The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Dídia Covas - One of the best experts on this subject based on the ideXlab platform.
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Experimental distinction of damping mechanisms during hydraulic transients in pipe flow
Journal of Fluids and Structures, 2016Co-Authors: David Ferras, Pedro Manso, Anton Schleiss, Dídia CovasAbstract:Abstract The aim of the present paper is to contribute to the identification of the principal mechanical–hydraulical relationships during hydraulic transients by means of the analysis of observed transient pressure and strain waves in different pipe rigs. Four different experimental set-ups are analysed: a straight Copper pipe with either moving or anchored downstream pipe-end, a Coil Copper pipe and a Coil polyethylene pipe. Discussion highlights differences in the response of each system in terms of wave shape, damping, and dispersion. The straight Copper pipe behaviour, for an anchored pipe-end, has shown the closest dynamic response to the expected one from classical waterhammer theory, being unsteady friction the most relevant damping mechanism. Fluid structure interaction dominates when the valve is released in the straight Copper pipe and also has an important role in the Coil Copper pipe. Viscoelasticity dominates in the polyethylene pipe.
David Ferras - One of the best experts on this subject based on the ideXlab platform.
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Experimental distinction of damping mechanisms during hydraulic transients in pipe flow
Journal of Fluids and Structures, 2016Co-Authors: David Ferras, Pedro Manso, Anton Schleiss, Dídia CovasAbstract:Abstract The aim of the present paper is to contribute to the identification of the principal mechanical–hydraulical relationships during hydraulic transients by means of the analysis of observed transient pressure and strain waves in different pipe rigs. Four different experimental set-ups are analysed: a straight Copper pipe with either moving or anchored downstream pipe-end, a Coil Copper pipe and a Coil polyethylene pipe. Discussion highlights differences in the response of each system in terms of wave shape, damping, and dispersion. The straight Copper pipe behaviour, for an anchored pipe-end, has shown the closest dynamic response to the expected one from classical waterhammer theory, being unsteady friction the most relevant damping mechanism. Fluid structure interaction dominates when the valve is released in the straight Copper pipe and also has an important role in the Coil Copper pipe. Viscoelasticity dominates in the polyethylene pipe.
Chang-hyo Son - One of the best experts on this subject based on the ideXlab platform.
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Heat Transfer Characteristics of Inclined Helical Coil Type Heat Exchanger
Journal of the Korean Society of Marine Engineering, 2007Co-Authors: Chang-hyo Son, Min-ju Jeon, Seong-il JangAbstract:The heat transfer coefficient and Pressure drop during gas cooling process of (R-744) in inclined helical Coil Copper tubes were investigated experimentally. The main components of the refrigerant loop are a receiver. a variable-speed pump. a mass flow meter, a pre-heater and a inclined helical Coil type gas cooler (test section). The test section consists of a smooth Copper tube of 2.45mm inner diameter. The refrigerant mass fluxes were varied from 200 to and the inlet Pressures of gas cooler were 7.5 to 10.0 [MPa]. The heat transfer coefficients of in the inclined helical Coil tubes increases with the increase of mass flux and gas cooling pressure of . The pressure drop of in the gas cooler shows a relatively good agreement with those Predicted by Ito`s correlation developed for single-phase in a helical Coil tube. The local heat transfer coefficient of agrees well with the correlation by Pitla et al. However, at the region near pseudo-critical temperature. the experiments indicate higher values than the Pitla et al. correlation. Therefore. various experiments in the inclined helical Coil tubes have to be conducted and it is necessary to develop the reliable and accurate prediction determining the heat transfer and pressure drop of in the inclined helical Coil tubes.
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Heat Transfer Characteristics of Carbon Dioxide in a Inclined Helical Coil Type Heat Exchanger with Inner Diameter Tube of 4.55 mm
2007Co-Authors: Chang-hyo SonAbstract:The heat transfer coefficient and pressure drop during gas cooling process of (R-744) in inclined helical Coil Copper tubes were investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and a inclined helical Coil type gas cooler (test section). The test section consists of a smooth Copper tube, which is specified as the inner diameter of 4.55 mm. The refrigerant mass fluxes were varied from 200 to and the inlet pressures of gas cooler were done 7.5 to 10.0 (MPa). The heat transfer coefficients of in the inclined helical Coil tubes increase with the increase of mass flux and gas cooling pressure of . The pressure drop of in the gas cooler shows relatively good coincidence with those predicted by Ito's correlation developed for single-phase in a helical Coil tube. The local heat transfer coefficient of is well coincident with the correlation by Pitla et al. However, at the region near pseudo-critical temperature, the experiments indicate higher values than the Pitla et al. correlation.
Pedro Manso - One of the best experts on this subject based on the ideXlab platform.
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Experimental distinction of damping mechanisms during hydraulic transients in pipe flow
Journal of Fluids and Structures, 2016Co-Authors: David Ferras, Pedro Manso, Anton Schleiss, Dídia CovasAbstract:Abstract The aim of the present paper is to contribute to the identification of the principal mechanical–hydraulical relationships during hydraulic transients by means of the analysis of observed transient pressure and strain waves in different pipe rigs. Four different experimental set-ups are analysed: a straight Copper pipe with either moving or anchored downstream pipe-end, a Coil Copper pipe and a Coil polyethylene pipe. Discussion highlights differences in the response of each system in terms of wave shape, damping, and dispersion. The straight Copper pipe behaviour, for an anchored pipe-end, has shown the closest dynamic response to the expected one from classical waterhammer theory, being unsteady friction the most relevant damping mechanism. Fluid structure interaction dominates when the valve is released in the straight Copper pipe and also has an important role in the Coil Copper pipe. Viscoelasticity dominates in the polyethylene pipe.
Anton Schleiss - One of the best experts on this subject based on the ideXlab platform.
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Experimental distinction of damping mechanisms during hydraulic transients in pipe flow
Journal of Fluids and Structures, 2016Co-Authors: David Ferras, Pedro Manso, Anton Schleiss, Dídia CovasAbstract:Abstract The aim of the present paper is to contribute to the identification of the principal mechanical–hydraulical relationships during hydraulic transients by means of the analysis of observed transient pressure and strain waves in different pipe rigs. Four different experimental set-ups are analysed: a straight Copper pipe with either moving or anchored downstream pipe-end, a Coil Copper pipe and a Coil polyethylene pipe. Discussion highlights differences in the response of each system in terms of wave shape, damping, and dispersion. The straight Copper pipe behaviour, for an anchored pipe-end, has shown the closest dynamic response to the expected one from classical waterhammer theory, being unsteady friction the most relevant damping mechanism. Fluid structure interaction dominates when the valve is released in the straight Copper pipe and also has an important role in the Coil Copper pipe. Viscoelasticity dominates in the polyethylene pipe.