The Experts below are selected from a list of 12726 Experts worldwide ranked by ideXlab platform
Tao Yu - One of the best experts on this subject based on the ideXlab platform.
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a study on ceiling temperature distribution and critical exhaust Volumetric Flow Rate in a long distance subway tunnel fire with a two point extraction ventilation system
Energies, 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang Yu, Yanping Yuan, Tao YuAbstract:Smoke control is a crucial issue in a long-distance subway tunnel fire, and a two-point extraction ventilation system is an effective way to solve this problem, due to the characteristics of controlling the smoke in a limited area and removing high-temperature and toxic smoke in time. In this study, the ceiling temperature distribution and the critical exhaust Volumetric Flow Rate to control the smoke in the zone between two extraction vents were investigated in a long-distance subway tunnel fire with a two-point extraction ventilation system. Experiments were carried out in a 1/20 reduced-scale tunnel model based on Froude modeling. Factors, including the heat release Rate (HRR), the extraction vent length, the internal distance between two extraction vents and exhaust Volumetric Flow Rate, were studied. Smoke temperature below the ceiling, exhaust Volumetric Flow Rate and smoke spreading configurations were measured. The ceiling temperature distribution was analyzed. Meanwhile, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on the one-dimensional theory, experimental phenomenon and the analysis of forces acting at the smoke underneath the extraction vent. The coefficients in the empirical equation were determined by experimental data. Compared with the experimental results, the developed empirical equation can predict the critical exhaust Volumetric Flow Rate well. Research outcomes in this study will be beneficial to the design and application of two-point extraction ventilation system for a long-distance subway tunnel fire.
Peng Zhao - One of the best experts on this subject based on the ideXlab platform.
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a study on ceiling temperature distribution and critical exhaust Volumetric Flow Rate in a long distance subway tunnel fire with a two point extraction ventilation system
Energies, 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang Yu, Yanping Yuan, Tao YuAbstract:Smoke control is a crucial issue in a long-distance subway tunnel fire, and a two-point extraction ventilation system is an effective way to solve this problem, due to the characteristics of controlling the smoke in a limited area and removing high-temperature and toxic smoke in time. In this study, the ceiling temperature distribution and the critical exhaust Volumetric Flow Rate to control the smoke in the zone between two extraction vents were investigated in a long-distance subway tunnel fire with a two-point extraction ventilation system. Experiments were carried out in a 1/20 reduced-scale tunnel model based on Froude modeling. Factors, including the heat release Rate (HRR), the extraction vent length, the internal distance between two extraction vents and exhaust Volumetric Flow Rate, were studied. Smoke temperature below the ceiling, exhaust Volumetric Flow Rate and smoke spreading configurations were measured. The ceiling temperature distribution was analyzed. Meanwhile, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on the one-dimensional theory, experimental phenomenon and the analysis of forces acting at the smoke underneath the extraction vent. The coefficients in the empirical equation were determined by experimental data. Compared with the experimental results, the developed empirical equation can predict the critical exhaust Volumetric Flow Rate well. Research outcomes in this study will be beneficial to the design and application of two-point extraction ventilation system for a long-distance subway tunnel fire.
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Effect of Extraction Vent Length on Critical Exhaust Volumetric Flow Rate in Long-distance Subway Tunnel Fires with Two-point Extraction Ventilation
2019 9th International Conference on Fire Science and Fire Protection Engineering (ICFSFPE), 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang YuAbstract:In recent years, point extraction ventilation mode is considered as a competitive alternative to control the smoke in the tunnel fire. The principle of point extraction ventilation is that sufficient exhaust Volumetric Flow Rate is supplied to confine the smoke to an acceptable zone. However, the issue of an appropriate exhaust Volumetric Flow Rate to confine the smoke to a safe zone has not been studied sufficiently. In this study, the critical exhaust Volumetric Flow Rate to control the smoke to the zone between two extraction vents was proposed and a series of small-scale experiments were carried out to investigate the effect of extraction vent length on the critical exhaust Volumetric Flow Rate. The heat release Rate (HRR), extraction vent length and the distance between two vents varied during the tests. Smoke temperature below the ceiling and smoke configurations were measured and analyzed. Experimental results show that it is not the case that the longer the extraction vent, the smaller the critical exhaust Volumetric Flow Rate. There exists a critical extraction vent length that is 0.1 m in the current study. Finally, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on theoretical analysis. The coefficients in the equation were determined by experimental data. Compared with experimental data, it is obvious that the derived equation can well predict the critical exhaust Volumetric Flow Rate. Research outcomes can provide some helpful references for the design of point extraction ventilation in the tunnel fire.
John P W Stark - One of the best experts on this subject based on the ideXlab platform.
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the sensitivity of Volumetric Flow Rate to applied voltage in cone jet mode electrospray and the influence of solution properties and emitter geometry
Physics of Fluids, 2006Co-Authors: Katharine Smith, Matthew S Alexander, John P W StarkAbstract:A high accuracy online Flow Rate measurement system has been used to demonstRate the effect of applied voltage, Vapp, on the Volumetric Flow Rate, Q, through an electrospray system. Several solutions of the organic solvents ethylene and triethylene glycols doped with sodium iodide to give varying conductivities in the range of 0.0025–0.23S∕m have been sprayed. It was established for the first time that solution conductivity has no appreciable effect on the sensitivity of Flow Rate to applied voltage in the cone-jet mode of electrospray. However, it appears that even when the hydraulic resistance is taken into account, the sensitivity of Flow Rate as controlled by the applied voltage is additionally related to the emitter exit geometry. These findings are of particular importance to both spacecraft propulsion and electrospray mass spectrometry technologies and suggest careful emitter geometry design considerations will lead to greater control over electrospray properties.
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voltage effects on the Volumetric Flow Rate in cone jet mode electrospraying
Journal of Applied Physics, 2006Co-Authors: Katharine Smith, Matthew S Alexander, John P W StarkAbstract:Electrospray data collected demonstRate the detailed dependence of Volumetric Flow Rate through an electrospray system upon the applied voltage. The sensitivity of nominal Flow Rate to applied voltage was found to be higher for lower nominal Flow Rates. For a Volumetric Flow Rate ∼4nL∕s a 25% change in Flow Rate per kilovolt was recorded over a cone-jet mode stability range spanning ∼1.5kV. This Volumetric Flow Rate voltage sensitivity holds particular significance for potential colloid electrospray propulsion systems, which opeRate at or near minimum Flow Rate conditions. Analysis is presented to show that the change in Flow Rate due to change in voltage cannot be ascribed to evaporation from the meniscus as has been suggested by others.
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voltage effects on the Volumetric Flow Rate and thrust produced in electrospray propulsion systems
In: International Electric Propulsion Conference; Princeton New Jersey USA. 2005., 2005Co-Authors: Matthew S Alexander, Katharine Smith, John P W StarkAbstract:The effect of extractor voltage on the propellant Flow Rate through an ES emitter has been determined for a tri-ethylene glycol sodium iodide solution using an in-line high accuracy Flow measurement system. In these experiments a nominally fixed Flow Rate, obtained by providing a fixed supply pressure, is observed to be influenced by the applied voltage during electrospray production. The relative sensitivity of this ‘nominal’ Flow Rate to applied voltage was found to be higher as the nominal Flow Rate decreased. This Volumetric Flow Rate sensitivity holds particular significance for colloidal ES thruster systems, which opeRate at or near minimum Flow Rate conditions.
Nanyang Yu - One of the best experts on this subject based on the ideXlab platform.
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a study on ceiling temperature distribution and critical exhaust Volumetric Flow Rate in a long distance subway tunnel fire with a two point extraction ventilation system
Energies, 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang Yu, Yanping Yuan, Tao YuAbstract:Smoke control is a crucial issue in a long-distance subway tunnel fire, and a two-point extraction ventilation system is an effective way to solve this problem, due to the characteristics of controlling the smoke in a limited area and removing high-temperature and toxic smoke in time. In this study, the ceiling temperature distribution and the critical exhaust Volumetric Flow Rate to control the smoke in the zone between two extraction vents were investigated in a long-distance subway tunnel fire with a two-point extraction ventilation system. Experiments were carried out in a 1/20 reduced-scale tunnel model based on Froude modeling. Factors, including the heat release Rate (HRR), the extraction vent length, the internal distance between two extraction vents and exhaust Volumetric Flow Rate, were studied. Smoke temperature below the ceiling, exhaust Volumetric Flow Rate and smoke spreading configurations were measured. The ceiling temperature distribution was analyzed. Meanwhile, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on the one-dimensional theory, experimental phenomenon and the analysis of forces acting at the smoke underneath the extraction vent. The coefficients in the empirical equation were determined by experimental data. Compared with the experimental results, the developed empirical equation can predict the critical exhaust Volumetric Flow Rate well. Research outcomes in this study will be beneficial to the design and application of two-point extraction ventilation system for a long-distance subway tunnel fire.
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Effect of Extraction Vent Length on Critical Exhaust Volumetric Flow Rate in Long-distance Subway Tunnel Fires with Two-point Extraction Ventilation
2019 9th International Conference on Fire Science and Fire Protection Engineering (ICFSFPE), 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang YuAbstract:In recent years, point extraction ventilation mode is considered as a competitive alternative to control the smoke in the tunnel fire. The principle of point extraction ventilation is that sufficient exhaust Volumetric Flow Rate is supplied to confine the smoke to an acceptable zone. However, the issue of an appropriate exhaust Volumetric Flow Rate to confine the smoke to a safe zone has not been studied sufficiently. In this study, the critical exhaust Volumetric Flow Rate to control the smoke to the zone between two extraction vents was proposed and a series of small-scale experiments were carried out to investigate the effect of extraction vent length on the critical exhaust Volumetric Flow Rate. The heat release Rate (HRR), extraction vent length and the distance between two vents varied during the tests. Smoke temperature below the ceiling and smoke configurations were measured and analyzed. Experimental results show that it is not the case that the longer the extraction vent, the smaller the critical exhaust Volumetric Flow Rate. There exists a critical extraction vent length that is 0.1 m in the current study. Finally, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on theoretical analysis. The coefficients in the equation were determined by experimental data. Compared with experimental data, it is obvious that the derived equation can well predict the critical exhaust Volumetric Flow Rate. Research outcomes can provide some helpful references for the design of point extraction ventilation in the tunnel fire.
Zhongyuan Yuan - One of the best experts on this subject based on the ideXlab platform.
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a study on ceiling temperature distribution and critical exhaust Volumetric Flow Rate in a long distance subway tunnel fire with a two point extraction ventilation system
Energies, 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang Yu, Yanping Yuan, Tao YuAbstract:Smoke control is a crucial issue in a long-distance subway tunnel fire, and a two-point extraction ventilation system is an effective way to solve this problem, due to the characteristics of controlling the smoke in a limited area and removing high-temperature and toxic smoke in time. In this study, the ceiling temperature distribution and the critical exhaust Volumetric Flow Rate to control the smoke in the zone between two extraction vents were investigated in a long-distance subway tunnel fire with a two-point extraction ventilation system. Experiments were carried out in a 1/20 reduced-scale tunnel model based on Froude modeling. Factors, including the heat release Rate (HRR), the extraction vent length, the internal distance between two extraction vents and exhaust Volumetric Flow Rate, were studied. Smoke temperature below the ceiling, exhaust Volumetric Flow Rate and smoke spreading configurations were measured. The ceiling temperature distribution was analyzed. Meanwhile, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on the one-dimensional theory, experimental phenomenon and the analysis of forces acting at the smoke underneath the extraction vent. The coefficients in the empirical equation were determined by experimental data. Compared with the experimental results, the developed empirical equation can predict the critical exhaust Volumetric Flow Rate well. Research outcomes in this study will be beneficial to the design and application of two-point extraction ventilation system for a long-distance subway tunnel fire.
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Effect of Extraction Vent Length on Critical Exhaust Volumetric Flow Rate in Long-distance Subway Tunnel Fires with Two-point Extraction Ventilation
2019 9th International Conference on Fire Science and Fire Protection Engineering (ICFSFPE), 2019Co-Authors: Peng Zhao, Zhongyuan Yuan, Nanyang YuAbstract:In recent years, point extraction ventilation mode is considered as a competitive alternative to control the smoke in the tunnel fire. The principle of point extraction ventilation is that sufficient exhaust Volumetric Flow Rate is supplied to confine the smoke to an acceptable zone. However, the issue of an appropriate exhaust Volumetric Flow Rate to confine the smoke to a safe zone has not been studied sufficiently. In this study, the critical exhaust Volumetric Flow Rate to control the smoke to the zone between two extraction vents was proposed and a series of small-scale experiments were carried out to investigate the effect of extraction vent length on the critical exhaust Volumetric Flow Rate. The heat release Rate (HRR), extraction vent length and the distance between two vents varied during the tests. Smoke temperature below the ceiling and smoke configurations were measured and analyzed. Experimental results show that it is not the case that the longer the extraction vent, the smaller the critical exhaust Volumetric Flow Rate. There exists a critical extraction vent length that is 0.1 m in the current study. Finally, an empirical equation was developed to predict the critical exhaust Volumetric Flow Rate based on theoretical analysis. The coefficients in the equation were determined by experimental data. Compared with experimental data, it is obvious that the derived equation can well predict the critical exhaust Volumetric Flow Rate. Research outcomes can provide some helpful references for the design of point extraction ventilation in the tunnel fire.
