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Maziar Arjomandi - One of the best experts on this subject based on the ideXlab platform.
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Experimental study of the flow structure in a Vortex Tube
2020Co-Authors: Maziar Arjomandi, R KelsoAbstract:With the single injection, a Vortex Tube generates cold and hot stream from two exits respectively, which was first found and investigated by Ranque. Different explanations for the temperature separation in a Vortex Tube have been proposed since the invention of the device. However, due to the difference and conflicts among those explanations, a clarification of the thermal separation is still required. Understanding of the flow behaviour inside a Vortex Tube is an essential requirement in exploring the thermal separation. This paper reports on an experimental study in progress exploring the flow structure in a Vortex Tube. Flow properties in a Vortex Tube are measured and used to clarify the flow structure inside the Tube. The velocity distributions along the Tube are presented, which are different from previous studies. The transition from a forced Vortex at the cold end to a free Vortex near the hot end was first observed, which agrees with the author's previous study. The flow structures found in this research show positive supports for the proposed hypothesis of the temperature separation in the Vortex Tube.
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energy analysis within a Vortex Tube
Experimental Thermal and Fluid Science, 2014Co-Authors: Maziar Arjomandi, R KelsoAbstract:The generation of separated cold and hot streams from a single injection in a Vortex Tube is known as the Ranque effect. Since its invention, several explanations concerning the phenomenon of thermal separation in a Vortex Tube have been proposed, however there has not been a consensus, due to the complexity of the physical process inside the Tube. This paper proposes an explanation for the temperature separation in a Vortex Tube based on an experimental study focusing on the flow structure and energy analysis inside the Tube. Using the measured flow properties inside the Tube, the exergy density distribution along the Vortex Tube was calculated, from which the reasons for the temperature separation were identified. The good agreement of the exergy density analysis with findings from other experimental work supports the validity of the proposed hypothesis.
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the working principle of a Vortex Tube
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Maziar Arjomandi, R KelsoAbstract:The generation of cold and hot streams from a single injection in a Vortex Tube has been investigated by many researchers, aiming to define the primary reasons for the separation. This paper reports a detailed description of the flow behaviour inside a Vortex Tube and addresses the mechanism for the generation of cold and hot streams in a Vortex Tube, which is confirmed by different experimental methodologies, including visualization of the flow structure in a water-operated Vortex Tube, and measurement of velocity profiles in both water- and air-operated Vortex Tubes. Estimation of the theoretical temperature drop based on the pressure gradient of a forced Vortex flow is addressed in this paper, and good agreement with the experimental results was observed. Exergy analysis of the flow properties in an air-operated Vortex Tube indicates that there is no outward energy transfer in the hot region of the Vortex Tube. Furthermore, the governing factor for the temperature rise is attributed to the stagnation and mixture of the flow structure. Based on the proposed mechanism, the predicted performance of the Vortex Tube with variable geometrical parameters, were congruent with the experimental results, underpinning the validity of the proposed mechanism.
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experimental study of the thermal separation in a Vortex Tube
Experimental Thermal and Fluid Science, 2013Co-Authors: Maziar Arjomandi, R KelsoAbstract:A Vortex Tube, a simple mechanical device capable of generating separated cold and hot fluid streams from a single injection, has been used in many applications, such as heating, cooling, and mixture separation. To explain its working principle, both experimental and numerical investigations have been undertaken and several explanations for the temperature separation in have been proposed. However, due to the complexity of the physical process in the Vortex Tube, these explanations do not agree with each other well and there has not been a consensus. This paper presents an experimental study of the flow properties in a Vortex Tube focusing on the thermal separation and energy transfer inside the Tube. A better understanding of the flow structure inside the Tube was achieved, based on the observed three-dimensional velocity, turbulence intensity, temperature and pressure distributions. The gradual transformation of a forced Vortex near the inlet to a free Vortex at the hot end is reported in this work. The calculated exergy distribution inside the Vortex Tube indicates that kinetic energy transformation outwards from the central flow contributes to the temperature separation. Experimental results found in this research show a direct relationship between the formation of hot and cold streams and the Vortex transformation along the Tube.
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experimental study of the flow structure in a counter flow ranque hilsch Vortex Tube
International Journal of Heat and Mass Transfer, 2012Co-Authors: Maziar Arjomandi, R KelsoAbstract:Abstract The mechanism of the temperature separation in a Ranque–Hilsch Vortex Tube has been investigated since the discovery of this phenomenon. In spite of being investigated by many researchers, no consensus has yet been reached regarding the mechanism’s hypothesis. This paper reports on a study in progress exploring the temperature separation in a counter-flow Vortex Tube. The effects of the geometrical parameters, including inlet nozzles, cold exit, hot exit and length of the Tube, were investigated, which indicated the settings for the best performance of the Vortex Tube. Flow properties in the Vortex Tube were measured and used to understand the flow structure inside the Tube. Accurate measurements of the three-dimensional velocity distribution in the Tube were conducted. The results provided enough evidence that the flow in the Tube consists of a forced Vortex formed near the inlet gradually transforming to a free Vortex at the hot end. Experimental results found in this research show the Vortex transformation along the Tube and support the hypothesis proposed in previous study.
R Kelso - One of the best experts on this subject based on the ideXlab platform.
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Experimental study of the flow structure in a Vortex Tube
2020Co-Authors: Maziar Arjomandi, R KelsoAbstract:With the single injection, a Vortex Tube generates cold and hot stream from two exits respectively, which was first found and investigated by Ranque. Different explanations for the temperature separation in a Vortex Tube have been proposed since the invention of the device. However, due to the difference and conflicts among those explanations, a clarification of the thermal separation is still required. Understanding of the flow behaviour inside a Vortex Tube is an essential requirement in exploring the thermal separation. This paper reports on an experimental study in progress exploring the flow structure in a Vortex Tube. Flow properties in a Vortex Tube are measured and used to clarify the flow structure inside the Tube. The velocity distributions along the Tube are presented, which are different from previous studies. The transition from a forced Vortex at the cold end to a free Vortex near the hot end was first observed, which agrees with the author's previous study. The flow structures found in this research show positive supports for the proposed hypothesis of the temperature separation in the Vortex Tube.
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energy analysis within a Vortex Tube
Experimental Thermal and Fluid Science, 2014Co-Authors: Maziar Arjomandi, R KelsoAbstract:The generation of separated cold and hot streams from a single injection in a Vortex Tube is known as the Ranque effect. Since its invention, several explanations concerning the phenomenon of thermal separation in a Vortex Tube have been proposed, however there has not been a consensus, due to the complexity of the physical process inside the Tube. This paper proposes an explanation for the temperature separation in a Vortex Tube based on an experimental study focusing on the flow structure and energy analysis inside the Tube. Using the measured flow properties inside the Tube, the exergy density distribution along the Vortex Tube was calculated, from which the reasons for the temperature separation were identified. The good agreement of the exergy density analysis with findings from other experimental work supports the validity of the proposed hypothesis.
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the working principle of a Vortex Tube
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Maziar Arjomandi, R KelsoAbstract:The generation of cold and hot streams from a single injection in a Vortex Tube has been investigated by many researchers, aiming to define the primary reasons for the separation. This paper reports a detailed description of the flow behaviour inside a Vortex Tube and addresses the mechanism for the generation of cold and hot streams in a Vortex Tube, which is confirmed by different experimental methodologies, including visualization of the flow structure in a water-operated Vortex Tube, and measurement of velocity profiles in both water- and air-operated Vortex Tubes. Estimation of the theoretical temperature drop based on the pressure gradient of a forced Vortex flow is addressed in this paper, and good agreement with the experimental results was observed. Exergy analysis of the flow properties in an air-operated Vortex Tube indicates that there is no outward energy transfer in the hot region of the Vortex Tube. Furthermore, the governing factor for the temperature rise is attributed to the stagnation and mixture of the flow structure. Based on the proposed mechanism, the predicted performance of the Vortex Tube with variable geometrical parameters, were congruent with the experimental results, underpinning the validity of the proposed mechanism.
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experimental study of the thermal separation in a Vortex Tube
Experimental Thermal and Fluid Science, 2013Co-Authors: Maziar Arjomandi, R KelsoAbstract:A Vortex Tube, a simple mechanical device capable of generating separated cold and hot fluid streams from a single injection, has been used in many applications, such as heating, cooling, and mixture separation. To explain its working principle, both experimental and numerical investigations have been undertaken and several explanations for the temperature separation in have been proposed. However, due to the complexity of the physical process in the Vortex Tube, these explanations do not agree with each other well and there has not been a consensus. This paper presents an experimental study of the flow properties in a Vortex Tube focusing on the thermal separation and energy transfer inside the Tube. A better understanding of the flow structure inside the Tube was achieved, based on the observed three-dimensional velocity, turbulence intensity, temperature and pressure distributions. The gradual transformation of a forced Vortex near the inlet to a free Vortex at the hot end is reported in this work. The calculated exergy distribution inside the Vortex Tube indicates that kinetic energy transformation outwards from the central flow contributes to the temperature separation. Experimental results found in this research show a direct relationship between the formation of hot and cold streams and the Vortex transformation along the Tube.
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experimental study of the flow structure in a counter flow ranque hilsch Vortex Tube
International Journal of Heat and Mass Transfer, 2012Co-Authors: Maziar Arjomandi, R KelsoAbstract:Abstract The mechanism of the temperature separation in a Ranque–Hilsch Vortex Tube has been investigated since the discovery of this phenomenon. In spite of being investigated by many researchers, no consensus has yet been reached regarding the mechanism’s hypothesis. This paper reports on a study in progress exploring the temperature separation in a counter-flow Vortex Tube. The effects of the geometrical parameters, including inlet nozzles, cold exit, hot exit and length of the Tube, were investigated, which indicated the settings for the best performance of the Vortex Tube. Flow properties in the Vortex Tube were measured and used to understand the flow structure inside the Tube. Accurate measurements of the three-dimensional velocity distribution in the Tube were conducted. The results provided enough evidence that the flow in the Tube consists of a forced Vortex formed near the inlet gradually transforming to a free Vortex at the hot end. Experimental results found in this research show the Vortex transformation along the Tube and support the hypothesis proposed in previous study.
Volkan Kirmaci - One of the best experts on this subject based on the ideXlab platform.
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optimization of counter flow ranque hilsch Vortex Tube performance using taguchi method
International Journal of Refrigeration-revue Internationale Du Froid, 2009Co-Authors: Ahmet Murat Pinar, Onuralp Uluer, Volkan KirmaciAbstract:Abstract This study discusses the application of Taguchi method in assessing maximum temperature gradient for the Ranque–Hilsch counter flow Vortex Tube performance. The experiments were planned based on Taguchi's L27 orthogonal array with each trial performed under different conditions of inlet pressure, nozzle number and fluid type. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression analysis were carried out in order to determine the effects of process parameters and optimal factor settings. Finally, confirmation tests verified that Taguchi method achieved optimization of counter flow Ranque–Hilsch Vortex Tube performance with sufficient accuracy.
Mohammad Sadegh Valipour - One of the best experts on this subject based on the ideXlab platform.
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numerical analysis of the curvature effects on ranque hilsch Vortex Tube refrigerators
Applied Thermal Engineering, 2014Co-Authors: M Bovand, Mohammad Sadegh Valipour, Kevser Dincer, Ali TamayolAbstract:Abstract In this paper, the effect of curvature on the performance of Vortex Tubes is investigated numerically. The study was conducted on curvature angles of 0 and 110°. The model is three dimensional and utilizes the RNG k–ɛ turbulence model for determining the flow and temperature fields. The CFD model is verified through comparison with experimental data reported by the authors previously. The code was then utilized to study the effects of radius and angle of curvature on the performance of Vortex Tube. The results show that the efficiency of straight Vortex Tube is higher than the curved Vortex Tube with angle of 110°. The actual values and CFD model results indicated that CFD model can be successfully used for the determination of heating and cooling performances of curvature effects on Ranque–Hilsch Vortex Tube.
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numerical analysis for curved Vortex Tube optimization
International Communications in Heat and Mass Transfer, 2014Co-Authors: M Bovand, Mohammad Sadegh Valipour, Smith Eiamsaard, Ali TamayolAbstract:Abstract Vortex Tubes hold promise for developing low cost refrigeration and air conditioning systems. They do not require the use of any moving parts. Moreover, they also do not consume energy when compressed air is available. In this study, a CFD is conducted to determine the effect of Vortex Tube curvature on their performance. A three dimensional CFD model that utilizes the RNG k-e turbulence model is employed for the numerical simulations. The flow and temperature field in curved Vortex Tubes with curvature angles are simulated in the range of 0° (straight) to 150°. The tangential (swirl), axial velocity components and flow patterns including secondary circulation flow are evaluated. The numerical simulations are verified through comparison with experimental data reported in the literature. The results are then used for evaluating the coefficient of performance (COP) of the Vortex Tube as a cooling solution.
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experimental modeling of a curved ranque hilsch Vortex Tube refrigerator
International Journal of Refrigeration-revue Internationale Du Froid, 2011Co-Authors: Mohammad Sadegh Valipour, Nima NiaziAbstract:Abstract Vortex Tube is a mechanical device that operates as a refrigerating machine. This device separates a compressed gas stream into hot and cold streams. In this paper a series of experiments has been carried out to investigate the influence of uniform curvature of main Tube on the performance of the Vortex Tube. Results show that the curvature in the main Tube has different effects on the performance of the Vortex Tube depending on inlet pressure and cold mass ratio. It was found that the maximum temperature difference (ΔTc,max) belonged to straight Vortex Tube, type A, however the maximum refrigeration capacity ( Q ˙ c , max ) belonged to curved Vortex Tube, type C. Non-dimensional cold temperature difference ( Δ T c / Δ T c , max ) and non-dimensional refrigeration capacity ( Q ˙ c / Q ˙ c , max ) are found to be independent of the curvature of the Vortex Tube.
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Experimental modeling of a curved Ranque–Hilsch Vortex Tube refrigerator
International Journal of Refrigeration-revue Internationale Du Froid, 2011Co-Authors: Mohammad Sadegh Valipour, Nima NiaziAbstract:Abstract Vortex Tube is a mechanical device that operates as a refrigerating machine. This device separates a compressed gas stream into hot and cold streams. In this paper a series of experiments has been carried out to investigate the influence of uniform curvature of main Tube on the performance of the Vortex Tube. Results show that the curvature in the main Tube has different effects on the performance of the Vortex Tube depending on inlet pressure and cold mass ratio. It was found that the maximum temperature difference (ΔTc,max) belonged to straight Vortex Tube, type A, however the maximum refrigeration capacity ( Q ˙ c , max ) belonged to curved Vortex Tube, type C. Non-dimensional cold temperature difference ( Δ T c / Δ T c , max ) and non-dimensional refrigeration capacity ( Q ˙ c / Q ˙ c , max ) are found to be independent of the curvature of the Vortex Tube.
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experimental modeling of Vortex Tube refrigerator
Applied Thermal Engineering, 2003Co-Authors: Mohammad Hassan Saidi, Mohammad Sadegh ValipourAbstract:An experimental investigation has been performed to realize thorough behavior of a Vortex Tube system. In this work attention has been focussed on the classification of the parameters affecting Vortex Tube operation. The effective parameters are divided into two different types, namely geometrical and thermo-physical ones. A reliable test rig has been designed and constructed to investigate the effect of geometrical parameters i.e. diameter and length of main Tube, diameter of outlet orifice, shape of entrance nozzle. Thermo-physical parameters which have been designated and studied are inlet gas pressure, type of gas, cold gas mass ratio and moisture of inlet gas. The effects of these parameters on the cold temperature difference and efficiency are discussed and presented.
Ali Tamayol - One of the best experts on this subject based on the ideXlab platform.
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numerical analysis of the curvature effects on ranque hilsch Vortex Tube refrigerators
Applied Thermal Engineering, 2014Co-Authors: M Bovand, Mohammad Sadegh Valipour, Kevser Dincer, Ali TamayolAbstract:Abstract In this paper, the effect of curvature on the performance of Vortex Tubes is investigated numerically. The study was conducted on curvature angles of 0 and 110°. The model is three dimensional and utilizes the RNG k–ɛ turbulence model for determining the flow and temperature fields. The CFD model is verified through comparison with experimental data reported by the authors previously. The code was then utilized to study the effects of radius and angle of curvature on the performance of Vortex Tube. The results show that the efficiency of straight Vortex Tube is higher than the curved Vortex Tube with angle of 110°. The actual values and CFD model results indicated that CFD model can be successfully used for the determination of heating and cooling performances of curvature effects on Ranque–Hilsch Vortex Tube.
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numerical analysis for curved Vortex Tube optimization
International Communications in Heat and Mass Transfer, 2014Co-Authors: M Bovand, Mohammad Sadegh Valipour, Smith Eiamsaard, Ali TamayolAbstract:Abstract Vortex Tubes hold promise for developing low cost refrigeration and air conditioning systems. They do not require the use of any moving parts. Moreover, they also do not consume energy when compressed air is available. In this study, a CFD is conducted to determine the effect of Vortex Tube curvature on their performance. A three dimensional CFD model that utilizes the RNG k-e turbulence model is employed for the numerical simulations. The flow and temperature field in curved Vortex Tubes with curvature angles are simulated in the range of 0° (straight) to 150°. The tangential (swirl), axial velocity components and flow patterns including secondary circulation flow are evaluated. The numerical simulations are verified through comparison with experimental data reported in the literature. The results are then used for evaluating the coefficient of performance (COP) of the Vortex Tube as a cooling solution.
