzles number on the internal flow in a counter flow Ranque-Hilsch vortex tube (RHVT) are studied. A 3D structured discretized model of a counter flow multi nozzle RHVT is developed to study the dynamic behaviour of the highly swirling, compressible turbulent flow. Simulations of the turbulent flow are performed using standard k-ε model with 2, 4, 6 and 8 number of nozzles at the computational inlet. Total temperature profiles and total energy separations are studied as a function of nozzle number and total nozzle cross section area. It is observed that cooling effect increases as the nozzle number increases irrespective of total nozzle cross section area.

Rule-Based Mamdani-Type Fuzzy Modeling of Heating and Cooling Performances of Counter Flow Ranque-Hilsch Vortex Tubes with Different Geometric Construction for Brass

In this study, thermal performances of counter flow Ranque-Hilsch vortex tubes were experimentally investigated and modeled with a Rule Based Mamdani-Type Fuzzy (RBMTF) modeling technique. The vortex tubes were made of brass. Diameter of vortex tube (D) was 10 mm. Length of vortex tube (L) was 10D, 11D, 12D, 13D, 14D. Input parameters (ξ, L/D) and output parameters (ΔTh, ΔTc) were described by RBMTF if-then rules. 45 experimental data sets were used in the training step. R2 for the ΔTh was found to be 99.42 % and R2 for the ΔTc was 99.66 %. The actual values and RBMTF results demonstrated that RBMTF can be successfully used for the determination of heating and cooling performances of counter flow RHVT with different geometric constructions for brass.

Investigation of Performance of Heating and Cooling of Counter Flow Ranque-Hilsch Tubes with L/D=15, 16, 17, 18 for Brass

In this study, heating and cooling performances of counter flow Ranque-Hilsch vortex tubes (RHVTs) were experimentally investigated for brass. The vortex tubes were made of brass. Diameter of vortex tube (D) was 10 mm. Length of vortex tube (L) was 15D, 16D, 17D and18D. The number of nozzles (Nn) was 5. The conical edges of the plugs have a slope of 30o angle. Working pressure of Ranque-Hilsch was 460 kPa (absolute). According to the experimental results, the maximum heating performance of the RHVT system was found to be 39,5 °C at P17 and the maximum cooling performance of the RHVT in this study was found to be-28,6 °C at P18. An increase in fraction of cold flow (ξ) led to a increase in the heating performance.

Rule-based Mamdani-type fuzzy modeling of heating and cooling performances of counter-flow Ranque–Hilsch vortex tubes with different geometric construction for steel

In this study, heating and cooling performances of counter-flow Ranque–Hilsch vortex tubes (RHVT) were experimentally investigated and modeled with a RBMTF (Rule-Based Mamdani-Type Fuzzy) modeling technique. Input parameters (ξ, L/D) and output parameters ΔTh, ΔTc were described by RBMTF if-then rules. 81 experimental data sets were used in the training step. Numerical parameters of input and output variables were fuzzificated as linguistic variables: Very Very Low (L1), Very Low (L2), Low (L3), Negative Medium (L4), Medium (L5), Positive Medium (L6), High (L7), Very High (L8) and Very Very High (L9) linguistic classes. R2 for the ΔTh was found to be 99.60% and R2 for the ΔTc was 99.80%. The actual values and RBMTF results indicated that RBMTF can be successfully used for the determination of heating and cooling performances of counter-flow RHVT with different geometric constructions for steel.